Some disgusting pics
Jul 16, 2015 | 10:51 AM
#12
Formerly ScreamingL
Joined: Oct 2003
Posts: 3,456
Likes: 5
From: From the 412
Leakdown results on cold motor. After messing around with the gauge and slight variations in piston position on 1 cylindeer, I would say some of these numbers could be a few % high. Total seal 1.5mm stainless top ring gapped at .024 and 1.5mm Napier 2nd gapped at .024. 3mm oil.
GM service manual for a stock engine says leakage should be under 25%.
Some of the cylinders with the best numbers actually have the most crud on them.
1- 20
2- 20
3- 12
4- 12
5- 18
6- 18
7- 15
8- 20
1-20____2-20
3-12____4-12
5-18____6-18
7-15____8-20
GM service manual for a stock engine says leakage should be under 25%.
Some of the cylinders with the best numbers actually have the most crud on them.
1- 20
2- 20
3- 12
4- 12
5- 18
6- 18
7- 15
8- 20
1-20____2-20
3-12____4-12
5-18____6-18
7-15____8-20
Jul 16, 2015 | 10:58 AM
#13
Guess it didn't help that the valve seals were getting hammered on the first go round. They look OK this time. But then again, the intake ports looked cleaner back then??? Petty brown/black now.
Last edited by DrX; Jul 16, 2015 at 12:54 PM.
Jul 20, 2015 | 01:45 PM
#18
i see your ported heads have the rocker arm bolt holes open. they usually are like that with ported heads. did u use lock tight or thread sealer on those by chance? bc they will leak oil into intake runners without it.
Jul 20, 2015 | 02:43 PM
#19
I was thinking the same thing. Heads were assembled by the engine builder. I know I had a sealer for bolts like that when I rebuilt one of my outboard motors.
