PDA

View Full Version : Re-torque head studs?



S14_James
08-14-2005, 09:32 PM
Well I'm having a problem with missing coolant, the problem is I can't figure out where it is going, I have had my setup running and have put abotu 6000 miles on it. I have a fairly built S13 Sr with a cometic hg. Well lately I've been losing coolant the problem is I'm getting no signs of it in the oil and no signs in the cylinders. I'm getting low on coolant only when I go and boost a lot, I run 23-24 psi at high capacity. I'm going to run some more test tomorrow but I'm thinking I might need to check head stud torque, could I possible have to just re-torque them or am I just being stupid.
-James

BlackBomber
08-15-2005, 06:04 AM
Well I'm having a problem with missing coolant, the problem is I can't figure out where it is going, I have had my setup running and have put abotu 6000 miles on it. I have a fairly built S13 Sr with a cometic hg. Well lately I've been losing coolant the problem is I'm getting no signs of it in the oil and no signs in the cylinders. I'm getting low on coolant only when I go and boost a lot, I run 23-24 psi at high capacity. I'm going to run some more test tomorrow but I'm thinking I might need to check head stud torque, could I possible have to just re-torque them or am I just being stupid.
-James



I have read that it is common place to retorque after 1000 miles but I don't know of anyone who has really done that. What turbo are you using? 23-24psi is a good amount of boost pressure.

S14_James
08-15-2005, 06:56 AM
Greddy T67-25g
-James

Kingtal0n
08-15-2005, 04:34 PM
I had a problem with dissapearing coolant. it would just.. go away. no white smoke apparent, no dripping anywhere.

it was leaking into the car from the heater core, and the carpet was soaking it up.

----
2 weeks later, same sitation, but no more heater core!
It was leaking from the turbo water-inlet, dripping onto the turbo slowly and evaporating with nearly no smoke at all.

it is possible the coolant is leaking into the cylinders and burning slowly, especially if related to heavy boosting.. times when you cant see the white smoke coming out behind you. Have a friend drive behind you during boost and look for white smoke symptoms. then do a leakdown test on all cylinders to detect leaks into the cylinders, while doing the leakdown, open the radiator cap, and look for bubbles.
You can look for bubbles in the radiator with the motor running too, but it wont be as apparent.

cwdmark
08-15-2005, 09:24 PM
james, talked to matt downtown and he said it could be that you are pushing the turbo past its efficiency range, and at that high of a boost level it could be lifting the head. if i remember right at 21 psi you were making 450whp, and at a higher boost level you are making the same power... only with a lot higher torque.

makes a little sense... i think i was having the same problem, probably from running a little too much boost on pump, and stock headgasket.

S14_James
08-16-2005, 06:44 AM
Well you could say that but at 21 psi i made 450whp on dyno packs in ATL. Had to stop because the MAF was maxed out. I changed to the Z32 and I made 450 at 23-24psi on a in ground dyno jet in TN. I am pulling 4.75v on the Z32 when I'm doing that, and if i turn it up alittle I start to pull 4.85v I can't be sure but it seems to be picking up more power the whole way, it has been on the dyno the only thing holding me to these boost levels so far has been the MAF system maxing out.
I've got the boost down to 14 psi for the next few days to see what happens if it is just that then I shouldn't be seeing coolant loss. If not I'm going to be up for Friday so Matt can check it out.
-James

S14_James
08-16-2005, 05:51 PM
Well looks like it is not back pressure from the exhaust and my searches say I just need to torque them down to 85 ft lbs. I ran 14 psi today and same deal low on coolant and needed to bleed the head out again.
So I guess my question is do I need to get a new head gasket or should I just try and get the thing torqued down again.
-James

BandWagon240SX
08-16-2005, 06:28 PM
What kind of head Studs? ARP? I have ARP's on my Laser and I retorqued them after a few hundred miles and I havent had any headgasket issues at all running 22psi on pump gas. However when I retorqued the studs I do not believe they required any extra torque. My DSM also has lower compression (7.8:1)than the SR motor or KA-T.

Also, at least with DSM's, Cometic gaskets are very picky about block prep. The surface must be exceptionally smooth to get a proper seal. I'm afraid if its already pushing coolant that retorquing the studs won't help at all.

S14_James
08-16-2005, 07:47 PM
Well if everyone thinks that way i guess I need to get a new headgasket. I have a Cometic hg and arp studs. Anyone else have opinions and/or first hand knowledge let me know
-James

cwdmark
08-17-2005, 10:39 AM
how did you prep the head when installing head gasket? i just took mine to a machine shop to get resurfaced about an hour ago. had minor scratches around one of the cylinders.

i heard of people using scotchbrite but that leaves small grooves in the head. im just going to use some degreaser and a stone on the block.

Kingtal0n
08-17-2005, 12:08 PM
how did you prep the head when installing head gasket? i just took mine to a machine shop to get resurfaced about an hour ago. had minor scratches around one of the cylinders.

i heard of people using scotchbrite but that leaves small grooves in the head. im just going to use some degreaser and a stone on the block.



Brake cleen, razor blade, wire brush is how I do it. use brake cleen and the razor blade to scrape the surface of the head and block as clean as possible, continouselly wiping the crap you scrape off onto a towel. keep the surface wet with brake cleen as you scrape with the razor.

When you cant get any more off, very gently rough the surface with the wire brush in circle motions. Use motor oil while you do this to prevent scratches... and only do the block surface this way. dont use the wire brush on the head. This gives you a nice abrasive surface for the head gasket to grip on to the block. You will notice the old headgasket(s) leave behind an imprint in the aluminum, unless you shave the block (deck the block) those imprints will remain. Dont try using an electric wire wheel to remove them, the block surface will become un-even.

BEFORE:
http://i9.photobucket.com/albums/a90/kingtal0n/headwork/piston5.jpg

AFTER:
http://i9.photobucket.com/albums/a90/kingtal0n/headwork/piston9.jpg

jdm240witsr
08-18-2005, 09:51 PM
This is how it is suppose to look like.. machined the block AND head.

http://i7.photobucket.com/albums/y273/240witsr/deck.jpg
http://i7.photobucket.com/albums/y273/240witsr/IMAG0003.jpg

TheWolf
08-19-2005, 09:20 PM
I see this all the time with cometic headgaskets and other MLS gaskets. You probably do not have the correct surface finish on your block and head for proper sealing. A sub 50rA finish is required and can really only be produced by CBN, PCD and a really well well well maintained segmented stone. Lifting the head is not a problem. If you can feel any roughness in your head running your nail over the surface then its way to rough. Our heads come out like mirror finish.

S14_James
08-22-2005, 11:10 AM
Wouldn't I have had this problem before though? I've had the car running since March and only as of the last month I've been seeing this coolant thing come up. If it was due to surface finish then I would think the problem would have cropped up the first time I ran 21 psi back in March. If the headgasket is bad I'm going to pick up a Apex'i 1.1mm and another set of studs

-James