OK, toss out everything I know... Dulcich, chime in here...

[Deaf Bob]

Welcome to the site... Hopefully you will chime in often...

[TC]

I know of the benefits that going to a larger diameter lifter does for a flat tappet cam, but is there any benefit to running a larger diameter roller lifter on a roller cam??

[dave storlien]

larger dia lifyer is always a better deal

A larger dia lifter allows you to have a larger dia wheel and a larger a larger dia cam bore allows you to have a better lobe, all works hand in hand. Not big on roller cams though. I did a lot of work with the olds Quad 4 engine. It has a 1 3/8 dia lifter , no roller cam n the world will match the valve acceleration this thing has. We made 300 hp at 7000rpm with 138 cu in engine and 230deg at .050 on pump gas.

[BOOOGHAR]

ive always been fascinated by the quad 4 since they first came out, then got alot more interested in them when quad4rods started doing what they've done with them - BUT trying to find a quad4 now is like trying to find a needle in a haystack

[TC]

A larger dia lifter allows you to have a larger dia wheel and a larger a larger dia cam bore allows you to have a better lobe, all works hand in hand. Not big on roller cams though. I did a lot of work with the olds Quad 4 engine. It has a 1 3/8 dia lifter , no roller cam n the world will match the valve acceleration this thing has. We made 300 hp at 7000rpm with 138 cu in engine and 230deg at .050 on pump gas.

I got that out of Vizard's book on Valvetrains that there were limitations to a roller and that a flat tappet can achieve higher intensity rates....... Also at what point in designing the cam specs will you find yourself needing to go to a larger diameter lifter? You know at what lifts/durations, and do you know what the maximum amount of lifter intensity that can be achieved? or at that what would be the maximum amount you'd run on a lets say a drag week type car.....

[dave storlien]

How many do you need , I think I have parts for 4 engines. Now I,m working w the ecotec . The major problem is that the cam core is not big enough in Dia. to allow more than 230deg at .050.
As far as answering questions about EMC engines , you must remember that we had a max lift of .650 so the flat tappet I felt was a much better choice. The one thing I don,t see mentioned is that the lifter is spinning in the bore and hydro planing over the camshaft. Here is how you get a reduction in friction.

[dave storlien]

lifter and cam core dia

I,d say the confines of the block are the limiting factor

[Bob Holmes]

Great to see you here Dave. Thanks

[DanStokes]

Dave - Welcome to the madness! I'm a retired EPA dyno tech now doing Land Speed Racing in a VERY bottom-of-the-ladder sort of way. Great to have someone on here with your performance experience (no offense to a bunch of the other guys!).

Dan

[dave storlien]

Hello Dan
Thank you for your kind words. I have been looking at doing sum land speed racing also. I have an 86 Feiro I,m working on now . Putting a LNF ecotec in it. I feel like I,m cheating working with a turbo motor. But should be lots of fun when its done

Dave

[TC]

Oh ya, where are my manners, yes welcome to the forum Dave.

[Huskinhano]

Dave, that was a great article in ECM. I know that flat.tappet ks acceleration unlimited and thought your idea was slick. You remind me of Larry Widmer.

Looking forward to fufure posts and.comments.p

[Monk]

Running a solid roller myself......this is good stuff Dave.
Welcome.

[dave storlien]

Now that is a name I have not heard in years, Larry Widmer. Don,t know if I,m in that class. I,m just a cut and try kinda guy. But thank you