LSX user

A lot of builders are spending $300+ on studs for heads and/or mains. I'm curious why. I understand if you tear down your engine every week but if this is a one and done build, why choose studs over bolts on your LS build? I spent months in school learning about threads and all the math that makes it all work. The diameter, number of threads, pitch, length, type of metal, heat treat of the metal etc. It all has a purpose and reason. We all know what GM uses, I'm just curious why some builders choose expensive studs. If there is a technical reason I'd like to hear it. Thanks everyone.

98CayenneT/A

Studs are a lot easier on the block threads.

Also a big reason for me using studs is you don't have to worry about pushing something through a water jacket and cracking your block.

pantera_efi

iTrader: (1)

Hi LSX, I will add to the above quality tech, the block material & model ?

I like head studs that "match" the OEM Bolt Stretch Rate, mine do.

I STATE that the cost of Main Studs/Aline Hole is equal when the main caps are replace with steel caps OR left as the OEM Powder Metal Cap.

The last person I told this to FOUND a set of LS-7 Caps for a cost of $150.00.

Lance

Che70velle

iTrader: (6)

Lance I agree. IF you are referencing fitting ls7 caps to an ls block, it won’t work. The bolt register spacing is different on the ls7/ls9 caps vs. other ls blocks. I bought a nice set of ls7/ls9 caps, and found out the hard way.
I ended up going Katech pinned main caps on my ls2 block.

LSX user

Some people use studs as a preference. That's fine. It's a big expense so I was just curious. I retired from Chevrolet. I worked at Powertrain in the tooling dept. My money says, crank on that bolt and eventually the head will come off. The block threads will still be in the block. The pressure threads exert on the bolts head is tremendous. It's the intended design. Car wheels=studs, Balancer=bolt.
A quick story. One afternoon at a GM stamping plant a cylinder head on a counterbalance cylinder for a 2000 ton press blasted off. It went through the roof and was never found. We think it landed in a farm field. That head was 4' in diameter and was 4" thick and weighed tons. It was held in place by 2 dozen 2" diameter studs/nuts. We think some oil got into the cylinder and it exploded. Either it ignited or there was enough oil trapped inside that well.....you can't compress a liquid so, something had to give. In either case the pressure was enormous.
On my new LS3 build I'm using ARP bolts on the heads. Great quality control, heat treat is spot on and the threads are rolled not cut. I'm old school and TTY would save me maybe $50. If I could find the right thread/length in a cap screw I'd use that and save a $100.
The factory bolts story is long and technical and ends up in the accounting dept.

CAMSTER

iTrader: (10)

I have used mostly studs for mains and heads but tired of fixing header flange damage head stud threads my latest build got head bolts.

Just to make sure equal care is taken for both bolts and studs as either will crack the block if oil or coolant gets trapped specially when using fastener assembly lubricant.