[68WarDog]

I will be detuning this former 12:1 455+.060) , stock stroke race engine. Replacing the 72cc Eheads round port with the 85cc version. The cam will remain, it's an UD solid roller, 243/251@.050, .640 lift with 1.6 scorpion. Moroso 7qt pan, windage tray and scraper. This engine propel a second generation F body 6.8/6.9 , 97/98 mph 1/8 mile with. T400, 3.50 gear, 32-3400 tci stall. Will exchange the solid roller lifters with a quality hydraulic roller lifter. I'm not a fan of the CC 857. Had a couple of bad experiences when they first hit the market. What is a quality Pontiac hydraulic roller lifter? And with this hybrid setup what's a good tight lash starting point?

[tom s]

Try the newest Comps,just got a set,they have a replaceable cartridge.Butler had them Evolution's.Tom

[68WarDog]

Originally Posted by tom s

Try the newest Comps,just got a set,they have a replaceable cartridge.Butler had them Evolution's.Tom

Tom, have you had the opportunity to installed them? Are they as quiet as advertised?

[AG]

I recently installed a set in a 1971 455HO and was very impressed with the quality. They were very quiet right away on the initial start-up, I would use them again.

[Stan Weiss]

Originally Posted by 68WarDog

I will be detuning this former 12:1 455+.060) , stock stroke race engine. Replacing the 72cc Eheads round port with the 85cc version. The cam will remain, it's an UD solid roller, 243/251@.050, .640 lift with 1.6 scorpion. Moroso 7qt pan, windage tray and scraper. This engine propel a second generation F body 6.8/6.9 , 97/98 mph 1/8 mile with. T400, 3.50 gear, 32-3400 tci stall. Will exchange the solid roller lifters with a quality hydraulic roller lifter. I'm not a fan of the CC 857. Had a couple of bad experiences when they first hit the market. What is a quality Pontiac hydraulic roller lifter? And with this hybrid setup what's a good tight lash starting point?

What do you think is going to happen to your idle quality when you put hydraulic lifters on a solid lifter cam?

Stan

[Half-Inch Stud]

That cam and 87 cc heads ought to hold idle...... better than my cam at 9.00:1 which held idle.

[68WarDog]

Originally Posted by Stan Weiss

What do you think is going to happen to your idle quality when you put hydraulic lifters on a solid lifter cam?

Stan

Idle quality should not be an issue. I have a custom Holley 850 dp built by Jeff >12 years ago, and 1k rpm Idle is SOP for me using street solid roller. And according to Wallaceracing.com site, I'll be reducing cr from 13.2 to 11.4.. Don't know exactly how that will affect power loss.

[Stan Weiss]

Originally Posted by 68WarDog

Idle quality should not be an issue. I have a custom Holley 850 dp built by Jeff >12 years ago, and 1k rpm Idle is SOP for me using street solid roller. And according to Wallaceracing.com site, I'll be reducing cr from 13.2 to 11.4.. Don't know exactly how that will affect power loss.

What are you setting your lash at now? Unless you are using a very tight lash setting, going from solid lifters to hydraulic lifters will make the cam look bigger to your engine.

I don't have a Cam Dr file for your cam. This shows a lobe I modified for something else. It is 243.x @ 0.050" and about 0.39" lobe lift. You can see the large increase in seat_to_seat duration which also will increase overlap with reducing the lash setting.

Stan

[rohrt]

I was in the same boat for the same reason. CC early 857 were junk. Made all kinds of noise regardless of the pre load set.

I researched my option to death and decided on going with the JohnsonLifters ST21120PR Sht Trav Preload .030. Of all the lifters discussed in these forums they were the ones with almost no complaints.

They were quiet as soon as I started the car and have been since. Granted I just got it road worthy and I have not put many miles on it.
On the plus side, I expected to have to change out the pushrods but they ended up being spot on for me.

[steve25]

Looks like you will drop off about 2.5% of the power that you had with the higher compression.

Also note that all things being equal bigger combustion chambers will make for less idle vacuum.

[i82much]

what about advancing your cam a smidge?

[68WarDog]

Originally Posted by AG

I recently installed a set in a 1971 455HO and was very impressed with the quality. They were very quiet right away on the initial start-up, I would use them again.

AG, I'm assuming you're referring to the "evolution: brand?(

[68WarDog]

Originally Posted by Stan Weiss

What are you setting your lash at now? Unless you are using a very tight lash setting, going from solid lifters to hydraulic lifters will make the cam look bigger to your engine.

I don't have a Cam Dr file for your cam. This shows a lobe I modified for something else. It is 243.x @ 0.050" and about 0.39" lobe lift. You can see the large increase in seat_to_seat duration which also will increase overlap with reducing the lash setting.

Stan

Stan , hot lash will.be .022. I don't have the cam card with me. I recall talking with Harold back in the early 90s and something he mentioned always stayed with me, although 🚻 aggressive lobes, his lobes were alot gentler on valve spring components than Comp or Crane .

[68WarDog]

Originally Posted by i82much

what about advancing your cam a smidge?

Something I have considered, but cautionary, since I'm at 11.5 cr with 104 icl..

[AG]

Originally Posted by 68WarDog

AG, I'm assuming you're referring to the "evolution: brand?(

Yes I am.