Rod bolts - torque or stretch

A

Anonymous

Guest
How many of you tighten connecting rod bolts with a stretch gauge v.s. how many by torque wrench?

:D
 

Phantom

Pro Stocker
Oct 9, 2004
1,709
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DeSoto Wi
I use a Stretch gauge now but assembled over 35 engines by just torqueing the bolts before and never had a rod bolt fail.
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,847
1
38
North Jersey
When I built my own stuff I torqued because I don't have a stretch gauge. IIRC, my engine builder uses a stretch gauge. There's nothing wrong with going by torque, stretch is just a more accurate method.

Tommy
 

Goob

Top Fueler
Jun 6, 2003
3,641
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Indianapolis
Stretching them here for several years now........never had a problem with the torque method either, but now that I see the difference between the torque wrench and the stretch, I'll never go by torque alone again.

If you're going to be serious about your engine maintenance, it's critical to measure the bolts at disassembly, any bolts that don't get back to their original length are junk.
 

K-Star automotive

Amateur Racer
Feb 6, 2006
207
0
0
York, Pa
www.kstarautomotive.com
bolts

Stretch only... I spent a bunch of hours doing R & D on this subject and stretching it the only correct way....

Don't confuse what people "get away with" and the correct way to do a job...

I to have built 25/30 engines before i started using the stretch method and "got away" with it.....but others are not as lucky .The problem is that they have problems but something else gets the blame for the failure....

This is all in respect to aftermarket bolts.....

Check the new bolts for length..... I have found that you need to cycle the bolts once, then record the relaxed length... keep it for when you freshen up the engine.... Any bolt that grows .0010" or more needs junked. I have found that the new bolts grow a bit, maybe .0005" or so during the first cycle, then take a set to that length....


Keith
 
A

Anonymous

Guest
Thread starter
Re: bolts

K-Star automotive said:
Stretch only... I spent a bunch of hours doing R & D on this subject and stretching it the only correct way....

Don't confuse what people "get away with" and the correct way to do a job...

I to have built 25/30 engines before i started using the stretch method and "got away" with it.....but others are not as lucky .The problem is that they have problems but something else gets the blame for the failure....

This is all in respect to aftermarket bolts.....

Check the new bolts for length..... I have found that you need to cycle the bolts once, then record the relaxed length... keep it for when you freshen up the engine.... Any bolt that grows .0010" or more needs junked. I have found that the new bolts grow a bit, maybe .0005" or so during the first cycle, then take a set to that length....


Keith

if you go with the stretch method, whats the use for having a torque spec??.. i too have assembled many motors with only the torque specs and no failure's........BUT whats to gain from stretch and torque on a high dollar set of rod bolt upgrade??.. i know it's more accurate but most manufactures don't list a stretch but just the torque..?? isn't the bolt stretch the same as what the torque spec is??
 
A

Anonymous

Guest
Thread starter
BOTH

as i dont have a strech gauge, my machienst streches the bolt to the desired strech and records the torqued need to get there with regular oil. this as worked for him for some 25Plus years of building street motors to 5 second top alchole funny car motors
 

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