Don Terrill’s Speed-Talk

Mike, what is idle RPM for one of those offshore boats?

Rick Finsta wrote: ↑Fri Oct 13, 2017 7:35 am Mike, what is idle RPM for one of those offshore boats?

800rpm

Fwiw, before he passed, UDHarold made me a solid flat tappet lifter copy of CC's great old 288AR solid street roller and gave it to me.

He said that it should hang right with the 288AR and possibly do a bit better.

Spec's are:

278/249/161, 110/106, .618" gross lift and it need's .018" hot lash on both sides.

I bugged Harold for quite a while to make it because I am scared of needle-bearing lifters!

pdq67

I'm going through this lately with street/strip customer engines that will be driven a lot, I have been defaulting to solid flat tappet cams & going up on the rocker ratio.
But the spring pressures we're needing to keep the valve train under control at 7500+rpm are getting scary on an iron flat tappet - 160lb on the seat, 440lb over the nose, .630" lift with 1.72 rocker ratio. So far so good, but I know we're pushing the limit.

Next one I'm going to a solid roller with Cranes street roller .400" lobes, *should* last as long & gain a little right through the rpm range, springs required are gonna be similar (a tad heavier), peak lift will be much the same & will have a little more area under the curve & a little shorter on advertised duration etc, so will idle a bit cleaner.

pdq67 wrote: ↑Sun Oct 15, 2017 11:56 pm Fwiw, before he passed, UDHarold made me a solid flat tappet lifter copy of CC's great old 288AR solid street roller and gave it to me.

He said that it should hang right with the 288AR and possibly do a bit better.

Spec's are:

278/249/161, 110/106, .618" gross lift and it need's .018" hot lash on both sides.

I bugged Harold for quite a while to make it because I am scared of needle-bearing lifters!

pdq67

Have you run it? If you have, or if you haven't and are planning to, what is the displacement of the engine you're using it for? I'm just thinking 0.618" won't be enough.

the first solid roller I did for the street is still doing great! built in 2006, freshened in 2012. just guessing maybe 20,000 miles. LOTS of passes....

Yes a "properly" done valve train will be more reliable!
More area and lift will make more power, so that leaves you with a properly designed roller (hyd or solid) if the goal is max power.

solid roller get my vote,will make more power

OP, how many street miles will this realistically do?

cjperformance wrote: ↑Fri Oct 20, 2017 6:35 pm OP, how many street miles will this realistically do?

Maybe 5k a year

nickpohlaandp wrote: ↑Fri Oct 20, 2017 6:38 pm

cjperformance wrote: ↑Fri Oct 20, 2017 6:35 pm OP, how many street miles will this realistically do?

Maybe 5k a year

You say 521-557 , this makes me think BBF, correct?
Factory block?

cjperformance wrote: ↑Fri Oct 20, 2017 6:50 pm

nickpohlaandp wrote: ↑Fri Oct 20, 2017 6:38 pm

cjperformance wrote: ↑Fri Oct 20, 2017 6:35 pm OP, how many street miles will this realistically do?

Maybe 5k a year

You say 521-557 , this makes me think BBF, correct?
Factory block?

Yes and yes

5k street miles per year in a 521+ inch engine?

After chasing valvetrain issues in my 67 Camaro with a 496 bbc, solid roller with .842 lifters of a few different varieties and stud girdle setup for several years, I now have a new 555 with Morel .903 lifters and shaft rockers. No issues with the new build and it's just a lot easier to keep an eye on valve lash. Time will tell.

nickpohlaandp wrote: ↑Fri Oct 20, 2017 6:52 pm

cjperformance wrote: ↑Fri Oct 20, 2017 6:50 pm

nickpohlaandp wrote: ↑Fri Oct 20, 2017 6:38 pm

Maybe 5k a year

You say 521-557 , this makes me think BBF, correct?
Factory block?

Yes and yes

You're kind of in the area where an appropriate SFT is going to be pushing to last. I'd go SR, but dont even think of the money, lol, you just have to spend good dollars to get a good longer term result.
Spend the money and go straight to .903 lifters, this also allows the lifter bores to be trued up for size and alignment in the machining process, use a street or circle track lobe, ie less harsh on the valve train than a typical drag race lobe. Go as big on pushrod diameter as your heads will allow, good rocker gear and geometry, light (as possible) valves/springs etc all the usual stuff. And the springs must be spot on spec wise.

cjperformance wrote: ↑Fri Oct 20, 2017 7:13 pm

nickpohlaandp wrote: ↑Fri Oct 20, 2017 6:52 pm

cjperformance wrote: ↑Fri Oct 20, 2017 6:50 pm

You say 521-557 , this makes me think BBF, correct?
Factory block?

Yes and yes

You're kind of in the area where an appropriate SFT is going to be pushing to last. I'd go SR, but dont even think of the money, lol, you just have to spend good dollars to get a good longer term result.
Spend the money and go straight to .903 lifters, this also allows the lifter bores to be trued up for size and alignment in the machining process, use a street or circle track lobe, ie less harsh on the valve train than a typical drag race lobe. Go as big on pushrod diameter as your heads will allow, good rocker gear and geometry, light (as possible) valves/springs etc all the usual stuff. And the springs must be spot on spec wise.

Planning on everything you said except for the 0.904 lifters. I was thinking quality 0.875 with a 0.750 roller. Cam will not be overly radical, conservative profile, COMP conical springs, everything else light to keep weight down.

I didn’t think about this until just now, but I bought a really nice borescope yesterday on a whim, so internal inspections will be frequent.