Guess what??...Another compression question!!!

:shrug: :bang:
Hi all, I ran into a very strange situation with my intake gaskets. My engine is freshly rebuilt with about 2,500 miles. It started running like crap so I tested the intake system with a smoke machine, sure enough there was a vacuum leak by the cyl. 2 runner. So I removed the intakes and found the gaskets absolutely destroyed, I never saw anything like that.

There were 4 runners with the gasket cracked opened at the top!!!!!!! I used # 1250 but used Gasgacinch glue from Edelbrook (A friend of mine suggested that he said to prevent leaks!!!) I should'n listen that advice:bang:

The other thing that happened before I found those vacuum leaks is that my coolant was overflowing out of my new Griffin radiator. I know that sounds like head gasket right?.. Well maybe it is. I have everything clean and ready to install my intakes back this time I'm going to us e gaskets # Felpro-1250-S3, they have a steel core in between plus ARP 12 pt intake studs. This time I'm going to place those gaskets dry only black RTV around the water ports and on the ends of the intake.

So just for my own peace of mind I did a compression test obviously with the engine stone cold because my intakes are off. Here are the numbers:
#1---170 #5---150
#2---170 #6---170
#3---170 #7---170
#4---170 #8---170

*Are those numbers normal for a 2500 miles or the rings will seal better within a few more K's miles increasing the compression:shrug: ?
*what happened to cyl #5? perhaps head gasket leak? Should I change head gaskets? (If so I will use FPP-1011-2 and ARP studs)

I have flat top forged pistons TFS H/C/I

I'm SOOO SORRY about the lenght of this post. It will be really appreciated all the ideas you guys can offer :hail2: :hail2: :hail2:

Thank you all, Nick
 
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Yes it was running fine but a coolant leak showed on my radiator when the lower corner hit the frame. I didn't notice that leak until I hear the coolant burbling after I shut the engine off. After it cooled down I refilled the system and started the engine with the rad. cap removed and saw the level drop I topped off again and as it reached normal temp. started pushing the coolant out.

Do you think it was somewhat overheating and the gasket got cracked? I have a mechanical temp gauge and never went over 190*.

If the gasket is starting leaking do guys think I should do both gaskets or only the one on the damaged side? How hard to will be to install the heads with the studs on the block? I heard many people complain saying that it is a b.....ch toinstall and remove the heads with the engine in the car. I have an SN95 brake booster.

Thank you for the reply and keep sending any other ideas.

Nick
 
alot of times those gasket get pulled down and on a aftermarket head with raised runners and thick decks they can cause this situation. As wired as it sounds i use alot of those junky Mr Gasket intake gaskets just because they are made with so much extra material around the ports. your # 5 might clear up get some heat in it and some more miles on it those #'s will post higher with heat and lube.
 
Thank you PUNISHER.... for your ideas I'll see how it goes this time. Tonight I found something interesting (I think).

I've been very suspicious about "what if a piece of the destroyed intake gasket came loose and got cought by the valve against the seat keeping the valve open enough to drop the compression in cylinder #5" I removed the intake valve spring and started rotating the valve. At first there was quite a bit of resistance like if something was stucked on the valve/seat faces.

After some spinning and tapping the valve was much easier to rotate pulling the valve against the seat, I put the spring back, adjusted the preload and re-ran the compression test on that cylinder. This time the compression showed 155 psi.
I then removed the the valve spring again and put a bit of oil on top of the valve inside the port and started spinning and tapping again for a while. At last I sprayed a bit of carb cleaner to remove the oil spinning and tapping the valve again until free of oil. spring back and tested...guess what???......I got 170 psi!!!!!

So that might was the problem or maybe the rings are not sealing enough and with the bit of oil raised my compression???? Well I'm going to take my chances and put everything back to see what happen. I'll post the results.

Thank you for the ideas but if there are more please post them.
My spirit is a bit high with those findings:D but only time will tell!!!

Nick
 
Overall your numbers look fine.

The added oil around the 'seal' could have helped in getting that extra 20 psi...

As long as you use the exact style gasket, you can just replace the potential "bad one."

You are being very patient and you will get this problem solved:nice:

Anyways, atleast it is a bump for you...