O-ringed block

[vorsberg]

I recently bought a "crate engine" from a -86 GN.
Actually it came in several boxes, the block is said to be bored and honed with a torque block.
The bores look OK , I plan to lightly hone them and replace the rings on the Speed Pro forged pistons.
Whats the proper ring gap for the rings ?
The block is o-ringed (but not the heads) the copper gaskets are missing,where do I find new ones ?
Or perhaps to play it safe, whitch stock type gasket can I use instead ?
I´d rather change the headgaskets than driving over my crankshaft.....

 

[dank GN]

You can get gaskets from SCE gaskets

 

[TurboCrazy]

I think I read somewhere that someone measured the width & depth of the o-ring groove. Then got copper wire about the same size(maybe slightly over sized), & gently tapped that down into the o-ring groove. This filled the o-ring groove, & allowed the use of the gasket of choice.

 

[dank GN]

http://scegaskets.com/wp-content/uploads/2014/02/O-Ring-Instructions.pdf

 

[TurboCrazy]

Dank, good info if you want to use the o-ring grooves in the block as intended. I was under the impression that the OP was looking for a way to use the block without dealing with the o-rings or decking the block to get rid of the o-ring grooves? If this is not the case, then ignore my previous post.

 

[dank GN]

Well I don’t think you can if the groves are in the block . I personally wouldn’t o ring the block because then you are stuck . I had a set of heads that I was able to weld up the o ring groves then deck the filler metal . With a block I wouldn’t think you could do that but I could be wrong

The pics where before I re surfaced them btw

 

[vorsberg]

Dank, thanks I found SCE gaskets at Summit Racing but the closest size was 3,850 in. cyl dia. My block is + .030
but I guess they will work ? The o-rings in the block looks like stainless steel so perhaps the easiest way is to use the SCE gaskets as I rather not deck the block again ( I´l check it for straightness ) The heads were ported so I `l cc them.
I`m building this motor for E-85 as all gas stations here in Sweden got it,I was thinking 20 psi for fun in the streets and 25 psi at the strip. What would be a suitable CR for that motor ?

 

[turbo89]

Dank, thanks I found SCE gaskets at Summit Racing but the closest size was 3,850 in. cyl dia. My block is + .030
but I guess they will work ? The o-rings in the block looks like stainless steel so perhaps the easiest way is to use the SCE gaskets as I rather not deck the block again ( I´l check it for straightness ) The heads were ported so I `l cc them.
I`m building this motor for E-85 as all gas stations here in Sweden got it,I was thinking 20 psi for fun in the streets and 25 psi at the strip. What would be a suitable CR for that motor ?

you can also run a Graphite Head gasket if the block is oringed ... done this many many times and will hold more power than most can use.
Its very common to ORING the block and not the head... method works very well.

20 psi on E85 is a waste... CR depends on a lot of things .. what heads, what cam etc .. need to evaluate what your goals are

 

[TurboCrazy]

turbo89- That is good information to know! In the past I have passed on a couple different really good deals on blocks, because they were o-ringed & I didn't want to mess the o-ring thing. Oh well, I plenty of stage blocks anyway. I did the o-ringed heads back when it was the thing. It worked, but I thought it was a PITA also.

 

[dank GN]

Dank, thanks I found SCE gaskets at Summit Racing but the closest size was 3,850 in. cyl dia. My block is + .030
but I guess they will work ? The o-rings in the block looks like stainless steel so perhaps the easiest way is to use the SCE gaskets as I rather not deck the block again ( I´l check it for straightness ) The heads were ported so I `l cc them.
I`m building this motor for E-85 as all gas stations here in Sweden got it,I was thinking 20 psi for fun in the streets and 25 psi at the strip. What would be a suitable CR for that motor ?

If you are just running e85 all the time . Then a 10:1 motor would be really responsive on the street. I’m running 10.5:1 on e85 btw

 

[TurboBuRick]

I would machine it out.

 

[0-60n4]

It's been many years so I do remember the exact details, but I tried the O-ring block method on my 297 cu. in. stroker Typhoon engine and could never get it to hold up. Ended up going with a head gasket. I don't remember exactly what my engine builder ended up doing with the grooves but I don't think it was machining the block down. May have used some copper wire but for some reason I seem to think maybe they were filled with Devcon liquid metal (which is great stuff). I actually had a Honda motorcycle (1000 interceptor) that cracked the block and Honda told the dealership to repair it with Devcon and they would warranty the repair for life. Never had another problem with it. It can be used to build up a damaged shaft and machined back down. So keep that in mind as an option.