Don Terrill’s Speed-Talk

Monza355 wrote: ↑Thu Jan 09, 2020 4:29 pm

Walter R. Malik wrote: ↑Mon Jan 06, 2020 8:23 pm

Monza355 wrote: ↑Mon Jan 06, 2020 3:49 pm

I understand. I mentioned the redline because i want to go to the drag strip on occasion, but since this is primarily a street car good manners, reliability and the fact itmust be able to run on 91 octane pump gas are very important factors of this build. Much more important than maximum horsepower.

Personally ... I would simply get a Lunati "Voo-Doo" hydraulic flat tappet, 227/233 grind with the Victor Jr. intake.
#10120703 ... 268/276 off the seat, .489"/.504" valve lift, 110 separation; 106 intake C/L.
A 1.6/1 intake rocker for a little more lift.

EDIT: There must be plenty of others within the same realm.

I did think about going with a simple flat tappet camshaft. But i’ Not sure that it fits because of the long stroke because of the base circle.

You can get a flat tappet on a .900 BC

Yes i know they make a sb flat tappet camshafts, but i don't think that an iron noodle camshaft is such a great idea for longevity but i might be wrong there.

Monza355 wrote: ↑Thu Jan 09, 2020 4:40 pm Yes i know they make a sb flat tappet camshafts, but i don't think that an iron noodle camshaft is such a great idea for longevity but i might be wrong there.

Ive used them with no issues, but I no longer use flat tappet cams period. They just aren't worth the potential damage to all the hard work that goes into a good short block to me.

double post

Monza355 wrote: ↑Thu Jan 09, 2020 4:29 pm

Walter R. Malik wrote: ↑Mon Jan 06, 2020 8:23 pm
Personally ... I would simply get a Lunati "Voo-Doo" hydraulic flat tappet, 227/233 grind with the Victor Jr. intake.
#10120703 ... 268/276 off the seat, .489"/.504" valve lift, 110 separation; 106 intake C/L.
A 1.6/1 intake rocker for a little more lift.

EDIT: There must be plenty of others within the same realm.

I did think about going with a simple flat tappet camshaft. But i’ Not sure that it fits because of the long stroke because of the base circle.

A flat tappet camshaft lobe is considerably narrower on the flank than a normal small base circle roller lobe.
However, if the rods are not "stroker" rods then there may be an issue with either.

Monza355 wrote: ↑Thu Jan 09, 2020 4:40 pm Yes i know they make a sb flat tappet camshafts, but i don't think that an iron noodle camshaft is such a great idea for longevity but i might be wrong there.

The last thing you want to do with a flat tappet is reduce the base circle. You will end up with smaller nose radius and that's bad for longevity.

Put a solid roller in it.

Charliesauto wrote: ↑Thu Jan 09, 2020 6:19 pm

Monza355 wrote: ↑Thu Jan 09, 2020 4:40 pm Yes i know they make a sb flat tappet camshafts, but i don't think that an iron noodle camshaft is such a great idea for longevity but i might be wrong there.

The last thing you want to do with a flat tappet is reduce the base circle. You will end up with smaller nose radius and that's bad for longevity.

Put a solid roller in it.

Yes. I will use the solid roller. What stall have you guys used in an application like this. Would i be able to go with little higher stall and still drive decent on the street ?

Walter R. Malik wrote: ↑Thu Jan 09, 2020 5:36 pm

Monza355 wrote: ↑Thu Jan 09, 2020 4:29 pm

Walter R. Malik wrote: ↑Mon Jan 06, 2020 8:23 pm
Personally ... I would simply get a Lunati "Voo-Doo" hydraulic flat tappet, 227/233 grind with the Victor Jr. intake.
#10120703 ... 268/276 off the seat, .489"/.504" valve lift, 110 separation; 106 intake C/L.
A 1.6/1 intake rocker for a little more lift.

EDIT: There must be plenty of others within the same realm.

I did think about going with a simple flat tappet camshaft. But i’ Not sure that it fits because of the long stroke because of the base circle.

A flat tappet camshaft lobe is considerably narrower on the flank than a normal small base circle roller lobe.
However, if the rods are not "stroker" rods then there may be an issue with either.

Everyone loves the idea of the 434 with that long 4" stroke, but the extra length of the stroke always makes things much more complicated. My 3.875 stroke engine needed clearance on the Callies Compstar rods, and my solid roller cam only has .630 lift. Will you really know the difference between a 421 and a 434 when the tires are spinning?

rfoll wrote: ↑Fri Jan 10, 2020 10:13 am

Walter R. Malik wrote: ↑Thu Jan 09, 2020 5:36 pm

Monza355 wrote: ↑Thu Jan 09, 2020 4:29 pm


I did think about going with a simple flat tappet camshaft. But i’ Not sure that it fits because of the long stroke because of the base circle.

A flat tappet camshaft lobe is considerably narrower on the flank than a normal small base circle roller lobe.
However, if the rods are not "stroker" rods then there may be an issue with either.

Everyone loves the idea of the 434 with that long 4" stroke, but the extra length of the stroke always makes things much more complicated. My 3.875 stroke engine needed clearance on the Callies Compstar rods, and my solid roller cam only has .630 lift. Will you really know the difference between a 421 and a 434 when the tires are spinning?

Probably not and today i would most likely go with a 421. However the 434 has been payed for so that’s what we have to work with now. And hopefully it will be decent when done.

Well, just decide with how much overlap you can live and you have your duration.


I understand. I mentioned the redline because i want to go to the drag strip on occasion, but since this is primarily a street car good manners, reliability and the fact itmust be able to run on 91 octane pump gas are very important factors of this build. Much more important than maximum horsepower.
[/quote]

Personally ... I would simply get a Lunati "Voo-Doo" hydraulic flat tappet, 227/233 grind with the Victor Jr. intake.
#10120703 ... 268/276 off the seat, .489"/.504" valve lift, 110 separation; 106 intake C/L.
A 1.6/1 intake rocker for a little more lift.

EDIT: There must be plenty of others within the same realm.
[/quote]


I did think about going with a simple flat tappet camshaft. But i’ Not sure that it fits because of the long stroke because of the base circle.
[/quote]

You can get a flat tappet on a .900 BC
[/quote]

Monza355 wrote: ↑Mon Jan 06, 2020 3:23 pm

Is there anyone specific i should talk who can help me out with camshaft for an under headed engine like this ?

Surprised nobody has mentioned it yet...

Speedtalk's very own CamKing of Jones cam designs. He has decades of experience with cams for under headed engines that have to run a spec fuel, compression ratio, lift rule, 2bbl blah blah etc. I doubt the additional cost is much of a factor when you are trying to piece together a combo of parts you already have. This seems like a perfect application for his inverse radius flank lobes to get all you can out of your combination.