DVG73

I think I already know the answer to this but I guess I need some validation. Made some progress on the engine and actually installed it on the frame today. Thanks to Budman and Adam for the help. :cheers: Anyway, after basking in the glory and a few beers later, we notice that the head is not tight on the intake manifold rail. It appears to be tight on the cylinder deck but not where the head meets the intake rail. It looks like there is a 0.005 gap, which seems to me that it will be a leaker. It also appears that neither side is tight against the block or gasket for about a 1/2inch down from where the intake rail is. Is this an indication that the block deck needs surfacing (I know fatal mistake for not doing it in the first place) or is it a head issue, or both. The heads are new, never been used. Thoughts would be appreciated. Guess I know what I will be doing tomorrow, got to get more beer.


[Modified by DVG73, 9:07 AM 3/28/2004]

cardo0

All my intakes have a gasket face where the gasket seals it to head. I don't know what a intake rail is or looks like. Maybe the gasket and sealer produce a little spacing between head & intake but nothing should be loose . Now maybe the block had previous maching or even the intake could have machined. Scoggin Dickey (SCPC2000.com) sells intake gaskets in various thickness from 0.047" to 0.125". But try a thin feeler gage first and see how far into the lifter valley it will go - without using any force.
There are several methods/choices to seal the intake on the block & heads. I like to run a small silicone bead around the water passages (both sides of gasket) and a large 1/4"-3/8" bead on the block ridges that seal the intake to the block and keep the oil inside the lifter valley - no gaskets on block ridges. Also I use thread sealer on bolt threads and torque in a circular pattern from inside bolts first to outside bolts last. :thumbs:

DVG73

Guess I was not clear in my explaination. The gap is not where the intake sets but where the finger of the head gasket comes up to meet where the intake sets. I spent all day pulling what we did yesterday as well as diassembling the engine. Off to the machine shop for a deck surfacing. Learned a valuable lesson.

Budman68

TTT :cheers:

zwede

I think I understand what area you're talking about and no, there should absolutely not be a gap there. Must be incorrect surfacing of the block.

Fevre

Are you talking about the rubber gasket not extended from tab to tab? Does the tab extend to end of the head? If so I would look more to the rubber gasket as being the problem. You can go without the gasket, just use a bead of RTV between the tabs running across the block.

zwede

I think he's talking about the area between the head and block. The outer part of the head seals against the main block where the pistons are. Then you have a sealing surface on the inner part of the head, close to the intake. The headgaskets have "fingers" front and rear for this. He's talking about these fingers. Basically it sounds like the block was machined incorrectly where the heads are angled slightly down on the outer edge so the inner portion towards the intake is sticking up.

Atleast that's what I think he's saying. :)

Fevre

What's that old saying, a picture is worth a thousand words. :jester

DVG73

Thanks guys, you are right about the pics but my camera is 100 miles away at the moment. Never there when you need it. Markus is right, it is the area of the head that is away from the combustion surface on the intake side of the head. I talked with a machinst this morning and he said that this sometimes occurs (without machining) and that he knows some folks that just fill it with silicone and go on down the road (for how long is the question). Anyway, I am going to have the block decked, since there could be issues with leaking water or oil and possibly lost compression. I should have done it in the first place. Oh well, a valuable lesson learned. :banghead: It just gives Budman another opportunity to drink my beer.

Budman68

:smiliedrool: Someone say beer? :cheers: I think pulling it back out was the right decision.