RV8 Cross bolting

[sparkythecat]

Hear mention on here from time to time of RV8 engine blocks being cross bolted.
Call me Mr Thicky if you like, but please can someone explain to me what exactly is bolted to what, and what advantage this cross bolted engine has over an unbolted one.

[GreenV8S]

The main bearing caps are secured sideways by bolts through the side of the block, in additional to the normal bolts upwards. It is supposed to stiffen the whole thing and stop it all flexing.

[Boosted LS1]

GreenV8S said:

The main bearing caps are secured sideways by bolts through the side of the block, in additional to the normal bolts upwards. It is supposed to stiffen the whole thing and stop it all flexing.

It certainly does brace the lower end. I once built a cross-bolted engine, fitted the crank and torqued the caps and turned the crank. It felt a bit tight. Once I fitted the cross bolts it spun much more freely


Boosted.

[chuntington101]

can this be done to ANY road engine? seams a easyway to make the mains much stronger.

Chris.

[Boosted LS1]

chuntington101 said:

can this be done to ANY road engine? seams a easyway to make the mains much stronger. Chris.

No, not if the blocks aren't fairly knew. It's a costly conversion even on newer non-crossbolted blocks. A duralloy ladder girdle and cap spacers, fitted across the sump/block face is much cheaper to do.

For non rovers it will depend on where the caps sit relative to the sump line and how mych material is on the caps. I'm doing a girdle for a 24v cosworth and that's proved to need a lot of thought, unlike the rover which is a very simple conversion.

Boosted.

>> Edited by Boosted LS1 on Thursday 16th December 17:58