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383 engine tapping and oil burning- weird

10K views 15 replies 4 participants last post by  RowShan 
#1 ·
Well I have some issues that I mentioned in a previous topic I had going but wanted to make the title correct in this one. I got a 383 stroker off a lady that is seperated from he husband and she kept the engine it has
has 400 crank, PRW Roller rockers-1.5, mild to med cam, stock heads, with headers, and edelbrock 1405 600cfm carb. Thats all I have found out so far since I wasn't around when it was built.

First thing is I have is a nice tapping/ticking noise-sounds like its coming from the top end, I really only notice it when its at a slightly high idle.. or when I rev it up and its coming down off the rev I can hear it loudest coming down/ I removed the valve covers to see if anything looked broken, First I took off the drivers side and it looked good then I took off the pass side- it looked good except for one thing! On the pass side- I think #6 exhaust rocker. On top of the rocker is a bolt going into it, unlike all others that have a nice Alan screw. Could this be not letting it be tighten down enough? Another thing I noticed and it may be completely normal.. is when I felt all of the rods I could twist all of them except for one towards the back, (still talking about pass side). Should only one have pressure? Or are a few of them really loose?

The next issue I have noticed is on the #1 cyl, header tube it just starts smoking a little, nothing has been spilled or dripped on it, it almost seems as if theres oil burning inside of it?? is that possible? I checked my oil level with the dipstick and it actually looks a little high.. could the level being too high make oil come out of weird places?

Any help would be greatly appreciated! :confused:
Thanks.
Rowland
 
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#2 ·
I would say that your ticking is from the loose rocker arms. I had a very similar situation on mine after break in..

I'm not familiar with those rockers but you should have more than one that's tight at any given time. Get a diagram and rocker tightening sequence and retighten your rocker arms. I would also guess that the one with a bolt is strangely out of place. Depending on what type of Allen bolt it is, go to your hardware store and see if you can get a replacement like the others. Replace that bolt and retighten everything back down to spec.

The oil burning could be lots of things. I have no idea how oil burning inside of a header tube would smoke on the outside. Where is the smoke coming from? From the flange or lower on the tube? If it's the flange, you may have an exhaust leak, which can also make a ticking noise... What color is the smoke? Do you have black smoke in the exhaust as well?
 
#3 · (Edited)
yaaaa duh, i dont know how oil on the inside could smoke either.. lol
but its actualy a few inches down on the header tube.. it just starts smoking for no real reason after it warms up.
It doesnt make any black smoke, and the exhaust at the tailpipes is normal, smells a little rich but dosent smoke unless it sits for a few weeks and then I start it..
 
#4 · (Edited)
Are you sure there's nothing dripping on the header? Does the smoke have a color or smell? Antifreeze will smell somewhat sweet and be white, and oil will have a bitter smell that's black. I've had both and will never forget the smells!

The coolant leak was actually a small crack in the cylinder head between the water jacket and the header bolt. It leaked just enough out to cause it to smoke and be a PITA. I "fixed" it by filling the bolt hole with black silicone and then shoving the bolt in and letting it cure for a couple days before I fired it up.

Take a real close look at the area around your header bolts for #1. See if the gasket is wet right there or if there is anything collecting. Start it and look just at those bolts until it starts smoking and see if you can catch it dripping.

There has to be something dripping on it, the trick is just figuring it out! Good luck and let us know what you find!

EDIT: Are your rockers full rocker or just roller tip?
 
#5 ·
Ill check it, in a few. Thanks but it is actually on the bend of the header tube which is out and away from the engine so if something did drip I sont think it could hit out there... but Ill watch it real close. But I'm not sure about the rockers I know their PRW 350 3/8 1.5 thats whats stamped on them..
 
#6 ·
Do your rockers look like this, just roller tip:


Or these, which are full rocker:


Can you wiggle the pushrod under the rocker arm? That would be what's causing your tapping noise. The bolt probably doesn't have a locknut on it so it's loosening up and allowing your rocker to slap around... As for the polylock, I would get a new one. You're probably not going to find one at the hardware store as I suggested before. I know summit sells extra polylocks for the other manufacturers, so probably check with prw to see if they'll sell you extra ones. I don't see them on their website but I would imagine they will.

There's got to be something on those headers already or dripping on it anyways... Let me know what you find!

Here's a pretty good writeup on adjusting the valve lash that I stole from another post on here:

What is Hydraulic Lifter Preload?

Mechanical cam designs require a running clearance or valve lash, while hydraulic lifters are just the opposite. When the rocker arm assembly is properly torqued down into position, the pushrod must take up all the clearance and descend into the hydraulic lifter, causing the pushrod seat to move down by .020" to .060". The distance that the pushrod seat moves down away from the retaining lock is the "Lifter Preload". The hydraulic mechanism requires this precise amount of "preload" for it to do its job properly. See figure below.



What happens if the amount of Hydraulic Lifter Preload is wrong?

If clearance exists between the pushrod and the seat in the hydraulic lifter, after the rocker arm assembly has been torqued down, you will have no lifter preload. In this case the valve train will be noisy when the engine is running. All of the hydraulic force produced by the lifter will be exerted against the lifter's retaining lock, and this could cause the lock to fail. If the opposite occurs and the pushrod descends too far (more than .060"), then you have excessive lifter preload. In theory, a hydraulic lifter can pump up whatever preload you put into it.

Therefore with excessive preload, as the engine RPM and oil pressure increases, the hydraulic mechanism will pump-up the pushrod seat. This will cause the valve to be open longer and the lift to be higher. This will decrease the cylinder pressure, lowering the performance of the engine. If the preload is excessive it may cause "backfiring" from the engine. How to correct this situation will be explained in the next sections.

When rebuilding an engine, what can cause Lifter Preload to change?

Almost anything can affect lifter preload. If you do a valve job, surface the block or heads, change the head gasket thickness, or buy a new camshaft, the amount of preload can be affected. Sometimes these changes cancel one another out and your preload stays the same; this is more by luck than design. This is why you must always inspect the amount of preload the lifter has when reassembling the engine and be sure that it is correct.

Fast and Easy Way to Check Hydraulic Lifter Preload when using Non-Adjustable Rocker Arms

With the cam, hydraulic lifters and pushrods in place, install your rocker arm assembly. Use the prescribed method in your repair manual and torque down all the valve train bolts in the proper sequence. Pick a cylinder that you are going to check. Hand rotate the engine in its normal direction of rotation until both valves are closed. You are on the compression cycle for that cylinder. (At this position the valve springs are at their least amount of tension making the job a little easier to do.)

Wait a few minutes, allowing the lifters to bleed down. Now, lay a rigid straightedge across the cylinder head, supporting it on the surface of the head where the valve cover gasket would go. Using a metal scribe and the straightedge, carefully scribe a line on both pushrods. Now carefully remove the torque from all valve train bolts, removing any pressure from the pushrods. Wait a few minutes for the pushrod seat in the hydraulic lifter to move back to the neutral position. Carefully scribe a new line on both pushrods.

Measure the distance between the two scribe marks, it represents the amount of lifter preload. If the lines are .020" to .060" apart you have proper lifter preload. If the lines are the same or less than .020" apart you have no, or insufficient, preload. If the lines are further apart than .060", you have excessive lifter preload. To bring your preload into tolerance, use one of the methods described in the next section if necessary, or call the Crane Tech Line for assistance (904/258-6174).

Methods to Adjust for Proper Hydraulic Lifter Preload

There are several different methods for increasing or decreasing the amount of lifter preload, depending on valve train design and how the rocker arm is held onto the cylinder head. Keep in mind that the automotive manufacturers have made changes to the valve train over the years. What may work on one year's engine may not work for another, even though they are basically the same engine. There is one method that universally works on all these engines, change the pushrod length!

Use a longer pushrod to increase preload, a shorter to reduce preload. Crane offers various length pushrods, and offers custom length pushrods. Many methods are illustrated throughout the catalog, here are a few of them: Custom length pushrods Bottleneck stud shims Bridge mount rocker arm shims Pedestal mount rocker arm shims Adjustable pushrods Conversion rocker arm studs "Kool Nut" adjusting nuts Guideplate and rocker arm conversion kits Adjustable rocker arms (both stud and shaft mounted) Replacement guideplates and studs

Using Adjustable Rocker Arms to set Hydraulic Lifter Preload

The easiest method to arrive at proper lifter preload is when you have an engine with "Adjustable Valve Train". Unfortunately, since 1967 most domestic engines, with the exception of small and big block Chevrolets, have been made with non-adjustable rocker arms. The Crane Catalog shows you several ways of converting your engine to an adjustable rocker arm system. The following sections will describe how to set the preload with adjustable rocker arms.

Hydraulic Lifters Can Be Adjusted at Any Engine Temperature

Since hydraulic lifters can compensate for thermal expansion of the engine, the adjusting can be done with the engine cold; hot adjustment is not necessary.



Adjusting Hydraulic Lifters for Proper Preload

In order to adjust the preload, the lifter must be properly located on the base circle or "Heel" of the lobe.

At this position the valve is closed and there is no lift taking place. You will need to watch the movement of the valves to determine which lifter is properly positioned for adjusting.

1. Remove the valve covers, and pick a cylinder that you are going to set the preload on.

2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe, the correct position for adjusting the intake.)

3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.)

4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at "Zero Lash". Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly.

5. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close .Whenitisalmostclosed,stopand adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm.

6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again.

Do Hydraulic Lifters Need to be Primed with Oil?

Many people mistakenly believe that hydraulic lifters must be soaked in oil overnight and be hand pumped up with a pushrod before installing into a new engine, however this is not necessary. In fact, this could cause the lifter to act as a "solid" and prevent obtaining proper preload. What is very necessary is the priming of the entire engine's oil system before starting up a new engine for the first time. This is done by turning the oil pump with a drill motor to force oil throughout the entire engine. Crane Cams offers oil pump primers for Chevrolet and Ford engines.

Mechanical Lifters

All pushrod engines using mechanical (solid) lifters, or mechanical roller lifters, must have an adjustable valve train so that precise adjustment for "Valve Lash" can be made to match the camshaft's requirements. Valve lash is the running clearance that exists between the tip of the valve stem and the valves mating surface of the rocker arm. (It is expressed in the Crane Catalog as "Valve Lash" and on the camshaft specification card as "Valve Setting". Both terms mean the same thing.)

The amount of valve lash can vary between camshaft profile designs, being as small as .010" on some and as great as .035" on others. It is important to use the recommended valve lash when you first test the performance of the engine. You must also be concerned with thermal expansion of the engine components. (This is especially true if using aluminum alloy cylinder heads, or block.)


Compensating for a Cold Engine when Adjusting Valve Lash

When installing a new cam, the engine will be cold but the lash specifications are for a hot engine. What are you to do? There is a correction factor that can be used to get close. We mentioned that the alloy of the engine parts can be affected by thermal expansion in different ways, therefore the amount of correction factor to the lash setting depends on whether the cylinder heads and block are made out of cast iron or aluminum.

You can take the "hot" setting given to you in the catalog or cam specification card and alter it by the following amount to get a "cold" lash setting.

With iron block and iron heads, add .002"
With iron block and aluminum heads, subtract .006".
With both aluminum block and heads, subtract .012".
Remember this correction adjustment is approximate and is only meant to get you close for the initial start up of the engine. After the engine is warmed up to its proper operating temperature range, you must go back and reset all the valves to the proper "hot" valve lash settings.

Setting Valve Lash on Mechanical Cams

All the valves must be set individually and only when the lifter is properly located on the base circle of the lobe. At this position the valve is closed and there is no lift taking place. How will you know when the valve you are adjusting is in the proper position with the lifter on the base circle of the cam? This can be accomplished by watching the movement of the valves.

1. When the engine is hot (at operating temperature) remove the valve covers and pick the cylinder that you are going to adjust.

2. Hand turn the engine in its normal direction of rotation while watching the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake valve. (Why? Because when the exhaust is just beginning to open, the intake lifter will be on the base circle of the lobe, so the intake is the one we can now adjust.)

3. Use a feeler gauge, set to the correct valve lash, and place it between the tip of the valve stem and rocker arm. Adjust until you arrive at the proper setting and lock the adjuster in place.

4. After the intake valve has been adjusted, continue to rotate the engine, watching that same intake valve. The intake valve will go to full lift and then begin to close. When the intake is almost closed, stop and adjust the exhaust valve on that particular cylinder. (Again, when we see the intake valve almost closed, we are sure that the exhaust lifter is on the base circle of the lobe.) Use the feeler gauge and follow the procedure described before in step 3.

5. Both valves on this cylinder are now adjusted, so move to your next cylinder and follow the same procedure again. In the future you may find shortcuts to this method, but it still remains the best way to do the job correctly.

Using Valve Lash to Help Tune the Engine

The engine only responds to the actual movement of the valves. Since the valve cannot move until all the running clearance (valve lash) has been taken up, the amount of valve lash you use affects the engine's performance. For example, if you decrease the amount of (hot) valve lash, the valve will open slightly sooner, lift higher, and close later. This makes the camshaft look bigger to the engine, because of a slight increase of actual running duration and lift. If you increase the amount of (hot) lash the opposite occurs. The valve will open later, lift less, and close sooner.

This shows the engine a smaller cam with slightly less actual running duration and lift. You can use this method on a trial basis to see what the engine responds to and keep the setting that works the best. Just remember, the more lash you run, the noisier the valve train will be. If the clearance is excessive it can be harsh on the other valve train components. Therefore, for prolonged running of the engine we do not recommend increasing the amount of hot lash by more than +.004" from the recommended setting. Nor do we recommend decreasing the hot lash by more than -.008".

Warning:

"Tight Lash" camshafts cannot deviate from the recommended hot lash setting by more than +.002" increase, or -.004" decrease. "Tight Lash" cams are those which have recommended valve settings of only .010", .012", or .014" on the specification card. These lobe designs have very short clearance ramps and cannot tolerate any increase in the recommended valve lash. The extra clearance can cause severe damage to valve train components.

With "Tight Lash" cams, we recommend using only the prescribed amount of hot valve lash, and that close inspection of the engine be maintained. Please realize that changing valve lash settings from the recommended design specifications will change the harmonic characteristics of the valve train, possibly causing valve spring deterioration and breakage.
 
#7 ·
WOWWW Thank you I am very supprised that someone would take that much time to help me out!! But my rockers are identical to the Blue prw ones mine say 3/8 1.5 on them. I just went to our local performance shop and they had some of the new polylocks or wherever there called. So later today I wll pull the covers back off and do what i can. I haven't got a chance to do anything yet today, been a busy mornign with work, but Thanks again!!! :thumbup:
Ill watch the header tube real close when I start it up
 
#8 ·
I have adjusted the roller rockers and it is still making the tick/tock noise. It isn't coming from the rockers, their all quiet! The sound is not as fast as the valve train, its more like the cam/crank speed. I couldn't hear the noise from the bottom end untill I removed the torque converter cover, now I can hear it down there. Also I wanted to mention that the noise isn't present when at idle or high(over 3000) rps, it will only make the noise when its coming off a rev or if I hold it at about 2000 rpms, Kinda weird. I can't figure this out??? Also I dont think it makes the tocking noise when I put it in gear, only park or neutral.. Any more ideas?? Please throw some ideas my way.
Also i found that there was some oil leaking from the valve covers and I replaced the gaskets and that seems to of fixed that!
 
#14 · (Edited)
Thanks lngliv3, I'm hoping thats not it seeing how the engine has barely 1,200 miles on it.. But I guess it could be.. One thing I just noticed is that If I put a long screwdriver between the flywheel and the engine block there is some forwards and backwards play! Could that mean a bolt is loose? and it could make a ticking/tocking noise? Also there is some oil that looks like it could be coming from the rear main.. its hard to tell though i can just see it dripping off the bottom of the oil pan all the way to the back... Could all of this be related?
 
#15 · (Edited)
RowShan said:
Thanks lngliv3, I'm hoping thats not it seeing how the engine has barely 1,200 miles on it.. But I guess it could be.. One thing I just noticed is that If I put a long screwdriver between the flywheel and the engine block there is some forwards and backwards play! Could that mean a bolt is loose? and it could make a ticking/tocking noise? Also there is some oil that looks like it could be coming from the rear main.. its hard to tell though i can just see it dripping off the bottom of the oil pan all the way to the back... Could all of this be related?
There should be no real discernable play at this point. Total endplay of the crankshaft assembly into the block is less than .010", barely noticable by eye. If the flexplate moves more than this something is wrong.
 
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