darrrrrn....I have a sstripped cam cap bolt hole!!!!!!!!

Check out this guy's work... It's called 'doweling and strapping.' He actually oversized *all* of the main cap studs and put a good chunk of steel over each one. He claims 1000hp out of a 4.3L Chevy.

Even 8ft/lb is way too much. For some reason it will always be the exhaust caps that strip. Don't know if there's less thread there or softer aluminum from the heat or what the exact reason is. I go 5.5 ft/lb with caution even at that torque. If it feels funny, stop before stripping. The helicoils do the trick for the repair just fine. I was just reading a Clymer here and it's chock full of great advice. "Never reuse a shim as they are worn. Always discard and use a new shim for valve clearance adjustment". That's great advice there along with the 12 ft/lb on the caps. :pinch:

I totally dissagree with that,Ron.
8 FT/pounds is NOT too much for the cam caps.
As long as the threads HAVEN'T been weakened or
stretched from over-torqueing,8 FT/pounds is OK.

Another thing...using FT/pounds would usually mean that you're
using a HUGE torque wrench,when you SHOULD be using a small,
INCH/pound wrench(way less leverage),to get a better "Feeling"
of when that bolt IS tight enough.
You WON'T get that feeling,using a FT/pound wrench on such a
small bolt...period.

I'm just used to using the old ft/lb term, since in/lb really wasn't ever used back in the old days. I've got both in/lb and ft/lb torque ratchets though and both give that same insecure feeling on the exhaust caps. Intakes no problem at 8 ft/lb, but exhausts are real iffy. I'm sure it makes a difference how many times the caps have been off too. I know I've stripped them myself at 8 so I'd be careful is all I'd recommend.

Sandy wrote:

I totally dissagree with that,Ron.
8 FT/pounds is NOT too much for the cam caps.
As long as the threads HAVEN'T been weakened or
stretched from over-torqueing,8 FT/pounds is OK.

That's what I use, about 100 inch-pounds. You need a low-range torque wrench to keep from accidentally over torquing.

BTW, the FSM spec for mine is 95 - 110 inch pounds which is about 8 - 9.1 ft-lbs. 100 inch pounds is about on nominal.

Sandy wrote:

I totally dissagree with that,Ron.
8 FT/pounds is NOT too much for the cam caps.
As long as the threads HAVEN'T been weakened or
stretched from over-torqueing,8 FT/pounds is OK.

Another thing...using FT/pounds would usually mean that you're using a HUGE torque wrench,when you SHOULD be using a small,INCH/pound wrench(way less leverage),to get a better "Feeling" of when that bolt IS tight enough.
You WON'T get that feeling,using a FT/pound wrench on such a
small bolt...period.

Bullseye.

RonKZ650 wrote:

I'm just used to using the old ft/lb term, since in/lb really wasn't ever used back in the old days. I've got both in/lb and ft/lb torque ratchets though and both give that same insecure feeling on the exhaust caps. Intakes no problem at 8 ft/lb, but exhausts are real iffy. I'm sure it makes a difference how many times the caps have been off too. I know I've stripped them myself at 8 so I'd be careful is all I'd recommend.

True, the damage is usually done by the last idiot who worked on it and you are the person who applies the right torque and shears off the weakened threads.

I used an INCH-POUND click-type torque wrench when I did my camshafts. I agree about the 'feel' of the wrench when physically smaller than the standard size deflecting beam wrench. I was extremely careful but I torqued the bolts to 100LB/IN (8.5 LB/FT) which is what my manual specified.
As far as trying to drill/tap/helicoil this hole I would think it would be better to simply pull the camshaft in question and do the work rather than trying to keep in installed and risk getting any metal shavings under the cam.
Just my 1% for the day.

Beatpoet wrote:

Check out this guy's work... It's called 'doweling and strapping.' He actually oversized *all* of the main cap studs and put a good chunk of steel over each one. He claims 1000hp out of a 4.3L Chevy.

if you look in the area where a set of 4bolt main caps would run the outer bolts there is no meat there,the steel strap is much stronger than the stock cast iron cap and the studs are just cheap insurance.

My 79 1000ST had the same problem (stripped cam bolt threads) and the bolts were NOT over-tightened. The aluminum was weakened by heat. I read somewhere (maybe on this forum in a previous thread) that the 79 and 80 MKII engines were more susceptible to this problem. Maybe from a different alloy or casting process?...Anyway, I re-tapped all my cam bolt holes to 1/4-20. The 1/4 inch bolt is slightly larger than 6mm but will still pass through the steel alignment dowel. So far so good.

bountyhunter wrote:

RonKZ650 wrote:

I'm just used to using the old ft/lb term, since in/lb really wasn't ever used back in the old days. I've got both in/lb and ft/lb torque ratchets though and both give that same insecure feeling on the exhaust caps. Intakes no problem at 8 ft/lb, but exhausts are real iffy. I'm sure it makes a difference how many times the caps have been off too. I know I've stripped them myself at 8 so I'd be careful is all I'd recommend.

True, the damage is usually done by the last idiot who worked on it and you are the person who applies the right torque and shears off the weakened threads.

So very sad,and so very true!
I hear what you're saying,Ron.
I never thought about the heat-factor,and the "exhaust" cam-caps
being the weaker link.
Gotta wonder now,of all the people that HAVE had the unfortunate
experience of stripping those bolts...
were they intake,or exhaust?:huh:

think about which rocker arm normally fails 1st on a car motor,its the exhuast side from all the heat on exhuast valve:(