HONEST Head bolt torque

Projectmk3

Projectmk3

1988 hard top N\A
Jun 20, 2007
44
0
0
41
Ontario
I have an 88 supra hard top N/A, i rebuilt the motor after i spun the bearing on the #3 rod, then after break in i did it again (perhaps due to the fact i run my car really hard) no it knocks and about a week ago i said screw the 240000mile motor i got now, I'm going JDM. I have only enough money for the motor and oil nothing else (ARP blots)

I'm getting a 7m-ge with about 45000 to 50000 on it and was wondering if A. should i re-touque? and B. how many Ft.lbs.?

I'm using stock bolts that are on the motor, and i want to know who has personally done 72lbs. ON STOCK BOLTS...Cause to me 55ft.lbs. to 72ft.lbs. is a big jump, i don't want to strip\break bolts on new motor...Please HELP
 
supramacist

supramacist

Banned
Apr 8, 2006
1,501
0
0
The Grassy Knole
Well your 45/50 thousand mile spec is all bull shit. The company that threw that engine together from a grave yard old parts is only guessing at how many miles it has on it from the scrap they put it together with.

JDM engines are not plug and play. It doesn't arrive and get put right in. It has to be completely rebuilt. What they do is is pull a bunch of parts from a bunch of engines that are shit and put it together.. If you have 240k on your engine this is a good idea. But not without a rebuild. And you don't have money for arp hardware and you haven't even said you would concider buying stock oem head bolts from toyota wich is the minimum you should do.

You have no idea what you are about to get into. My advice to you is do some hardcore research. Cause you are screwed either way. Something is getting rebuilt. If you have a half a cent worth of sense in your head.
 
Projectmk3

Projectmk3

1988 hard top N\A
Jun 20, 2007
44
0
0
41
Ontario
Thanks jack :) just wanted to make sure...and as far as plug and play engines, i have helped friends do the same, buy it and drop it in, only once did my buddy drop a valve in a zc twin cam on start up, but that 1 out of like 15 motor swaps
and its a honda...the motor has a 60 day 3000 mile warranty im not to worried, its from engine trend in riverside, good rep
 
M

Merlyn

New Member
Mar 9, 2007
162
0
0
Maryland
We torqued my stock bolts to 88 ft lbs using extensions (which loses some of the torque) and they all (even the some what stripped ones) managed to not brake in the least
 
CRE

CRE

7M-GE + MAFT Pro + T = :D
Oct 24, 2005
3,485
0
0
Denver, CO
If you're reusing the bolts the car came with at least measure them to make sure they're alright. Personally, I wouldn't go 72lbs on 20yo head bolts, maybe mid to upper 60's. As long as they're within specs though you should be fine.
 
I

iwannadie

New Member
Jul 28, 2006
981
0
0
gilbert, az
If your going through all the hassle why not drop 70 bucks on some new ARP bolts? At least youll have some piece of mind with knowing they arent 20 years old and stretched.
 
Projectmk3

Projectmk3

1988 hard top N\A
Jun 20, 2007
44
0
0
41
Ontario
My buddy had a good point, i i were to torque the bolts down without changing the head gasket, wont it mess it up? do i have to worry about it?
 
BlackDynamite

BlackDynamite

KTHXBIA
Feb 24, 2007
714
0
16
Oregon
make sure to do the bolts in order too ;]...Lol...I just got through with my rebuild and i have a metal head gasket...77 ft/pounds of torque on arp head bolts.....If you get that engine i would defiantly recommend, just like supramacist said, a complete rebuild....Also check the crankshaft, for the Troublesome 6m crank, if you have it, and get the 7m crank...especially if you're low on the money and you run your car hard...the 6m will spin the number 3 bearing, and others mostly number 3, because it doesn't have counterweights on the number 3 and number 5 if correct.......mine was spun on number 3....check out my rebuild in my sig........It should help out a little bit at least...:]
 
I

IJ.

Grumpy Old Man
Mar 30, 2005
38,728
0
0
62
I come from a land down under
Wow......

If they're the Original Bolts and Haven't been pulled down to 11ty7 ft/lbs by Bubba the Merkanik how on earth would they be "stretched" or in any way damaged after being pulled down to 55 ft/lbs?

This is not even close to their Yield zone.......
 
suprabad

suprabad

Coitus Non Circum
Jul 12, 2005
1,796
0
0
Down Like A Clown Charley Brown
IJ. said:
Wow......

If they're the Original Bolts and Haven't been pulled down to 11ty7 ft/lbs by Bubba the Merkanik how on earth would they be "stretched" or in any way damaged after being pulled down to 55 ft/lbs?

This is not even close to their Yield zone.......
Click to expand...

I've done many head gaskets and re-torque's, and I always bring em up gradually and in sequence to 82lbs w/ stock bolts (engine dead cold of course). If it's a rebuild or a new head gasket, I re-torque them after about 5or 6 heat cycles, never had a bolt failure.

I'm not saying that you can't buy stronger bolts, but what I am saying is that IMHO stock toyota head bolts get a bad rap, and are way under-rated.

Also fwiw, I hate it when guys speak in absolutes. I have personally purchased very good condition jdm motors and transmissions, so this shit about "all jdm's are junk and definitely have to be rebuilt" is simply not true.



:3d_frown:
 
Last edited:
starscream5000

starscream5000

Senior VIP Member
Aug 23, 2006
6,359
0
36
Hot and Humid, KY
suprra_girl said:
can we have some further explanation on this "troublesome 6m crank"??? all of our 86-89s have the 6m crank and... well they seem fine, cept when idjits run em out of oil etc but what's so troublesome, seems like a new myth to me ;)
Click to expand...


You stole the words right out of my mouth ;). There's nothing troublesome about a 6M crank, it just doesn't rev as smoothly as the 7M crank due to no counterweights on the #2 and #5 cylinders :3d_frown:
 
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