Need help with a overheating issue. out of ideas...

[Idealsupra]

for the record....if using a hks mhg then i agree with all above statements...because the RA is so small.

however if you use a cometic gasket , you can simply resurface the head, and straightedge the block to make sure its not warped, if its not then you can clean it up VERY well with razors and brake cleaner and some fine grit sandpaper.... and the cometic should seal fine.

ive done numerous like this and have had zero problems.

 

[foreverpsycotic]

like ideal said, get a cometic or titan(believe its a copy)

BTW nice rabbit, i came from VWs as well, i had one older (73 bug) and one newer (92 golf)

 

[jdub]

Ideal - I have to disagree. The Cometic 50 RA spec applies to both sealing surfaces...the head AND block. I have also seen several Cometics blow within a few weeks because of what you suggested doing...it's a shortcut I personally will not take. I'd use a stock HG before I did that

Do it right, do it once!

 

[theKnifeArtist]

i like your rabbit. what year is that?

 

[Idealsupra]

Ideal - I have to disagree. The Cometic 50 RA spec applies to both sealing surfaces...the head AND block. I have also seen several Cometics blow within a few weeks because of what you suggested doing...it's a shortcut I personally will not take. I'd use a stock HG before I did that

Do it right, do it once!

to be honest if it blew....it was because the block wasnt done properly or a section was missed etc...

cometic will seal against the block fine if its prepped 100% and is straightedged and not warped at all....also pitting in the block is a big concern as well...so that could have been the case.

im not talking about stock applications either..... ive put them on like that and they have held fine with over 20psi of boost.

i will say that if you HAVE the option of the time and the LOT of extra money it takes to do it..then yes i would pull the block and disassemble it and have it decked also.... but IMO with the cometics with correct block prep they shouldnt have a problem sealing.

 

[theKnifeArtist]

dont mean to hijack..but its kind of on topic..i remember seeing a thread somewhere where it listed all the tools needed for a HG job, and i cant find it in the search cuz im buried in BHG threads, also, what gaskets should be replaced during a hg job..any help?

edit.
nevermind, im gonna start a thread.

 

[jdub]

Ideal - you're correct...the one I've seen were not done properly. They:

resurfaced the head, and straightedge the block to make sure its not warped, if its not then you can clean it up VERY well with razors and brake cleaner and some fine grit sandpaper.

Completely ignored the Cometic RA spec...sorry man, but I just don't buy it. You can come up with all kinds of reasons why the Cometic blew...the real reason is the RA spec for the block was not met. Cometic puts out a smoothness spec for their MHG's for a reason...ignore it and you do so at your own peril. You might get away with it (like you have), but IMO you've been lucky

If you're going to leave the block in the car, the answer is simple...use a stock HG and torque it down with ARP hardware to ARP spec. If you can't prep the head AND block for a MHG...don't do it.

 

[IJ.]

Did it ever get a retorque?

 

[Idealsupra]

Ideal - you're correct...the one I've seen were not done properly. They:



Completely ignored the Cometic RA spec...sorry man, but I just don't buy it. You can come up with all kinds of reasons why the Cometic blew...the real reason is the RA spec for the block was not met. Cometic puts out a smoothness spec for their MHG's for a reason...ignore it and you do so at your own peril. You might get away with it (like you have), but IMO you've been lucky

If you're going to leave the block in the car, the answer is simple...use a stock HG and torque it down with ARP hardware to ARP spec. If you can't prep the head AND block for a MHG...don't do it.

i have to admit i :biglaugh: to your first comment lol.....

i guess we will agree to disagree.....if the block isnt pitted, and is cleaned up VERY well.... and is checked for warpage and passes.... you shouldnt have a problem with the cometics. the aluminum head will warp and distort a HELL of a lot more then a cast iron block due to the bhg conditions...i ALWAYS have the head resurfaced....but if theres no pitting on the block ive done over 20 cars like this and none of them have blown...

i do agree with you though...the 100% RIGHT way would be to deck the block as well. i would never put a hks gasket on without decking the block...but i feel 100% comfortable doing a cometic.

 

[Subcept]

i like your rabbit. what year is that?

'84, I put some more pics / info on this thread http://www.supramania.com/forums/showthread.php?t=40753&page=2


I almost have the head off, need to get that big hex wrench on monday, then I'll see what I got to work with. 2 broken old vacuum lines so far, and it had a fair amount of oil coming out of the turbo, coating all the tubing / intake.

one of the exhaust mani studs was cross threaded in, and took all the threads with it when I finally got it out. argh.