need some help

[bartlett_drifter]

ok- i keep blowing my HG's. hahaha what a real shocker. i just did it with an HKS metal gasket and ARP's. I just dont think it likes to rev a lot. what im trying to figure out is how to further prevent this from happening. im also trying to figure out an reliable setup to drift on makeing around 375rwhp.








shaeff edited for clarity.

 

[kwnate]

Did you prep the head and block before you torqued it down? If you didn't thats your hg problem...

 

[89turbotoy]

yeah you need to have the head and block machined before you put in a new hg.

 

[Yellow 13]

Go 1JZ lol.

 

[BJ91T]

Use punctuation,correct spelling and grammer and that should solve your problems.

 

[Disced]

lol, likes to rev a lot?

You sir... There is really no word to explain you.

 

[Sawbladz]

okokok i keep blowing my hgs hahaha what a real shocker i know but i just did it with an HKS metal gasket and arps. I just dont think it likes to rev alot. what im trying to figure out is how to further prevent this from happening. im also trying to figure out an reliable setup to drift on makeing around 375rwhp.

Hahahahaha. "I did MHG and ARP...my engine will be perfect now...Yay" :nono:

No. Go read. Comprehend the reading. Act on the reading. Repeat until results are satisfactory.:biglaugh:

 

[bartlett_drifter]

hahaha awesome for the bs i didnt know this was an english test. i had the block and head machined and as soon as i started to play wit the car i blew the new gasket.

 

[shaeff]

hahaha awesome for the bs i didnt know this was an english test. i had the block and head machined and as soon as i started to play wit the car i blew the new gasket.

Disclaimer:

it's not an english test. nobody says you need to speak or type perfect english. however, if i read a post and i cannot understand what point is trying to be made, i'm more likely just to skip it rather than trying to help the person figure it out.

i edited your first post so that it would be more easily comprehended by the masses. keep the run-on sentences to a minimum, and try using some punctuation. that will get a LOT more people to help you.

there are some exceptions, but i doubt this is one of them. /Disclaimer

now, what exactly happened when you "started to play with it"? were you beating on it? just driving it? what were the head bolts/studs torqued to? are you sure the machinest had a smooth enough finish on it?

a mildly modded 7mgte will make 375bhp pretty easily. but you can't just slap a turbo on and boost it up. you must have the supporting modifications in order to take advantage of every setup. pushing 15psi on the stock turbo isn't going to do you much good when your old fuel pump decides it wants to give up the ghost.

enough speculation on my part. the ball is in your court.

-shaeff

 

[rumptis]

with MHG...if you have things preped right and torque down correctly it shouldn't blow unless you do something really stupid.

You may have had it machined but was it smooth enough...most shops don't do a good enough job for a MHG.

 

[jdub]

Ok...so, you like to rev a lot. How about some specifics:

- When your block/head was decked, was the RA spec (smoothness) 30 RA or less?

- How much material was removed from the block and head? What thickness HKS MHG did you use?

- Did you torque your ARP hardware to spec? 75 ft/lbs for bolts; 81 ft/lbs for studs using the TRSM torque pattern...both assume using moly for lube on the hardware.

- What boost are you running? How are you controlling boost?

- What fuel mods have you done if any?

Read this before you ask a question...follow what it says and you will get a good answer.
http://www.supramania.com/forums/showthread.php?t=20163

 

[bartlett_drifter]

The guy that did the machine work for me does mostly engine work on race motors and I have never heard anything bad about him before. I was told to torque the studs to around 85ftlbs by a guy that built a 700+ hp 7m. After we put the motor in and broke it in I turned the boost up to 14psi and we did a street tune using an hks super afr and digital ignition. I took the car out one night to a local drift spot and started to beat up on it. Everything was going great and after about 15mins of drifting it suddenly started blowing a cloud of white smoke. We towed the car home and i cheked the motor and the gasket was blown again. The only reason im annoying yall wit something like this is bc its my third turbo supra that ive built the motor for, and ive never had this much of a problem whit a head gasket before.

 

[jdub]

Sounds like the machine work is at fault to me. 85 ft/lbs is fine (not that different from the ARP 81 ft/lb spec), as long as moly was used to lube the studs. If this machinist does not have experience w/ a 7M and he used motor oil (like a lot of old schoolers will) that is not near enough torque...the ARP spec for studs using motor oil is 105 ft/lbs...not even close. Also, if he did not pay attention to the HKS RA spec (30 RA) for that MHG (I assume a bead type) and get the block/head deck smooth enough...that will cause a problem too. One other thing on the MHG...if he used copper spray on a new MHG, it will deteriorate the factory viton coating which can cause a problem with the initial seal.

Regardless if this machinist does race motors or not...if he is used to doing domestic engines and does not pay attention to the tight tolerances required on a 7M, you are going to have problems. Also, after at least 5 heat cycles, you should have done a re-torque on your ARP studs.

14 psi of boost should not blow a MHG...that is unless you allowed it to go lean and experienced detonation. If that happened, there is not MHG out there that can take abuse like that for very long. Do you have a wideband O2 to monitor your AFR's? To do a decent "street tune", a wideband O2 and EGT gauge is just about mandatory.

 

[bartlett_drifter]

I know we didnt copper coat it and i used the molly lube and im not 100% sure on the machine work all i know is that he is supposed to know what hes doing. ill ask him about his specs on it tho. To tune it i used the Innovate lm1 wit the aux box and i works really well so unless something happened that it didnt record im pretty sure there was no detonation. Im fixing to tear the motor down and send the head off to toyota just to be safe this time.

 

[starscream5000]

Did you have the backing plate thing (forget the name of it) bolted to the block when it was machined? That could be your culprit right there . That, and/or improper RA spec and wrong torque pattern used...

 

[bartlett_drifter]

Wen i droped off the block it was completely bare and i know i torqued it with the right pattern. The only thing im not sure about is the RA spec. The only thin i can think of is that he might not have machined it right wich is why this time im going to send it to toyota. Thanks for everyones hep but if it blows again im just going to get a new engine.

 

[starscream5000]

If the block was "completely bare" then I'd say there was no rear timing plate on it. That plate has to be machined with the block or when the head is bolted down that becomes the high point on an otherwise flat surface . That is most likely why you have BHG.

 

[bartlett_drifter]

Awesome, Thanks starscream!

 

[starscream5000]

No problem . Take you block be to the machinist and make sure the head didn't warp when it BHG'd. And while you're having the rear timing cover machined, go ahead and check the RA specs whith your machinist to ensure that they are below 30. Try to have him get them lower than 25-20 if at all possible. The lower the RA spec, the better the seal with a MHG .