H-I-J '76 Nova re-fit.

[Nmbr1GMfan]

Originally Posted by Jim Hanig

Just a though ,make sure the screw in plugs in the front are not in to deep, Center one .

Yes, they were checked carefully.

[Nmbr1GMfan]

It was nice to get away from the engine for a day (we'll be back to that tomorrow) Autumn and I went down to work on the car today. Although I may get hamered here for this kind of work, we had a nice afternoon cleaning the underneath/underhood of the car.

[Dissident]

Todd,
Someone mentioned that the thing would live.....but recent history doesn't support that notion. If you were running on the dyno at 600rpm/sec and going from 4000 to 7500, that only takes 5.833 seconds at 300rpm/sec twice that time. SO, if you total the pulls in time, that is not a livable package.Normal lifter to bore clearances is where a normal leak occurs. If it is sloppy, as an example 0.002", that leakage is approx equal to a jet of about 0.058" diameter oer lifter bore/lifter and that is additional to the groove that somebody increased the leakage path with. That flow number would scare most folks.Not a good package at all. IF you had the block reamed and honed for larger lifters, it would probably take a 0.904" lifter to clean up the groove leak. Yeah, not legal, but might save the block but would cost for another set of lifters and the cost of increasing the lifter bores. BTW - all that leakage and resultant deluge drops right down on the rotating assembly and the windage losses go up exponentially with RPM.


The lifter/bore flow above is in excess of 8gpm!!!


Best of luck to you and Autumn. Hope you get to race soon.

Regards,
HB2
Dissident

[Nmbr1GMfan]

Originally Posted by Dissident

Todd,
Someone mentioned that the thing would live.....but recent history doesn't support that notion. If you were running on the dyno at 600rpm/sec and going from 4000 to 7500, that only takes 5.833 seconds at 300rpm/sec twice that time. SO, if you total the pulls in time, that is not a livable package.Normal lifter to bore clearances is where a normal leak occurs. If it is sloppy, as an example 0.002", that leakage is approx equal to a jet of about 0.058" diameter oer lifter bore/lifter and that is additional to the groove that somebody increased the leakage path with. That flow number would scare most folks.Not a good package at all. IF you had the block reamed and honed for larger lifters, it would probably take a 0.904" lifter to clean up the groove leak. Yeah, not legal, but might save the block but would cost for another set of lifters and the cost of increasing the lifter bores. BTW - all that leakage and resultant deluge drops right down on the rotating assembly and the windage losses go up exponentially with RPM.



Best of luck to you and Autumn. Hope you get to race soon.


Regards,
HB2
Dissident

In my mind, the only difference between then and now, is lifters. These lifters have two real differences from the old lifters, the oil flowing from the edm hole and the extra oil pumped to the top (which I believe is more than the edm hole flow). So if I restrict the oil so less goes to the top and I plug the edm holes (or get non edm lifters) that should get me back to square one. I could even add a hv pump for insurance. Thanks for the replies.

[HP HUNTER]

Do you have Trend lifters in this engine?

[killintime6968]

If you can get or borrow a set of clear plexiglass rocker covers to use when on the dyno it might also give you a visual perspective on whats going on.

[Nmbr1GMfan]

Originally Posted by HP HUNTER

Do you have Trend lifters in this engine?

They're Bullets edm lifters. I don't know who manufactures them for Bullet.

[Kenny McCoy]

Originally Posted by Nmbr1GMfan

In my mind, the only difference between then and now, is lifters. These lifters have two real differences from the old lifters, the oil flowing from the edm hole and the extra oil pumped to the top (which I believe is more than the edm hole flow). So if I restrict the oil so less goes to the top and I plug the edm holes (or get non edm lifters) that should get me back to square one. I could even add a hv pump for insurance. Thanks for the replies.

Need way less oil up top then you think you do..

[Dwight Southerland]

Originally Posted by Kenny McCoy

Need way less oil up top then you think you do..

Especially with roller rocker arms.

[Glenn Briglio]

Might want to start with oil restrictors with .060 hole in them on engine stand and prime engine to see results up top.You can always make the hole bigger.