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Sun Mar 18, 2007 8:01 am

help on what size bolts going with 2110 i have seen rods for sale with 3/8 or 5/16 arp bolts witch would be best for the 82 mm crank is there a clearnce question here?

Sun Mar 18, 2007 8:09 am

VW or Buick(Chevy) journals?

Sun Mar 18, 2007 8:24 am

i will be using chevy rods

Sun Mar 18, 2007 8:34 am

You dont really hear the 5/16 letting go. The 3/8 would require more clearancing.

If you buy scat H beams the side clearances are usually tighter and for very high revving engines you might want to get them machined to increase side clearance to .016 - .018.

CB H beams are very strong with the arp2000 rod bolts and give alot of sideclearance for oil flow.

Get the 5.4 CB Hbeams and you'll be happy and it wont break the bank. Scats cost more but theres the option of going overkill with 3/8's. Nothing wrong with overkill.

I have both a set of 3/8 rod bolts scats and CB Hbeam 5/16 for both of my 2332 engines.

The Bugpack seems to be another chinese conrod blank but more $ usually but nice.

Sun Mar 18, 2007 8:41 am

I will go w/ the 3/8" bolts...any day. I have seen 5/16" failures in drag motors. Not pretty.

The clearance work is not that much more.

Sun Mar 18, 2007 8:50 am

nsracing wrote: I will go w/ the 3/8" bolts...any day. I have seen 5/16" failures in drag motors. Not pretty.

The clearance work is not that much more.

The 3/8's are of coarse better but in terms of failures I really dont hear of it that much. For drag cars I'd say its more suited to have 3/8's.

For a 2110 I am assuming its hotstreet and I've almost never heard of a 5/16 letting go.

Nsracing, clearance work cost $$$ thats probably an additional cost of 60+ dollars for "setup time" and shaving all 4 rods. I'm not so concerned of cost but its still more money ..bottom line. High revving will probably require this with a scat H beam but its not imperative. I am still using straight out of the box Scat H beams and I think my conrod bearings would look better with more side clearance. I may get them shaved when I take that motor apart.

For a 2110 with 7000rpms shift points a 5/16 rodbolt is gonna do a fine job.

I may just buy another set of scat H beams with 3/8's. I still haven't shi! kicked my CB's on my new motor.

Sun Mar 18, 2007 9:17 am

i had read that most of the h beam rods are imported from china not all!

Sun Mar 18, 2007 9:34 am

Vance72 wrote: i had read that most of the h beam rods are imported from china not all!

Most are china blanks. They are working fine.

If you want spend more money on some Pauter or carillo thats gonna be double to triple the cost of a CB Hbeam (china blank) In terms of reliability I'd say all will work well.

Sun Mar 18, 2007 10:20 am

i will go with the china rods 5/16 arp this just going to a street beetle

Sun Mar 18, 2007 10:24 am

I have never clearanced an H-Beam rod with 3/8" bolts...even with 88mm stroked full-flanged cranks. I like the rods intact for full strenght potential. Balancing the rods will require removal of material but they are close to each other from factory. There is minimal removal.

The only clearing is by the spigot areas where you notch the case. The 5/16 vs. 3/8 inch size headbolt size is almost nothing. The larger hex nuts from Chevy style rod bolts will require some clearing on the case spigots but not the 12-point ones.

I will use the 5/16 inch for street use, but I feel more comfortable with the 3/8 inch size.

Scat brands are good and have proven themselves to take some abuse.

The CBs are doing very good too from what I can see of the motors I built last year.

Bugpacks? I will ask someone else's experience on them. Has anyone used them in full race application?

Sun Mar 18, 2007 10:31 am

i wil be using a new high roof bug pack alum block and you like the 3/8 bolts better i just dont want cut the crap out of suff !

Sun Mar 18, 2007 11:01 am

You don't have to cut a lot to fit a 82mm Buick journal with H-beam rodfs and 3/8" bolts. I have a OEM case there's plenty of meat left.

Sun Mar 18, 2007 11:58 am

thanks for the info i will go with 3/8 bolts

Wed May 11, 2011 2:36 pm

I know this is an old thread, but I didn't want to create another.

What is the difference between 5/16 and 3/8 connecting rod bolts? (besides 1/16")

Is this refering to the bolts that hold the connecting rod together, or how it attaches to the piston?

Wed May 11, 2011 3:26 pm

Those are the bolts that hold the rod together on the crank throw. The rod attaches to the piston via a wrist pin (or gudgeon pin if you are Olde English).

Wed May 11, 2011 7:00 pm

cool, thanks

Wed Jul 27, 2011 5:38 am

It's interesting that either size bolt has a Yield tensil strength of 200,000PSI.

Wed Jul 27, 2011 8:46 am

Whats the chance when you buy a set of chinese rods that the bolts are counterfeit? I bought a set of CB HD uni-tech rods with ARP bolts, I think I trust CB, but what about other companies?

Casey

Wed Jul 27, 2011 8:50 am

Ford ran 5/16" rod bolts in almost all there small blocks except the HiPo 289 and the Boss 302, I have pushed a 289 with 5/16" bolts to 6700 rpm with no problem, and this was on a 30 year old motor.

Casey

Wed Jul 27, 2011 9:03 am

I've run to 8k with 5/16", no need for bigger IMO.