: GMPT PV8 (Northstar) engine Cylinder Liner help...



EngnFrnzy
08-24-04, 03:39 PM
I have heard that a company called "Moosley" makes the cylinder liners for the 2003 PV8 Northstar. Are they cast-in-place iron cylinder liners. Can the block be bored? Where can I find "Moosley" liners?

foo
08-24-04, 04:25 PM
well on the older northstars the liners are 'permanently' stuck in the cylinders.. there isn't any way to remove them (at least easily). GM suggests replacing the block if the liners get damaged or something else on the block that can't be repaired easily. I've wanted to rebuild my engine just because it's burning a ton of oil (they all do this I guess) and while i'm in there increase the bore a little but from reading up i don't think it's possible

Anthony Cipriano
08-25-04, 03:59 PM
All Northstar engines have cast in place iron cylinder liners. The cylinder liner cannot be removed by pressing or any way other than simply boring it completely away and then pressing a new (aftermarket) cylinder liner in place. Given the die cast block and strength of the aluminum surround around the iron liner I would not expect great success with this approach. Theoretically it is feasible but practically it may prove unworkable. I've never attempted it.

There's sufficient stock on the OEM cylinder liners to overbore by 1 mm on the diameter. Not enough for a significant displacement increase but enough to re-man the engine if necessary.

If you are considering a teardown and rebuild you should inspect the cylinders and pistons before planning an overbore. Chances are the original cylinders are perfect and still have the original OEM honing pattern in them. My observations on some very high mileage Norhtstar engines is that they have little to no bore wear after hundreds of thousands of miles. One of the side benefits of the extra oil consumption.

Oil is much cheaper than a rebuild anyway so why bother if oil consumption is the question. Just keep putting oil in it. You can buy lots of oil for the cost of a teardown and inspection and rebuild.