Con rods

Hi 87 velo,

I believe the HQ Racers have to use the standard red motor rods (not the blue motor ones). I believe the red motor rods use the 5/16" rod bolts. The blue motor rods use the slightly larger 11/32" rod bolts (the blue motor rods use the same size as a small journal small block Chev rod bolt). ARP sell rod bolts for both red and blue motor rods. I understand that one of the mods the HQ racers do to their engines is to use the 5/16" ARP rod bolts.

Just be aware that the ARP bolts are a higher tensile bolt, so when you torque them up, they may need slightly more torque than a standard bolt. I was told once by an engine reconditioner that if you don't torque the ARP bolts up enough to get the correct amount of rod bolt stretch, they may come undone. If you do them up to their higher torque setting however, this may alter the 'out-of-round' at the big end. So he said that if you fit ARP rod bolts you should have them closed and honed after fitting the new rod bolts, to suit the new torque setting.

I have seen the red motor rod bolts for sale on eBay a few months ago - they were no cheaper than the blue motor bolts. I think they were around $140 per set.

Tortoise.