roller cam vs Hyd. flat tapper cam
Well, I learned something new yesterday that scared the living heck out of me...I bought the Lunati 60101LK cam for my rv that I plan on replacing the motor in...It appears that I lost some cam lobes with the missing I hear in the old motor, as well as blowing smoke out the tail pipes (175,000miles+)...I lost oil pressure last year and as a bandaid, I replaced the oil pump with a new HV melling...That did not correct the problem with low oil pressure once warmed up...
This past Feb. after traveling about 500 miles round trip, I heard a dreaded knocking sound that reminded me of a rod knock, but it sounded much higher and perhaps piston slap, or a piston pin knocking...Either way, it disappeared when I drove it 5 hrs later about 2 min. after starting it...It reappeared the next day when restarting it at a Auto Zone with a tech at hand, then disappeared after the 2nd heard knock...The tech agreed that it might be a piston, since the sound was near the top of a motor...
Either way, yesterday I learned that all of today's oil has limited zinc and other anti-friction additives in them and this is the sole reason why 1 in 10 motors upon break in fail~! This is according to Joe Gibbs racing...According to his site, if a person uses his breakin oil, they would have a better chance of a 1 in 40 chance of a hyd. flat tappet cam wiping out...
Although the odds are better, after reading his information and with the fact that I travel a lot in my Rv, I do not think it wise to go with a Hyd, flat tappet cam anymore, since I would have to have an oil after break in with high amounts of zinc, phosphorus and sulfur and low amounts of Calcium, which Calcium is a detergent used in today's oil... It is Calcium that washes away the anti-friction additives in oil and leaves the metal bare, causing extreme wear of the cam lobes....This is unacceptable in a pre-roller cam motor...
I would be curious how many people have already lost their motors because of this...Mine took 2 years for the lobes to wipe, now the motor is junk...
So, currently I am looking at two cams, one by Howards and the other by Lunati...I think Howards is going to be the winner for a Hyd. roller cam...
Any thoughts on this oil dilemma from the school of hard knocks and how it tore up your motor and learning about the additives being taken out of the oil you used?
I understand that at the end of 2011, they took most, or all of the zinc out of the oils currently on the shelves at your local big box stores, as well as big box auto parts stores...all because they wanted Cat converters to last 125,000 miles, or more and that zinc coated over time the platinum in the converters which then were either replaced, or illegally removed permanently.
Yep ... we have had many discussions on this subject, and your post pretty much sums it all up.
There are now many companies selling "Classic Motor Oil"
Classic Car Motor Oil
Collector Automobile Engine Oils (camoils) These guys are from Calgary, and the oil is bottled by Boss Lubricants. We stock it inour store ... but sadly, it's still a hard sale to make.
Sometimes the school of hard knocks (pun intended) is the only thing that will make people believe. :(
Do a search here, you'll be overwhelmed...
I'm actually glad I was lucky enuf to learn this last night when I was searching for a motor oil to break the motor in with....If it wasn't for the internet and all of this instant knowledge and networking, such as this site, lord knows how many more motors would be lunched...
I would love to tear my old motor apart after I get the new motor in, just to see the oil galleys and how much they are clogged up with what used to be my CAM LOBES~! :drunk:
Lastly, I did my homework prior to this post and viewed several war stories on what to use for motor oil, but they were dated around 2008 and earlier, so with the advent of 2011 and the oil company's again reducing the anti-wear additives to min, or none, made me wonder how many still do not know about modern oils and the demise of pre-86 motors due to the lack of anti-ware additives....
Thanks for all that replied, so far...And hopefully, to the uninformed, like me prior to yesterday, just maybe one motor can be saved before it is too late.
Excellent point in regards to reading OLD information.
Using RotellaT 15w40 diesel oil (SH) *used to be* a viable work-around, before they legislated the required use of catastrophic converters on diesel engines too.
For me, since I have not build a motor since the late 80's after suffering a stroke at the early age of 37, then again in the year 2000, this is going to be my first build since then...How much has changed, overall~! So, it is only prudent that I take Inspector1's advice and use the same cam he recommended since it is very close to the Lunati 60101LK cam that I currently bought...
Here is the thread I am referring to:
I can't take the chance of wiping a lobe with the lunati cam, since being a disabled vet on a 70% pension..It has taken since Feb. to get all of the parts that I currently have for the motor build...I still have to get a new GM shortblock and an oil pump and now the roller camshaft, lifters and new cam chain cover and various bolts to secure new water pump, fuel pump, fuel pump push rod etc....$2,100.00+ so far....
Thanks for your input and your reply...
we're using flat tappet solids in our jersey skiff motors. As long as you are using a racing oil with zinc in it, like the Joe Gibbs or Brad Penn you are ok. Folow break in procedures with extra zinc, and either 1.3 rockers or remove inner springs and you should be good. I m building one now that will include 1.6 rockers and a Mike Jones cam.
Being with limited funds does not allow a mistake happening in a build with the chance of wiped lobes on a new motor, it is not an option!
So, as in the Army, the motto of : KEEP IT SIMPLE FOR STUPID, really applies here in my situation...With the added cost of a roller, vs the cost/RISK of wiping out cam lobes (HYD. Flat tappet cam) and having to re-pull the block, then rebuilding the block a 2nd time and the added cost of the oil, bearings, cam and lifters and maintenance (cost of oil and filter changes every 400 miles, according to Joe Gibbs?), of a flat tappet hyd. cam- it is prudent for me to install the Howards retro roller cam CL110235-12, and avoid all the hassles of break-in and mental anguish from possible loss of my investment altogether...Moreover, the added cost of filter changes at 400 miles + the cost of specialty oils...( this is according to the Joe Gibbs web site...I travel on average 3000 miles to max 5,000 miles during the winter/spring months in this RV....At the cost of gas and oil, I can't do that kind of maintenance....
Mind you, I am currently stranded in Mesa, Arizona at a friends house and I can't move the RV due to the motor being FUBAR...Therefore, I have one chance at doing this right, so that I can get back on the road and back home...( thank god for friends)..The whole purpose of this motor build, is that the original motor was only 185hp. It ran well in it's early life, but could never pull a hill (Arizona mountains) even with 4.09 rear gears in the GM 14 bolt floater rear end...By over building the motor with the parts I have chosen, my TQ figures should be well over 400# and around 330-350 hp...That with a new GM Performance 12605117 short block, this combo with SUM-151124 vortec heads should last me the rest of my life, since I am almost 60, now.
Either-way, thanks for your input. But with the knowledge I now have Hyd. flat tappet cams are no longer an option...Wish I would have learned this dilemma 2 mths ago when I started buying parts...
Justnget a zinc additive when you putnoil in it. Its like $5 i think? I used autozone 10w-30 and a bottle of zinc additive for years and never had a problem.
In all my years of experience, I stayed away from roller cams, because of the simplicity of Hyd. flat tappet cams and them basically being maintenance free...
So, with the springs I currently have, which are Comp Cams 981 springs which are rated 100# closed and 370# open and these are on SUM-151124, vortec heads, which were made by Dart with the Summit name on them...They claim they are good to .520 lift and for comparison here is the cam that I bought for my build.
Cam Style Hydraulic flat tappet
Basic Operating RPM Range 1,000-5,500
Intake Duration at 050 inch Lift 213
Exhaust Duration at 050 inch Lift 219
Duration at 050 inch Lift 213 int./219 exh.
Advertised Intake Duration 256
Advertised Exhaust Duration 262
Advertised Duration 256 int./262 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.454 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.468 in.
Valve Lift with Factory Rocker Arm Ratio 0.454 int./0.468 exh.
Lobe Separation (degrees) 112
My question is, will these springs work with either of these Howard's retro fit cams:
Cam Style Hydraulic roller tappet
Basic Operating RPM Range 1,000-5,000
Intake Duration at 050 inch Lift 213
Exhaust Duration at 050 inch Lift 217
Duration at 050 inch Lift 213 int./217 exh.
Advertised Intake Duration 266
Advertised Exhaust Duration 270
Advertised Duration 266 int./270 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.485 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.495 in.
Valve Lift with Factory Rocker Arm Ratio 0.485 int./0.495 exh.
Lobe Separation (degrees) 112
Cam Style Hydraulic roller tappet
Basic Operating RPM Range 1,000-4,800
Intake Duration at 050 inch Lift 209
Exhaust Duration at 050 inch Lift 215
Duration at 050 inch Lift 209 int./215 exh.
Advertised Intake Duration 262
Advertised Exhaust Duration 268
Advertised Duration 262 int./268 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.465 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.470 in.
Valve Lift with Factory Rocker Arm Ratio 0.465 int./0.470 exh.
Lobe Separation (degrees) 110
Also what other things do I need outside of lifters? Will I need longer pushrods?
You will need shorter push rods.
-(retro) roller lifters are longer that flat tappets
You will need a reinforced timing cover and cam buttons.
-the lobes on a flat tappet cam are angled so that as it turns the pressure from the lifters pushes the cam backward in the engine. On a roller cam the lobes have to be completely flat to work with the rollers on the lifters. Hence the cam is free to walk or wander fore and aft. So you have to get "buttons" which shim the cam against the timing cover to keep it in place.
Also what ever cam you go with, you might as well get 1.6:1 rockers. This ratio tends to destroy the flat tappets, but rollers are perfectly happy. Hey its free power. Intake duration determines where the cam makes power (longer dur=upper rpm range power...lower dur=lower rpm range power), and lift determines how much power you make there. So if you get the 1.6:1 rockers, you don't change your power band, you just add more power to it. You have an RV, so lots of weight, you will need a cam with a lower intake duration. I based on the cams you have posted I would say you are in the ball park. I would also suggest a dual pattern cam (intake and exhaust duration are different). Typically for a factory head the exhaust doesn't flow as well as the intake, so cam makers compensate with a longer duration (or lift) on the exhaust valve. Someone posted the flow numbers for those heads of yours here a while back. Exhaust flow was pretty close (less than?) factory Vortecs, so again go with a dual pattern cam.
You might want to call a cam manufacturer and tell them what you are dealing with and they can help you pick a cam. I have been underwhelmed with Comp Cams phone support...have you tried this?
Thanks Silver Surfer for the fast reply...I was the person that posted the flow numbers on the Dart/Summit heads a couple weeks ago...I could not find any # on them, so I searched cached articles on the net and I finally found them..I chose these heads over vortec's because they were cheaper and a heavier casting than stock vortec heads..Moreover, since I do travel in mountainous country traversing from 800ft above sea lever to over 7,200ft, I figure this was the best option for worry free performance/cost....
I already have a cam button, but did not think about the difference in height with the lifters...Thanks, now I know~! I did try that program you mentioned, but I could not get it to work? Perhaps with all the security that I have on my laptop, something is blocking it...
Any recommendations on a re-enforced timing cover? I could always braze a small piece of steel to the inside of a stock cover...I did also pick up a new cast aluminum cover, but the part ordered wound up coming out of China...So, got to look for something better....
I do not think it wise to go with a Hyd, flat tappet cam anymore, since I would have to have an oil after break in with high amounts of zinc, phosphorus and sulfur and low amounts of Calcium, which Calcium is a detergent used in today's oil... It is Calcium that washes away the anti-friction additives in oil and leaves the metal bare, causing extreme wear of the cam lobes.http://www.infoocean.info/avatar4.jpg
That is correct...About 2 years ago, I started noticing a miss in my motor..I thought it was perhaps a plug, or wire, so I did a complete tune up. At first I thought I fixed it, but shortly after doing all this work and money, I noticed the miss was still there....I then had to replace valve cover gaskets and inspected the valve train and overall for the high mileage it did not look bad, so don't mess with it, if it is not broken...
What happened over that time is my oil pressure got so low, that I thought the pump went bad, so I replaced it with a hv pump and at first I thought it worked, but upon hitting the mountains and highways, I saw that anytime I hit a major incline, the pressure would drop to 10# or so....That is when I pulled one main bearing and replaced the rear seal at the same time, as well as the front seal...I inspected the bearing with plastigauge and it was OK...
So, I figured that it was time for a new motor, so here I am getting all the parts bought for a new motor install...I am still thinking about a reman. block, but out here in Arizona, there seems to be too many fly by night thief's..So I think it is safe to say that a new shortblock from GM is in order, as well as a roller cam....
Did you see this thread?
And this link was posted showing Mobile 1 15w-50 was intended for flat tappet?
Not sure how well a SBC will digest 15w-50 oil though. You do have other options for flat tappet specific oil though.
|All times are GMT -6. The time now is 08:53 AM.|
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.