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Discussion Starter · #1 ·
Hello guys I was wondering has anybody used these Felpro 1205s3 intake gaskets before? These are the same as the traditional 1205 but its steel laminated and I was thinking of using these in place of the 1205 intake gaskets. I had a successful seal on my intake on the third time and had no issues and kept checking the torque and it stayed at 25 ftlbs and did not have any problems. But recently I ran it and it was still leak free and was just fine when I turned my truck off and it was on a 70 degree day. Unfortunately here it has been swinging in the temperatures where it can be warm the one day and then over night it gets to freezing with near zero windchill.

My intake had no leaks prior to it getting cold a few weeks ago and I have been checking things over every day almost before and after running it and has went through several heat cycles and I have been on the torque and it has held just fine for a month. I had been checking it at least three times a week with a torque wrench for over a month.

I had leaks since day one on this build and its too long of a story but finally got it to seal good on both sides of the front coolant ports. Has only weeped at the top of the gaskets only and in the front at first on both sides and then after three tries I have not had any more on the driver side but the passenger side was fine for over a month since the reseal and was fine until I had it out and drove through several heat cycles and it was fine.

Was on a warm day and then it cooled from 70 degrees one day to near zero with less then 48 hours. When I turned it off I let it sit for a while and there was no pressure in the system as I checked my antifreeze and had my radiator cap off. I left it sit for about four days or so.

After that I went out to check things and pull my carb off to work on and somehow the system must have built pressure up and from what I could tell the dang passenger side intake gasket above the coolant port that sticks out had some antifreeze bubbles sitting in just one tiny spot of a few bubbles there. I looked at my coolant hose and it was not leaking and still tight. I checked my other side on the driver side and its was still fine.

This is the fourth time for this and everything has checked out just fine and only can think of it somehow that as it was on a warmer day it was sealing fine and then from the extreme temperature change it allowed enough of shrinking on the gaskets somehow on the gasket maker that it must have pulled away from the intake manifold as it seems to come between it and the intake where its weeping at on the passenger side.

The driver side has been fine for the last three times but the passenger side sealed just fine at first and went through at least 6 heat cycles or so and near 30 miles with stop and go driving and several start up and shut downs before parking it and sitting for several days or a week and no issues even with temperature swings.

A week and a half ago is when I was ok on a Wednesday and it was warm out then by Friday it got down to hardly 20 degrees during the day and then the gasket started to let it weep once again just on the one side. It somehow built up pressure as it was dry and clean and held torque at 25 ftlbs before it started to weep again after sitting for a few days since the last time I had it running.

Before it leaked it had little dimple spots where the RTV pushed out and sealed dried from the last install.It looked like the driver side in the photo before I added some more rtv over top of the tiny area where it weeped again.I took a Qtip and dabbed it and cleaned it up with cleaner and on that top spot and took some 90 minute right stuff gasket maker and took a toothpick and smoothed some gasket maker over top of the area on top of the intake gasket where it sticks out and this was on nice 70 degree day and I have not ran it since that time but I no longer have any weeping out since doing that but I am sure its only a band aid and won't hold for long and might weep again or worse the gasket go bad and leak internally. The spot where I put the gasket maker you can see in the picture where I got a smooth spot put there and it sealed after that and no more weeping for now.

Seems like to me these gaskets are having an issue for some reason with being ok when its warm out and then going to extreme cold somehow to near zero degree does not allow enough shrinkage of the gasket with expansion and contraction of just sitting without ending up going bad for some reason. I never had this do that before especially after the third time working at first and doing ok during temperature swings just sitting and now it went bad all of a sudden.


The gasket never leaked while running or showed any seeping anywhere on that spot. Only caught it like stated as it showed no signs before it got cold out. There were no signs of the gasket on the passenger side going bad and looked no different then it sealed before weeping again. Sealed fine for a a month plus running through several heat cycles and then it just gets super cold again one time and even checked torque and it was still fine and now this once again.
My question is I am tired of having issues with these Felpro gaskets and wondered if the steel laminated 1205s3 gaskets would be better and less chance of this happening?


 

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Aftermarket aluminum head’s and intake is my take?

These are often a problem especially if the block has also been decked and or a thin head gasket is used.

This lowers the head’s relative to the intake and brings them closer together while the intake gets held relatively high as it registers on the china walls and or gets pinched by the head’s coming closer together. At some point the intake needs to be milled sides and bottom to correct this. Knowing the details of whore head’s, intake, head gasket an whether the head’s and or block have been milled and by how much is useful info.

Another coolant leakage source is not using sealer on the bolts, the head’s threads are open to the coolant passages which will leak.

Bogie
 

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Discussion Starter · #3 ·
Hello Bogie I have used sealant on all the bolts and no problems there. Also the heads were never decked and also the block was only decked .012 or so and still has a deck on it of 9.015 ish and I use a .041 compressed head gasket fel pro 1003. That should not be a problem. These heads were used on my previous 377 shp build and also that block was the same deck height and never any problems with sealing things.

Like stated it sealed at first and had no problems even after several heat cycles. It just decided to one day over night just poof out like that for some stupid reason. Everything was checked again and looked over even more before the intake was stuck back on and it showed all is good. The intake valley lines up real well with the angle of the heads at the China walls. The bolt holes line up as well without any problems. The intake sat nice and flush with the heads and no wobble what so ever and checked it looking from the front and no sighs of it sitting to high.

From my understanding you have to have a good bit before you have to have the intake machined if you heads and blocked decked a bit. I once had a block that was decked to 9.015 and also had about .030 taken off my cast iron heads and it still sealed no problem with a few different intakes on top without them needing to be machined to drop it down some. I think something is just not right with the gaskets wanting to be soft enough to compress and expand as it sits in different temperatures as it was fine for about three weeks and then bam. The other side has been fine and the rears has never leaked.

I figure if it was something of a height problem it would not seal at all on the rear but it has been fine. No problems on the last build with the heads and deck height.
 

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Its been awhile so these may not be the port size I used , but they are the gaskets I used , after numerous unsuccessful attempts with the $$$ felpro stuff ,I ordered a couple sets of these ! Careful alignment is key . my TR manifold had seen some hack previous owner(s) hogged out bolt holes , etc . These gasket with rtv on the China walls ,& water ports w/ 30 #ft of torque on brodix ik200 heads , no leaks.!
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Discussion Starter · #7 ·
Well johnsongrass1 why does weiand and edelbrock call for 25ftlbs on there intakes going on aluminum heads? I am not trying to question our experience as you know way more then what I do but from my knowledge it has only been 30 ftlbs on iron heads and not aluminum heads. Is that not a way to warp them with to much torque? Just asking to try and understand from where your coming from with your experience. I have always done 25 ftlbs in the past on iron heads with an aluminum intakes on either iron or aluminum heads and never had a problem with them leaking.

Tell me what is your success on sealing these things. I have always used an older style rtv non quick drying stuff around the coolant ports on both sides of the gaskets and on all four coolant ports and then used a gasket shelack compound on the intake ports on the back off the gaskets facing the heads and also on the intake before putting it down on the engine after I placed a bead across the back an front china walls. I would let the rtv high temp sit in place for about 15 minutes and then place the intake on very carefully and then start to torque the bolts from the center and work my way out and only torque it for about ten ftlbs and let it sit for another 15 minutes and then go through and do the final torque and let it sit for 24 hours and then recheck the torque again and then put the stuff back together and then run it and see how it does.

If this the best method? I am thinking of this time of instead of using the one minute gasket maker rtv and instead of using the 90 minute rtv right stuff gasket maker stuff as it seems to not dry as hard and seems to allow more expansion of the gasket and be more pliable expansion and contraction while sitting and also through heat cycles. The 90 minute stuff seemed easier to work with. The one minute seems to get awful hard compared to the other one.

I have always used rtv around the ports on the coolant part of things but never on the intake runners. My Father was the one who did that and from what I have seen many others seem to do the same. Should I use a different rtv around the coolant ports that is more for antifreeze or is the 90 minute good enough. I am worried about ripping the threads out of the heads and warping my intake from too much torque.
 

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a grade 8 bolt needs 40 ft-lbs to get any stretch at all, and stretch is what keeps it tight. the S3 gasket is more resistant to being pushed out than the all paper gaskets. I use the airplane glue stuff around the intake ports to keep them from moving. for something that might need the intake off and on I spray the intake with dry film moly so nothing sticks to it, and usually you can get it off and on without replacing the gasket or the RTV.
 

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I don't know why they are all wrong, but they are. Likely more internet BS copy and paste crap or attorneys looking at the idiots that think that if 35/40 is good, 145 will really be better?
The internet is full of BS everywhere. Plenty of good stuff too, but you have to weed out the crap.

I've installed 1000's maybe, intakes, steel, cast, alloys, small, big, cheap, expensive, all of em. DRY.....Gasket only, perhaps a pencil eraser sized drop of silly cone between the bolts, in two places to hold the gasket in place for assembly only and haven't had one come back yet.
You have silly cone all over, not enough to bolt torque, who knows if they are flat or not and saying "my pappy has been doing it this way for...." Pappy was wrong and taught you wrong, the others doing it are doing it wrong too.

Directions.......
Intake surface needs to be flat and the correct RA
Heads needs to be flat and the correct RA.
Head and intake faces should be parallel
Use the FP1205 or whatever fits the ports the best, maybe a DAB of something to hold them on the heads for assembly, silly cone, super glue, whatever....I'd throw the silly cone in the trash personally. It's kinda fun to roll up in a ball and throw around the shop.
Grade 5 or 8 bolts with flat washers, I like cap screws personally, as long as I can get them without hitting the pushrods.
Water jacket sealer on the threads, at 35-45lbs.
Don't use the intake to lift the engine on 8 bolt intakes.
THOUSANDS of pro engine builders do it this way daily and don't have problems. You shouldn't either......unless the intake or head is broke.

If that doesn't fix it, I'll buy you the next set of gaskets.

Think about it this way, if you paid $52,000 for an engine and you picked it up with that silly cone crap all smeared all of it to keep it from leaking, would you wonder whats really going on there? That's not professional. Follow the professionals, you likely get professional results. This isn't even the same style intake as yours but its a good example that proper procedures results in proper outcomes and not a DROP of silly cone any where. As far as I'm concerned it causes more problems than it solves.
 

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Running high torque on intake bolts going into aluminum head’s risked pulling the threads out of the heads. Really high quality head’s come with Heli-Coils in the threads which allows pulling more force than is safe on aluminum threads. Grade 5 bolt on the intake is fine. The higher the grade of the fastener the more force is required to get it into the early stretch where the fastener is deforming but not so much that it doesn’t recover. At this point the fastener is acting like an extremely stiff spring where the operating load remains under the spring or preload on the fastener. A place to get into trouble is upgrading the fastener for the job as now more preload must be applied to the fastener to get it into this early yield deformation zone from where when the forces are released it returns to is original dimensions. So without taking say a grade 8 fastener to this point on its yield curve the fastener is essentially loose and will back off with operating loads. At the other end of the spectrum is using a standard hardware store I’m guessing grade 3 fastener which at the needed clamping force is now stretched into or near its failure point and even if it has not failed into multiple pieces it just keeps stretching when working loads are applied.

Looking at pictures of your washer set up, washers between steel fastener heads and aluminum parts either need to be very thick like 1/8 inch or need to be ground and hardened. Hardware store washers simply bend into the softer aluminum as you pull torque so the washer needs to be a very stiff steel thus hardened and extremely flat thus parallel ground. Proper installation against aluminum is to have the washer clean and dry where it mates to the aluminum while the surface between washer and fastener is lubricated. This usually means a grease so the lube doesn’t migrate under the washer. The reason is to lock the washer with the aluminum part with friction so it doesn’t turn with the fastener head or nut thus galling the aluminum. The grease between the top of the washer and fastener head or nut provides a low friction surface that doesn't provide an incorrectly high torque reading against how much fastener stretch that torque reading implies. In other words damaged, dry and or dirty threads and improper or missing lubrication and or washer type under the head or nut leads to a torque reading that may look correct on the wrench gauge but because of excess friction has not properly stretched the fastener so the fastener is actually loose.

Now a topical change into straightness of the head and intake mounting faces, here a good straight edge should show if these surfaces are going to make a dependable seal. Another test is to set the intake in place on china wall gaskets, lightly install the bolts just to orient it to the heads then check at the ends with feeler gauges to see if the upper and lower mate is a consistent thickness or distance along the coolant ports, this checks the angle between the head and intake.

Bogie
 

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Techinspector1 wrote a very good Wiki on here about how to check the fitment of the intake manifold , I don't know if its still available on here & haven't the computer saavy to search what once was a fine forum . Perhaps one of the moderators could find & post it .
 

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Running high torque on intake bolts going into aluminum head’s risked pulling the threads out of the heads. Really high quality head’s come with Heli-Coils in the threads which allows pulling more force than is safe on aluminum threads. Grade 5 bolt on the intake is fine. The higher the grade of the fastener the more force is required to get it into the early stretch where the fastener is deforming but not so much that it doesn’t recover. At this point the fastener is acting like an extremely stiff spring where the operating load remains under the spring or preload on the fastener. A place to get into trouble is upgrading the fastener for the job as now more preload must be applied to the fastener to get it into this early yield deformation zone from where when the forces are released it returns to is original dimensions. So without taking say a grade 8 fastener to this point on its yield curve the fastener is essentially loose and will back off with operating loads. At the other end of the spectrum is using a standard hardware store I’m guessing grade 3 fastener which at the needed clamping force is now stretched into or near its failure point and even if it has not failed into multiple pieces it just keeps stretching when working loads are applied.

Looking at pictures of your washer set up, washers between steel fastener heads and aluminum parts either need to be very thick like 1/8 inch or need to be ground and hardened. Hardware store washers simply bend into the softer aluminum as you pull torque so the washer needs to be a very stiff steel thus hardened and extremely flat thus parallel ground. Proper installation against aluminum is to have the washer clean and dry where it mates to the aluminum while the surface between washer and fastener is lubricated. This usually means a grease so the lube doesn’t migrate under the washer. The reason is to lock the washer with the aluminum part with friction so it doesn’t turn with the fastener head or nut thus galling the aluminum. The grease between the top of the washer and fastener head or nut provides a low friction surface that doesn't provide an incorrectly high torque reading against how much fastener stretch that torque reading implies. In other words damaged, dry and or dirty threads and improper or missing lubrication and or washer type under the head or nut leads to a torque reading that may look correct on the wrench gauge but because of excess friction has not properly stretched the fastener so the fastener is actually loose.

Now a topical change into straightness of the head and intake mounting faces, here a good straight edge should show if these surfaces are going to make a dependable seal. Another test is to set the intake in place on china wall gaskets, lightly install the bolts just to orient it to the heads then check at the ends with feeler gauges to see if the upper and lower mate is a consistent thickness or distance along the coolant ports, this checks the angle between the head and intake.

Bogie
45 isn't high torque for a 2A thread at 75 percent. You'll break a grade 5 bolt before you pull the threads out if everything is ideal for bolt length, threads engagement, sizing, pitch, etc.......Now we all know in realty, something is going to be off a little at a modest 45 pounds, if it pulls the threads out, it wasn't gonna hold up long at 25 either.
I could post the math in my machinists handbook if needed.
 

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Discussion Starter · #13 · (Edited)
Well not to hammer anything my "Pappy" Father has done more engines then I can think of for 50 years from everything foreign and domestic and never had any problems with his work coming back and stuff going bad etc except for common things that can go wrong but nothing out of his way being an incorrect way of doing things to fix stuff and do what is supposed to be done. I am not saying the method he did is wrong and not saying its not all right either. I have seen several ways of doing things and it has worked with how they did it. Nothing personal Johnsonsgrass1 as you are a good guy of knowledge and your opinion does matter to me as does others and our knowledge and is appreciated.

All I do know is before he put this build together when he cleaned up my heads from the last build he used a wire wheel to clean things up some up which I don't prefer and like from watching videos that others have done that before and it worked fine with them but others have not. That was on the head gasket surface and he said he barely touched things. You still could see the RA finish on the heads and he never spent anytime on one spot not even for second. I don't know what he used to clean the intake side of things but before we put this intake on and the engine has already been the truck and not taking out. When it was on the old previous 377 with the previous Edelbrock intake it did not leak at all. Even with whatever method he did for cleaning and sealing.

When we stuck this one on we used razor blades and new ones to not leave any marks and most of the stuff came off and used brake clean to make sure everything was clean. I checked the intake with a straightedge before putting it on and had it at my house. Not even .001 was out of spec. I asked to check the heads but my Father loaned his out so I could not check that. I will check my building small chevy books and as far as looking at it wise the angles matched up on both sides with no gasket on the thing.

I noticed the cylinder head intake surface was smooth and shiny looking and don't know if that has anything to do or not. I am used to cast iron.
As far as doing intakes goes I have done all of mine with only putting silicone around the coolant ports with a thin finger smear of silicone and then using gasket shelack around the intake ports and the bottom rail to hold the gasket in place. That is how I did it the last time back in 2011 the last time I did a cam swap and it sealed fine but this was done in 80 plus degree weather.

Now nothing against my Fathers method or how others do it but I am thinking the silicone is the problem of it becoming so hard that when it expands and then contracts that its not enough to keep things sealed and compressed especially at the front coolant port area since it flows antifreeze through versus the back to where it just sits there but like I said the front driver side has done fine and the rear ports have never leaked either so I don't know for sure. That is with the Right stuff one minute gasket maker I am talking about.

When the gaskets were done the Right stuff one minute was not curing super fast like its supposed to and when installed it just seemed to stay just too soft and not skin over like I am used too. His garage was heated and the engine was slightly warm to the touch after it sat a while we cleaned things up and scrapped the old gaskets off etc.

He worked on the passenger side while I did the driver side. All I did wast take a small amount of rtv and made a thin edge around the coolant ports and he put some around the intake ports as well which I never did any time I ever did it.

The intake was installed and he did not do the torque in steps like I always did. He used his air ratchet and went by feel starting inside out and then tightened the bolts down and went from middle to the rear and then the the other side rear and then progressed to the front and hand tightened all the stuff down with his air ratchet making things tight and left it at that. The gasket maker that squished out the front like normal seemed to not be cured very quickly as it supposed to be quick and ready for service but it felt like it would rip out pretty easy if you were to do so.

We left it cure over night and the next day it felt fine and no issues for nearly a month.

Was fine at first but that does not mean after time the other sides might not eventually leak. I want to do this again but this time with no chance of failure and I am looking at the steel shimmed 1205 gasket. Now on how to do it the best way possible and easiest. Now the plan I have is to use the 90 minute right stuff gasket maker instead of the fast dry one as the last I used it, it seemed to work a lot better but just my opinion.

What I want to do is just put a smear around the coolant ports but just a thin flat smear and nothing super thick. I want to leave the intake ports alone but want to use a gasket sealant to hold the gasket in place but don't know what would be best to use that would help seal the gasket and also keep it in place if I have to move the intake a hair. I want to put the rtv on and let it sit just enough to start to cure and skin but I don't know how much time I would have as I would also have to put the china wall rtv across each end and how long can I let it sit before putting the intake on?

After a tiny seal around the coolant ports I would then put some tack or some sort around the intake ports on the heads and then proceed to put a tiny spot of silicone underneath the part where the intake gasket is square and goes on the china wall on all four corners. They lay the gasket down and then proceed to place a continuous bead across both china walls overlapping the gaskets. Would like to let it cure and skin over but not take too long but just enough. Then place a small square of gasket shelac around the coolant ports on my intake.Then grab my intake and put it on carefully making sure the bolt holes line up fine and not have to move it.

I would then proceed to put rtv on the bolt threads and start to install them one at a time and then get all those bolts in. Then use my torque wrench and torque them down but not to full spec yet and to torque just enough to start the crush yet as would want to fully torque it yet.

I would then let it sit just long enough and then proceed to torque it in three step increments from 15 then to 20 then a final 25 but feel like going up to 30 this time. I won't go anymore then that as sorry but the intake makers say 25 ftlbs and I have always used that in the past but that was with iron heads and never aluminum which would have the threads rip a lot easier.

I plan on letting it sit for a few days before even adding any coolant to it and rechecking the torque. After the first heat cycle I will then plan on re torquing it even before it cools down all the way just to make sure it is tight and good.

If I wanted to use something different around the coolant ports what would be used that is good to cover up any pitting or anything that is not RTV and would seal any imperfections and hold the gasket in place? Thoughts?

That is the about the only way I have always done it but it was always with the 24 hour stuff.
 

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No offense taken, or attempted to give......
My point is SOMETHING went wrong right?
You do it your way a few times and it doesn't work out for too long, it's time to try something else.
Ive seen your way work, Ive seen my way work out a lot more often. Choose wisely I suppose.
 

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Discussion Starter · #15 ·
I agree Johnsongrass1. It was done the way my Father did it but I don't normally do it like that at least in my last cam swaps I did ten plus years back. I also know Bogie what your talking about for checking for clearances when placing the intake on the heads but I forget my specs I had written down before.

My question is I am going to bu a set of the 1205s3 which is a composite gasket that has a .005 steel core inside of it and is .065 thick versus the .060 1205 fel pro gaskets. I was thinking of using something different around the coolant ports but what would work in place of RTV for any imperfections especially if your heads were older and had some slight pitting on the ends?

My Father likes to rush things while I like to take my time and not rush stuff so fast and give things time to dry and I think doing it while it was not very warm out and in a cold garage but with heat was not enough and things were put together to soon even though it was the fast drying one minute gasket maker. It would have never held if I had used it that very same day and had my engine started up. I left it sit over night and it cured at least on what was sticking out the front part of the china wall.

I want to do this as best as possible and I heard Permatex number 2 can be used around the coolant ports and is a gasket sealant type of stuff and I have not used it in years and wonder would it work well? If I can keep it to just RTV at the ends only then that would be nice as less chance of things going wrong at least in theory.

Thanks guys and your help is much appreciated.
 

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Discussion Starter · #16 ·
Well guys I have kind of found out why in the past I never had any problems with sealing an intake manifold on the coolant port area. The right stuff gasket maker that dries in like one minute will dry harder versus the regular Ultra black gasket maker. I noticed that even the 90 minute gasket maker stuff dries a bit softer versus the quickest drying right stuff maker and I am betting that with it drying so much harder that when it got cold out that the hardness of the right stuff would somehow break its seal and then allow that breakup to compromise the gasket and allow it to weep when it was cold and it would then re seal when hot as it expanded.

Just my two cents and noticed that while doing some research and also noticed that one little bead I put on top of the intake gasket sticking out that the 90 minute stuff was a lot softer feel to it versus the quick stuff that dries in one minute.

On the 90 minute stuff it says to get stuff bolted up within 5 minutes and only tighten the bolts finger tight to start to have the gasket maker push out and then wait an hour then let it cure and then torque things down. What I am thinking is using the regular 24 hour Ultra black on the coolant ports only and then use the 90 minute gasket maker only on the end rails and let it sit for and hour and then proceed to torque it to specs.

I like the quick gasket maker stuff that dries super fast but it has been my curse these last three times and don't want to use it again. In the past the older stuff has always worked for me and never any leaks like this. Why it has been this way I don't know but that is all I can figure out as when my 377 was built it was not used with right stuff one minute gasket maker but with Loctite brand RTV gasket maker that is like the 90 minute stuff and it never gave me any problems.
 

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Discussion Starter · #18 ·
Hey Bogie I read your post again about the using of grade 8 fasteners and about the washer etc. I have never seen to where you have to use this special bolt or that special bolt to have on an intake manifold. I have seen that ARP offers bolts etc but that would be over kill for just an intake. I am using grade 8 washers which I would think would be hard enough to stand up to what torque I am using and as far as them moving most of them I had to grind a little bit of a flat spot on them so I could get them on to lay flat.

Almost any intake bolt kit you buy will not even have that strong of a washer and I don't see how I am not getting enough torque on things but do recognize what your talking about the friction giving a false reading without something on the bolt to over do the friction and get a better torque reading. My question is what could I stick on the bolt head to reduce friction and what should I torque things to then since there is less friction? 25 ftlbs is the most I have done and in the past I have never used anything under the head of the bolt and the sealant on the bolt threads of what I used I would assume would help in a good torque reading. You got me thinking on this one and I don't want to risk anything stripping out as that is the last thing I need.
 

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I’m not trying to infer that there is a need to use grade 8 fasteners on the intake. The crux I’m trying to get at is the overall strength of the fastener needs to be balanced with the recommended torque.

My concern is you are receiving the recommendation of using higher strength fasteners and more torque. The danger in that especially with bare aluminum threads is pulling threads out of the casting. One needs to always consider that aluminum castings are for the same load area not as strong as cast iron thus you risk pulling the threads out of the casting and creating another problem.

Some years ago we went through a spate of people pulling threads out of castings including iron castings when using ARP fasteners with their recommended thread lube and torque recommendations. This seems to have settled down which might be either fewer people are reporting this issue or ARP changed some characteristic perhaps of the thread lube.

But pulling the threads out your head’s by increasing the torque load on the fasteners is a real possibility and my most fundamental concern is using extra force to correct what is likely to be a dimensional problem. The vast majority of us go not need to jump through hoops to get the intake to seal up around the coolant ports. This would suggest there are other problems going on.

- To that end this could be goofy torque readings on the fasteners.

- The lack of sealer not just thread lube on those fastener’s threads as they do usually penetrate into the coolant passages.

- Improper tightening sequence distorting the intake.

- Maybe the gasket.

- Possibly the mating angle top to bottom of the head’s or intake isn't right such that the gasket is not sufficiently crushed to form a seal.

- In a similar thought perhaps the length wise surface of either the head or the intake isn’t straight and flat, or maybe the head’s are fastened to the block creating an angular error with respect to the intake.

For the addition of sealer that should be on both sides of the mating surface on the gasket. Although I often use a light grease on these surfaces to aid in allowing movement of the assembled parts to move over the gasket surface as the fasteners are torqued and prevent gasket from sticking when the castings are separated to reduce to eliminate clean up.

The fact that there is leakage at the ends leads my to think this is a dimensional problem of the parts. Not that goo of some sort can’t solve the leak but the root cause is a bad surface mate for some yet unknown reason.

My caution is that if fastener torque is good then more is better approach brings the risk of pulling threads out of the relatively soft aluminum compared to the steel fastener. That adds problems rather than fixing them.

Bogie
 

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Discussion Starter · #20 ·
I get you on that one Bogie so should I step down to a grade 5 bolt instead of using the grade 8 bolts and still follow the recommended torque of 25 ftlbs that Edelbrock calls for while using sealant on the bolt threads? I always use RTV on the bolt threads and they have always sealed and never caused any problems of themselves. When I did check things all seemed good as before I put my intake on it was fine with a straight edge. Before sealing the intake it was laid down on the cylinder heads with no gaskets and as far as looking things over it looked good and fit good and flat across the entire head surface area of what you could see.

Now all things considered the heads had no problems sealing with grade 8 bolts and washers and lock washers using Loctite gasket maker on the previous 377 Dart shp build which was decked to the exact same dimensions and never any problems with it. Same head gaskets were used and felpro 1205 gaskets. Now on to the 350 SHP build using the Right stuff quick dry gasket maker since day one had been the only different thing and this has been a problem with two different intakes both brand new and checked out good.

I doubt the heads would have any problems from being fine one time then another all of a sudden not want to seal as the back ports since they don't flow through never seem to be the problem but only on the front and that stubborn passenger side more then any other. It was fine for several weeks and several heat cycles and kept torque on the bolts and no problems and then just one warm day of 70 degrees then down to zero windchill without ever running my truck the intake gasket decides to leak.

The gasket maker never cured right the last few times it was done like it should have and to me that is in my hunch the issue is coming from and it drys harder versus regular RTV but that is just an opinion and not saying I am right. I don't want to risk over torquing things and I know opinions will vary on that but in the past I have always done no more then 25 and it has always worked and checked torque afterwards and it gave me no problems.
 
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