15-02-2015, 02:50 PM
(This post was last modified: 15-02-2015, 02:51 PM by Chairchild.)
increasing the piston to head clearance does three things:
1) reduces static CR, so an immediate (if minimal) performance drop
2) reduces the amount of squish, which whilst not *as* important on an IDI diesel, it still reduces performance, ecomomy, and increases emissions
3) removes all chances of contact-cooling - where the piston gets so close to the head, it's considered as touching - whereby a minor amount of cooling occurs to the crown of the piston.
It won't induce knock - only the fuelling can do that. As you've got the head off, use a DTI gauge to measure piston protrusion from the block, and buy the best suited HG (covered by Haynes) for the highest piston
1) reduces static CR, so an immediate (if minimal) performance drop
2) reduces the amount of squish, which whilst not *as* important on an IDI diesel, it still reduces performance, ecomomy, and increases emissions
3) removes all chances of contact-cooling - where the piston gets so close to the head, it's considered as touching - whereby a minor amount of cooling occurs to the crown of the piston.
It won't induce knock - only the fuelling can do that. As you've got the head off, use a DTI gauge to measure piston protrusion from the block, and buy the best suited HG (covered by Haynes) for the highest piston