I took a head off my 327 today to see how much of a ring ridge I had. Turns out there is just a hint of it, in some spots I can't feel any. The engine had less than 50 thousand miles on it. So I'm not going with an overbore.
My cheap 327 budget plan was to cut the ridge, and just simply replace the piston with new 4" stock bore replacements, giving the bores a 45 ° glaze break with a Flex hone. Then install self gapped file fit rings. I've yet to flip it over and check the journal condition. If good it'll just get new bearings. New pistons are really cheap, like $150 Cdn.
Question about rings;
Is the current best practice to go with Plasma Moly coated ductile iron rings? Looking on line it seems they are the most commonly used ring today.
What grit hone should I use in the bores if running Moly rings?
Thanks, Mark
__________________
65 Laurentian post, 67 Grande Parisienne 4 door HT.
It might re-ring fine. Best bet is to strip it, get it cleaned and get the bores measured. The engine shop will advise on the best rings. Do the cam bearings and Welch plugs while it is apart.
In my experience bearings wear out faster than rings, as you are pulling it apart use some plastiguage and see what clearance is there. You can buy .001 bearings as well as standard.
Now this is good thinking, I had never thought to do this.
Mark, did you see this---
"You can measure the bore wear just below the ridge without using any high tech expensive equipment. Put a ring in the bore - square it up with a piston from the top.
measure the ring gap. Push the ring to the bottom of the bore, measure the ring gap. Divide the difference in the gaps by 3 (well 3.142 if you wish to be pedantic) and this is the wear on the bore diameter
And yes as stated the ridge is the unworn original diameter of the bore."
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
Funny...just doing the same thing! Just on a 283..not the big 327. have you looked at Rock auto rebuild kits? Never heard of enginetech...but I'm sure they don't make their own parts,so could be getting the same parts as other kits? Just doing a stocker rebuild on mine and yes..may not need re bored..just see what the max allowance is on a stock bore and go from there. Have done this before...use the piston(inverted) to push the ring down...this will keep it true to the cyl wall. My project that has been sitting for 40 years(heads/intake off) at dads. Can also get sealedpower kit.
They seem to have the best prices and always are good on the phone with me when I call. I didn't used to like Hastings rings way back when because my brother had major oil burning issues with them at his repair shop but I know guys now who use them and say they are fine. I used to always buy Sealed Power rings.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
The Rock Auto kit for my engine IS cheaper than Northern Auto but I'm the kind of guy who's old and crusty, set in my ways! I am betting the Enginetech kits are fine, or they wouldn't be selling them.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
The Rock Auto kit for my engine IS cheaper than Northern Auto but I'm the kind of guy who's old and crusty, set in my ways! I am betting the Enginetech kits are fine, or they wouldn't be selling them.
Notice I got my lifters out.....a week of soaking and tapping! Bores r good.
Good stuff. That can be pretty stressful sometimes. It's a bit scary when you have to use some grunt to get them out. You worry how that bore is going to look.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
There's an Engine Tech here in Edmonton. It's an actual rebuild shop. We at work had experience with them and personally I wouldn't let them rebuild my wheelbarrow. But parts are parts. I'm talking about workmanship. My two bits.
__________________
'68 Parisienne 2+2 Convertible Matador Red (Resale Red but not for sale).
I hear you John, most of the places down here I wouldn't trust much with my stuff. Sometimes there is no choice. This time it appears I might have a choice. I might let them clean the block though..maybe.
Jim, I was blessed with lifters that just came right out with no effort, to which I'm thankful. If they were stuck, I would have pulled them up as far as they would go, then pulled the cam and maybe dropped them out the bottom?
Anyway, took some caps off and pulled 1-2 piston. Journals look to be in good condition, and I cannot feel ANY ring ridge, at least in these two bores. So maybe this 327 is candidate for a simple refresh?
__________________
65 Laurentian post, 67 Grande Parisienne 4 door HT.
I am surprised by the hone marks also. The piston rings used back then where hard as nails with lots of tension and wore the cylinder as much as the rings. Has the engine been rebuilt? I would clean off the tops of the pistons and check for being stamped oversize. I also agree with Carl, I reringed lots of engines back in the 70s with no problems. Some had such a high ridge that I had to ridge ream to get the pistons out. Back in the 70s, 80,000 miles was high mileage on a car. Most people traded every three to five years.
I'm even thinking about re-using the pistons and only doing new rings.. They are dirty, but could be cleaned up pretty easily. The skirts aren't even scuffed. Mind you, I only have two out so far.
__________________
65 Laurentian post, 67 Grande Parisienne 4 door HT.
I'm with Prefectca, the original top ring and oil rings on these were chrome plated rings and were hard on bores. It may just be a fairly low mile engine though.
If the bore comes up within tolerance, hone it, re-use the pistons and re-ring it. You can buy a tool to de-carbonise the ring slots. Before you pull all pistons out use some plastigauge on a few journals.
have you looked at Rock auto rebuild kits? Never heard of enginetech...but I'm sure they don't make their own parts,so could be getting the same parts as other kits? Just doing a stocker rebuild on mine and yes..may not need re bored..just see what the max allowance is on a stock bore and go from there. Have done this before...use the piston(inverted) to push the ring down...this will keep it true to the cyl wall. My project that has been sitting for 40 years(heads/intake off) at dads. Can also get sealedpower kit.
