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Highest HP on Stock bolts???

2K views 21 replies 17 participants last post by  jsf350 
#1 ·
Whats the highest HP that has been recorded with stock (non-retorqued) head bolts???

Also give tuning info if avail.

I am curious as to how well these things actually work, so far I have been very impressed, give your thoughts!!!
 
#7 ·
A lot of it comes down to the amount of timing being added and drive pressures. When drive pressure starts to sky rocket, head gaskets don't last long. If your seeing a good amount of boost 55psi or more it is just extra insurance
 
#11 ·
Was just reading the new diesel world the other day, they said over 400 horse power or around 40 psi of boost and you need studs. My truck has been running around 450 or more for around a year and an sps 62 running around 35 to 40 psi and no problems so far. A friend of mine has made around 580 on stock bolts with an htt 64 and he hasnt had any problems either.
 
#14 ·
got a friend running 650 with stock studs/head. Boost to 60psi.
 
#16 ·
i know a guy that hits 70+ psi daily with 62/71 twins
 
#18 ·
damn you made that kind of numbers with a 62:shock:

that gives me hope:headbang:
 
#19 ·
So what is a safe torque number on the stock bolt? 125? 150?

Any special procedure or just start at the center and work out?:confused013:
 
#20 · (Edited)
from 05 service manual for removed head

WARNING: THE OUTSIDE EDGE OF THE HEAD
GASKET IS VERY SHARP. WHEN HANDLING THE
NEW HEAD GASKET, USE CARE NOT TO INJURE
YOURSELF.
1. Install a new gasket with the part number side up,
and locate the gasket over the dowel sleeves.
2. Using an engine lifting crane, lower the cylinder
head onto the engine.
3. Lightly lubricate head bolts with engine oil and
install. Using the sequence shown in , tighten bolts
in the following steps:
a. Torque bolts to 70 N·m (52 ft. lbs.)
b. Back off 360 degrees in sequence
c. Torque bolts to 105 N·m (77 ft. lbs.)
d. Re-check all bolts to 105 N·m (77 ft. lbs.)
e. Tighten all bolts an additional 1⁄4 turn (90°)



torque starting at center working your way out
 
#21 ·
id take them out one at a time 'n lube threads before torquin. asked same question a while back and got same response. prob wont hurt anything to just start torquin in sequence but it surely wont hurt to go the extra 10 min route and lube threads before torquin. . .only way to know you're maximizing your chances of accurate torquin.
 
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