I just installed a new rpm air gap intake manifold, a few days ago, did the rtv along the front and back edge, but there is oil leaking from the back edge, ive taken intake manifold off again, there's seems to be pletty of sealant there, but the oil seems to come underneath it, the seal was loose, the front rtv seal was stuck down nice and solid, so oil seems to be slipping underneath, so is there a fix for this??

dave

 

you have to make sure the surfaces are very clean. Use some thinner on a rag and scrub it well

 

I had this same problem with my new engine build. I did a few searches on here and saw some people talking about a sealer called The Right Stuff. I went ahead and dropped 20 bucks on the can from jegs, little pricey, but so far no rear manifold leak.

I think mine messed up when I tried to hook my pcv to the air cleaner. There wasn't enough vacuum there to pull the gases out so I think they found the weakest seal first. Make sure at least 1 pcv is installed and working properly. I should have checked here first because I found threads saying not to do the air cleaner thing.

Also make sure when you reseal it everything is clean back there. There are little holes in the block in that rear seal area that can collect oil. Be sure to brake clean/carb clean those holes and blow them out with an air hose before reapplying your rtv and overlap the very edges of the manifold gasket.

 

You sure have had a bunch of problems with the top end of this engine.Intake leaks and oil leaks-have the heads been milled too much?Below is a link to a pic of possible PCV issues-In the pic the PCV system is open and wont build up pressure-have you changed or modified it?

http://s206.photobucket.com/albums/b...t=DSC00138.jpg

 

Theres the reason for your low vacuum and at least one of the one of the reasons it was running so badly.

You have to do it over again.
What part number/brand gasket did you use and how much torque? There is also a sequence to tighten the bolts.

Here are the instructions.
http://static.summitracing.com/globa...s/edl-7501.pdf

 

the pcv is now plugged into the big pipe coming out the back of my holley.

 

yeah followed the bolt tighten sequence, I used the fel pro gasket seal kit, it was the one recommended on the edelbrock website, 25lb/ft of torque

do you use rtv on the bolts?

do you glue or use RTV under the gaskets along the heads??

On my cylinder heads, there's a port in the middle, but on the airgap intake, there isnt a middle port, does that matter??

cheers

dave

 

Yes, you need to put a little RTV on the bolts.
The port on the heads is for the heat crossover and you dont need it.

Dave, please take some pictures of the top of the engine before you put the intake back on. Some pics of where you said in a different post that some porting was done on the heads.

Can you still read the stamped number on the pad on the front passenger side of the block or has it been machined off?

 

Did you leave the open breather on the opposite valve cover?The reason I ask is you dont want too much pressure in your crankcase and not too much vacuum either.

 

I'm sure you've checked but just in case make sure there's vacuum present at this connection.

 

yeah that breather is still there

cheers

 

good point!, I will check it now

cheers

 

yep, I take photo's for u., need to look for a number

cheers

 

It will be on the front pass side above the water pump.

 

follow link to get pics



the number reads ,"T6S525013" and then "V0610LK", the last number is very hard to make out


cheers

dave

 

1-chase all your head threads with a 3/8-16 tap
2-clean the threads with a drying spray like starter fluid, throttle body cleaner, electrical contact cleaner or similar.
3-Scrape all the old gasket residue off with razor blades and clean and dissolve with lacquer thinner or acetone.
4-Before installing gaskets, make sure all surfaces are oil free and dry
5-Use a very little rtv or any non hardening thread sealer on intake bolts. The end holes on each head are blind so not needed there. Caution, too long of bolts here can interfere with some pushrods.
6-Use rtv sparingly around the water ports on heads before the gasket on the heads and also on the gasket surface to the intake. Use very little. I wipe it on and then tap my finger on the rtv to keep it minimal
7-Don't use the supplied end rubber gaskets. Put a healthy bead at least 1/4" high on the end surface.

With the rtv you must work fairly quickly to ensure it doesn't skim over before you set manifold.
You should let it dry 24hrs before starting engine. RTV totally cures solid in 72 hrs. Any excess can be cut off with a razor on the outside after setting up. The inside excess will not fall off if it has been allowed to cure before running engine. Usually heads that have been off at one time have been shaven at least a little to straighten, and that will make the oem end gaskets to thick, they will squeeze out and leak, even over time.

With an intake that does not have the exhaust crossover, no extra detail there is required.
Match the intake gasket to the intake manifold to make sure it matches and seals all the ports. Some oem gaskets will not seal the larger aftermarket intake ports completely and you will have vacuum leaks.(popping thru carb etc, sound familiar?).

Lastly, make sure you have a working pcv to prevent crankcase pressure and resulting oil leaks. With no pcv working, YOU WILL HAVE OIL LEAKS.



Stainless 304 crossover blockoff if required.

 

New problem found!, one of the bolts for the intake, was longer than the rest, abit odd I thought!, got the intake back on again, tighten up bolts! and guess what!??, the long one wont tighten up, just keeps on spinning, so bubbe'sr been at in the past, its 2nd in from the passager side front, could I get away with it for now, or new cylinder heads needed?? and some new cams at the same time!! lol

cheers

dave

 

Thats good Dave
I didnt really care what the numbers were.... I just wanted to make sure that they were still there so now we know that the block has not been decked.
___________________

Noonie, Excellent tutorial!

Dave, if you follow Nonnie's instructions exactly, you will be fine.
Dont forget to let it sit over night before you start the engine so the RTV can cure up some.

 

Sorry but based on those pics of yours, slapping on an intake and carb is not gonna make that thing any faster!! Maybe you have more up to date pics than those, that black pipe plumbing...hope it is was from the last guy. Loosen a few rockers and pull the lifters and check the face of them for scoring and wear. I'd bet the cam is toast also. Change the timing set (gears/chain) yet? Looks rode hard and put away wet.

Before starting, degrease (sanitize) with something that evaporates without a residue. Some leave a oily residue from the propellant in the can. RTV will not seal to surfaces with this residue. Typical brake clean or electrical clean works correctly.

Intake sealing:
Use an oil rated RTV - typical blue is not the best. Most of the "Ultra" black or grey are for oil and are used by OEM's. The bead shown above is typical but over lap the tri-corners (block/intake/head joint) a little more. Sealer at the ports is only required on used parts with corrosion pitting. Couple dabs of adhesive or RTV to hold in place is all that's needed gaskets themselves.

Intake bolts:
Run a light bead down the threads, strip from top to bottom of thread portion only. If you put it on the tip only all it will do is wad up at the first thread and do nothing.

Finally be sure to use pcv on one side and breather or vent line back to air cleaner on the other side. Crankcase PSI will push that RTV bead out everytime.

Hope that helps,
Later.

 

sounds like you may need to repair the threads with something like a "heli-coil"
didn't say if heads were CI or AL (i see CI now), but doesn't matter much if stripped.
it will run if you ignore the problem, but is not proper . . .