Photos below are of a 454 head. I have a problem with the intake gasket not sealing between my head and the tunnel ram manifold I have. The pictures below are after 6,000 miles of driving. Oil consumption as you might imagine was poor, and after a 30 minute hot soak, tons of blue oil would appear on start up. I had always thought it was valve guides or seals, but it appears the culprit is the lack of a seal between the two components. After these photos were taken, we installed new gaskets and valve seals. Two hundred miles later, the problem has returned. The 454 block was flat so it wasn't shaved. On a prior rebuild years ago, the head was surfaced. I would imagine that as the head now sits lower, the gap would increase between the head and the tunnel ram. Looking for a solution to the issue, but would also like your comments on these two ideas: 1. Remove the intake and s****e off existing gasket material. Loosen the head bolts and then on re***embly, tighten the tunnel ram to the heads first, and then tighten the head bolts. 2. Locate a thicker intake gasket - which I haven't been able to find. Thanks for any suggestions you may have.
Thanks for the prompt reply. Running a Fel Pro FPP-1037 .039 currently. Not wanting to lower my compression though. Are there thicker intake gaskets available? Brand? Currently using this one: Fel-Pro FPP-1211
You can't loosen the heads and expect that they'll pull inward and seal to the intake. The heads are each located by two dowel pins pressed into the block deck so they won't shift off of their proper location. You should be able to mill the bottom surface of the intake to get it to sit lower and seal up to the heads. Thicker intake gaskets are another solution, I would contact a few of the major suppliers of aftermarket parts (Jeg's, Summit Racing, etc.) to see if the gaskets you need are available. You could always buy some gasket material of the correct thickness and make your own.
Well, just found this one.... .120 thick vs. the original which is .60 http://www.summitracing.com/parts/FEL-12755/ I think I'll give this a shot. Thanks for steering me away from option number 1.
Good deal you found some. I kinda thought thicker intake gaskets should be available too, but in all honestly its been so long since I looked into specialty gaskets, I wasn't sure what was out there, but definitely knew head gaskets came in a few ranges.
Completely overlooked it when ordering them this last time. Love the performance of the car after the rebuild, but just had this setback. Easy fix if it all works out. Thanks!
The deck on the block may be near stock dimension, but I'd bet that tunnel ram was milled at some point. Usually the gap between the intake and the block at the ends tells you something. If a thick gasket works, great, easy, if not milling or welding and milling the intake might be required. Good luck.
Check the manifold with a straight edge first. Set the manifold on the block without the gaskets and check the fit, intake gaskets are approx. .062 and .120 thick. Use feeler gauges or peices of old gaskets on the corners to check the fit and use silicone for the end gaskets. The photo looks like the manifold was not flat or was over tightened. Hope this will help.
Greg - unsure of the history of the tunnel ram. I've owned the car for 13 years now, and not sure if the previous owner ever had touched the surfaces. I'll include some photos of how it sits right now and a few of it turned upside down when it was off recently. Mustang - glad to see a T Bucket owner respond. That is what I'm driving. Driver's side - front It takes a pretty healthy shot of Ultra Black to seal the gap at the ends. P*** side - front Overall Installation Not sure if any of these photos give an idea if it has been surfaced or not along the way. I have always wanted to know the manufacturer of the tunnel ram. It looks like this number might give away the age of the casting - 1985. Any idea of who CR may be?
How do the bolts line up while bolting the intake on, off a little ? I had the same problem with a sbc, the heads were milled but the intake was stock. I had the intake milled and the problem was gone, your feeler gage will show a bigger gap at the bottom mating surface than the top if that's the case.
Swade - not an issue to bolt up this last time, but once we get the intake and gasket material off, we need to look specifically at the gap like you and the others are bringing up. Appreciate the reply!
1971 - thanks for the tip! Searched that combo on the web and found one that matches the top half of mine (model number 1985 vs. the 1984 in the thread. Looks like the guys that had mine before I did, ground off all of the ID markings when it was polished. Thanks!
Just a quick question, your not using RTV on the main part of the gasket, right? I'm sure you are aware that gas disolves RTV and only a sealer such as Permatex #1 or #2 is fuel resistant. Just checking....
Hard to tell from the photos, but the p*** side front one looks like the intake isnt parallel to the head. As somebody said, I'd set the manifold on, no gaskets, shim it .060 on all four corners by intake bolt holes, and check the gap at the bottom of mating surface. If its not the same it needs an angle mill. The rail end gaps arent big. Id still try the .120 gasket idea once before spending money at the machine shop. Shim it to .120 and see. Good luck.
Have the same prob. w/ sb manifold, Idoubt you'll be able to use 120 thick gskt w,o further milling, will be too much gskt. the orange residue around ports looks like permatex,just a guess. thier is a tutorial on how to ck manifold/head interface over on "hotrodder's . com." might want to do a search over there . dave
Looks like you tried to overtighten the intake bolts to stop a leak. MAKE sure you torque them in sequence and DO NOT overtighten them. The manifold looks warped adjacent to the center bolt hole. Clean the manifold down to metal and check it very carefully with a short straightedge and a flashlight around the bolt holes.
Guys, Thanks for all of the tips! @2old - Could have been Permatex. That was about 12 years ago, so not sure if we used it or not back then. When the rebuild happened this last time in February none was used. Guess we should knowing the situation I have. @Greg - thanks for the tip on how to check the clearances. I'll also look for the threat that 2old mentioned on Hot Rodders. @Rick - I polished the tunnel ram surfaces to the point of being glossy. Maybe went too far as there wasn't any texture left. Had to do it to get rid of a lot of the corroded areas around the water jacket. I haven't really had any noticeable leakage to worry about giving the bolts an extra tug to try and stop a vacuum leak or water issue. Will do on checking the flatness of the head and the tunnel ram. Back to 2Old or anyone who would like to reply - It would seem that if the gasket is just a bit to thin on the lower half and not on the upper, that the extra thickness would do the trick. Trying to think (without actually doing it) about what happens with two thicker gaskets in terms of it not fitting. Would it cause the manifold to sit too high and then not have the proper mating surface to the openings and bolt holes? My hope is that if the top half is too tight it will just compress the gasket more than the bottom. You have me wondering though.... Getting anxious to try this out - may not wait to after the car shows on the 16/17 weekend to see what I can find out. Trouble is, if the manifold does need to be milled, I doubt that I would get it back in time. Gaskets should arrive by Wednesday so we'll see. Thanks again everyone!
Yeg, here's a way to see where your at ,fitment -wise. most 3/8 flat washers are about .o6o" thick, take 4 of those,glue to 4 bolt holes in head ,set your man. in place, check clearence. this will give a close approximation of standard gskt thickness, then double up those washers and see how much that pushes up the manifold, you'll be surprised, that's the approximate height of a .120' gskt. dave
@2old - that is a great tip to do before I rip open the packaging on the gaskets and find out they won't work. Can't wait to try this out. I'm curious about one other thing. The car is flying fast after the rebuild. No driveability issues at all with the exception of the blue smoke on startup after a hot soak. Engine vacuum is at 12". Knowing I have a small leak at the bottom of about 4 cylinders, what happens to the vacuum level after it's plugged? Will it drop? We were pretty surprised to see how high it was once we threw a gauge on it. I'm planning on throwing in some 55 power valves while this is all apart, but started to think I may need to wait and see what the vacuum level is after everything is sealed up. Will a leak to the oil galley area cause a measurable change in vacuum? And if the leak was a large one (more than I currently have) which direction would it affect vacuum - increase or decrease it? Thanks!
Plug the leak = increase the vac {probably only slightly}. may want to check valve guides/seals [oil puff on startup] also,if engine was running well,why change pv? if it aint broke y'know dave
Dave - The plugs are wet with fuel. Really went up on the jet sizing last year hoping that it would help to cool the engine down. That was when the block was a 396 with the 454 heads - blocked coolant p***ages. The engine is now essentially new, so going to drop the jets two numbers at a whack, and get the PV in line with the usual guideline of 1/2 vacuum level. When cold and just getting into it a bit there is a flutter, so hoping that with the change from the current 3.5's to 5.5's, it will take care of it. Easy enough to change back if it makes the problem worse. I have .37 squirters which really helped with a bog last year - again a different engine configuration. I think the flutter is after the initial squirt, so we'll see what happens. Actually loving getting into the tinkering side of this. Stroking the 454, finally having heads that match the block, a 3000 torque converter (that works) and a hydraulic roller cam has really made this a fun combination. The car is way too fast for me to drive and just short spurts of 1/2 throttle are a real kick in the pants. I'm sure you would put your foot in it and have a ball, but in street conditions, the acceleration spooks me. Just need to get rid of the embarr***ing oil smoke on start up (new seals were installed and the guides were fine) so I think the manifold issue will solve my ills and I'll have a fun summer ahead. I think I'm going to pull it apart tonight and get it done before I head out of town this weekend. Curiousity is killing this cat!
Another bit I forgot to mention, felpro only has the sealing bead on 1 side of the gskt., mr. gskt ultra seals have it on both sides. thought I'd p*** that along. dave
Interesting. My neighbor who helps me with the engine work, had a spare paper composite gasket that he said was pretty cheap, and it looked like it would have been a much better fit overall than the Felpro. He only had one, so we skipped using it. Knowing that we were putting on the same exact gasket that leaked before (the first photos in the thread), the hope was that proper installation would have cured the problem. Obviously not, or so it seems so far. I truly believe that if I just have a little more thickness this problem will go away and whatever mismatch there is with the head to manifold will be minimized to the point the leak won't occur. But before we ****on it all up, we'll check to make sure that we don't have a problem here. He was questioning the manifold when we put it on last time, so we'll see if .120 will do the trick. I take it the one side of the sealing bead goes toward the manifold correct? That is how we had it before.
Uh oh. Just received the gaskets and they don't have the bolt hole (notch) between the intake ports. Good thing I only removed the carbs and didn't destroy the existing gasket. I know you can't see it, and Summit just shows a generic picture (Felpro 1275-5), but is notching the gasket a standard practice? I see that Mr. Gasket offers a .120 with the notch (#110) . Half price with some notes about trim to fit even though the dimensions are pretty close to Felpro. Both series of gaskets do not have bead seals on this type of gasket - maybe the .120 size has something to do with it. Take a shot on an answer? Notch the Felpro or order the Mr. Gaskets?
Well, pulled the intake off tonight and what was expected I found. The gaskets were allowing oil almost freely to get ****ed into the intakes. The valves are a goopy mess, but at least the mess is soft. No plans to pull the heads until summer is over, so if it doesn't burn off, then we'll clean them up later. I wasn't able to get good photos of what was going on, but maybe you can tell by looking at the blue sealing surface if there was much contact at all. Starting with 1&3 with flash 5&7 with flash 2&4 with flash 6&8 with flash Overhead Hopefully those all in the correct order. Trying to get the valves Needless to say this long standing problem of 10 years or more - my engine has always burned a lot of oil, has come to this area of the engine - not rings or valve seals or guides. A leak down test turned out very positive prior to removing the intake so good news there. No time to get the manifold milled, but we'll take a look at the fit using the shimming ideas that were mentioned. What a mess for only 200 miles. Good thing we didn't wait for another 200. Comment away if you can see some tell tale signs on the gasket surface as to what is or is not happening here. Should the blue be smashed indicating a tight fit? Thanks!
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