Alright, so after a lot of blind optimism after breaking a FelPro head bolt, I finally decided to give in and get set of ARP's. I'm mainly asking this question because the amount of problems I've had were driving me nuts. I broke 2 separate bolts, first time it was the first bolt in sequence on the way to 65#, second time it was one of the lower bolts, the lower bolts turned excessively and only gradually raised toward 65#, and again one of the bolts snapped before even reaching it. (checked the torque rating of my wrench against 2 other wrenches, including an analog one, also checked the threads in the block, nothing.) As I said I'm buying a brand new set of ARP's so I'm hoping I'll have no more problems, I'm mainly asking for my own sanity. I am the only person I know that has had these problems and I've followed every direction to the T. Anyone have any clue why 2 brand new sets of FelPro bolts would break in different spots using Federal Mogul's instructions? o.0

P.S. I know I asked this question before, but now that I checked everything you guys suggested before I'm kind of wondering
if anyone has any other ideas. (i.e. If FelPro bolts are TTY, is it possible they stretch a tad much?) Thanks for the patience guys

 

did you check the felpro part number and make sure you had the right bolts?

 

IF the Felpro bolts were actually TTY, mispackaged or whatever, then the number 65# doesn't enter the picture at all. TTY bolts are designed to be torqued to a significantly lower number (22 ft lbs) and then turned a specific number of degrees of rotation (either 80° or 67° depending on the length of the bolt) in order to reach the appropriate stretch. (Reference Shoebox's website <http://shbox.com/ci/head_assy.jpg>.) Twenty-two pounds plus 67 degrees for TTY is not equal to 65# on an analog wrench. It may exert a similar amount of clamping force but the bolt is not designed to be torqued to 65#.

There is a rational explanation for what you experienced. IF the Felpro bolts you were sold were traditional head bolts and they broke before reaching 65#, there was either something wrong with the bolt or the wrench. If they were TTY bolts packaged with the wrong instructions, then that was the problem.

Good luck with the ARP bolts.

c

 

i'm interested in this also because i usually use felpro head bolts when i build an engine..

were you using the washers with the felpro bolts?

this is the part number i use for gen1 small blocks FEL-ES72856, should be the same for the lt1.

 

from what i've read felpro is now using torque to yield method.. i know within the last 2yrs i have used felpro head bolts on a gen1 sbc with cast iron heads and i just torqued them down to like 20ftlbs, 50ftlbs and then65ftlbs...

did find the info below on felpros site..

Fel-Pro offers a torque-to-angle indicator (part number TRQ-1) that takes the guesswork out of tightening head bolts. It’s an inexpensive gauge that fits on the 1/2” drive of a torque wrench and ensures torque-to-yield bolts are properly tightened.

Fel-Pro engineers recommend you never reuse a torque-to-yield head bolt. Chances are great that it has already exceeded its elasticity barrier and won’t spring back to properly seal the engine.

also this:
Fel-Pro ES72856 head bolt set 2 req'd. Future part number 21-1121. HP Books lists stock torque specs of 22ft/lbs first pass with final pass at 80degrees on medium and long bolts and 67degrees on short bolts.

 

felpro split the method of torque on the bolts i guess.. the way i read it anyways..

92-95 they use the 65ftlbs, in 3 steps..
96-97 they use the tty method, i think this is wierd but i believe this is the way gm also did it...
felpro uses the same part number for both though..

on the older gen1 stuff its all the 3 step torque method, 22ftlbs, 50ftlbs, 65ftlbs. using the same part number... i have used felpro head bolts on several engines i have built for myself and my father over the past few years, we have always used cast iron heads and i've alway torqued them to 65ftlbs, i go 20ftlbs, 50ftlbs, 65ftlbs and ive alwyas used a shot of oil on the washer and head of the bolt..

here felpros torque specifications guide.
http://olybrake.com/pdf/fel_pro_torque_specs_guide.pdf

 

350 (5.7L) Chevrolet Truck 2002-97 VIN R ●❍ 1st all bolts 22,
2nd Long bolts turn 75 degrees,
3rd Medium bolts turn 65 degrees,
4th Short bolts turn 55 degrees
7 ES 72856
350 (5.7L) Chevrolet Truck 1996 VIN R ●❍ 1st 24, 2nd 45, 3rd 65 7 ES 72856

350 (5.7L) Chevrolet 1997-96 VIN P, 5 ●❍ 1st all bolts 22,
2nd Short bolts turn 67 degrees,
3rd Medium bolts &
Long bolts turn 80 degrees
ES 72856

350 (5.7L) Chevrolet 1995-92 VIN P ●❍ 65 in three steps
ES 72856

350 (5.7L) Chevrolet 1995-67
Cast Iron heads
exc. VIN P, 5
●❍ 65 in three steps
ES 72856

350 (5.7L) Chevrolet 1991-86
Aluminum heads
exc. VIN P
●❍ Short Bolts 60; Medium Bolts 65;
Long Bolts 65
7 ES 72856

 

you also have to have use the correct side of the washer to the head of the bolt, there is a heavy chamfer that goes to the head of the bolt...

also,are you using newer model heads on an older block? maybe there is a difference in the spotface depths on the different heads.

 

Save yourself the hassle of using those bolts and just use ARP 134-3601. Torque them in 3 steps - 25#, 45#, 70#, done.

 

I used arp head stud kit for sbc and have never looked back. Once you go studs youll never buy another set of head bolts unless its in a spot where studs are not useable.

 

I think it was that part number, it was the same one that the federal mogul website had listed for my car, it didn't have any washers, both a local machine shop and o'reilly looked up the recommended torque spec for the fel pro bolts as a 3 step to 65#. My next step would have been to use the torque angle method, but if I do decide to keep the car after boot I'll wanna have reusable head bolts, so I decided to go with the ARP's. It seems as if everyone is finding the same info as I did, so I think I'll just chalk this one up to the car being cursed as well (for example, immediately after my first plug change the head gasket blew >.<)
All that I did notice is that the bolts thin out a little more than the stockers do. My next step is to see if FM will help me out with the 2 separate gaskets I used when their bolts broke Oh, sadly studs are a tad out of my price range or I would love them.

 

your original 93 model head bolts can be reused. just use them. they didnt change the bolts to tty till way later. theyre better than the tty crap youre gona get at autozone or where ever. warning: you must be sure that the motor has the original head bolts from factory. If you dont know if its a remanufactured motor or not then they may have used tty bolts. if thats the case get some from ARP.

 

Hopefully he figured this out in the almost 3 years since he asked the question.

 

Sorry, yeh I realized that after the fact. Lol! Maybe It'll be good help for someone searching down the road in the future.