[Johnny406]

My 78 T/A is really a STRIP/street car but I'm putting this here with street in mind because the heads up series I race in has us do a road cruises prior to the race and since I have to have the car tagged and insured...might as well drive it locally from time to time.

Ideally, a Hyd Roller would be a better choice but I just don't trust Pontiac hyd roller lifters.

With that said, I'm about to pull and freshen up the 463 in my 78 T/A (see signature). For years I've been running a Lunati VooDoo HFT and I think I've taken the car as far as it's going to go with that combo.

I'm going to install this Ultradyne S/R cam that Paul K sold me a couple of years ago. I also bought a new set of Howards lifters with the direct lube pin oilers and some Howards springs to match the cam 180/465lbs.

With the direct pin lifters, can/should I still install restrictors and/or restricted pushrods?

For heads up racing, I am about .3-.5 in the 1/8th mile slow from being very competitive. I run a 160 shot now and I don't want to spray anymore than that as I have a 2 bolt block. On this freshen-up, I am going to install main studs to help it a bit. Realistically, will the cam change as well as bumping up to a Victor and 950 carb get me there?

[Gach]

Paul would be the guy to suggest whether or not you should run restrictors with that cam.

[JLMounce]

How much actual street time will the car see? I don't know how long or often the mandatory cruises are in your series. If it's a good bit of street time, I know that a lot of the drag and drive guys don't restrict at all. They flood the top end to keep things cool up there.

[Johnny406]

Originally Posted by JLMounce

How much actual street time will the car see? I don't know how long or often the mandatory cruises are in your series. If it's a good bit of street time, I know that a lot of the drag and drive guys don't restrict at all. They flood the top end to keep things cool up there.

Hey Jason, are you coming down to PMP this year? I'm doing the Steel City No Prep series that Donny and company hosts. Not a lot of street time, the last two road test I did were about 22 miles (10 laps) on the Pueblo Motorsports Park road course. I wouldn't be using this car for Rocky Mountain Raceweek.

[JLMounce]

Originally Posted by Johnny406

Hey Jason, are you coming down to PMP this year? I'm doing the Steel City No Prep series that Donny and company hosts. Not a lot of street time, the last two road test I did were about 22 miles (10 laps) on the Pueblo Motorsports Park road course. I wouldn't be using this car for Rocky Mountain Raceweek.

Possibly. It's quite a drive to get down there for just a few trips down the strip. I've been wanting to do RMRW. But I don't know if it's scheduled to hit PMP, at least in the first outing of the year.

With Bandimere shut down, who knows though.

If you're just doing a couple slowish laps around the road course, I think you'd be fine to restrict, at least some. I don't know what pushrods you use, but I believe smith bros stuff can be had in a variety of sizes. Maybe skew a little towards less restriction, knowing street miles may occur?

[Steve C.]

Almost 30 years ago I used a UltraDyne solid roller cam in a 412cid combo, it had a bit less intake duration than you intend on using with 251 degree sat .050". But it also had a 108 LSA. The lobe lift was .3883" with 1.65 rocker ratio.
The iron d-port heads had less flow at about 280 cfm at .600" lift. The compression was 10.79:1. It used a modified Performer RPM intake. The combo made peak power at 6400 rpm on the dyno.

I only bring this up because of your intended spring pressure. Just a tid bit for reference here, not necessarily a recommendation over your intentions.
But If memory serves me correctly we were using about 210 lbs seat pressure to control the valves. Sorry I don't recall the open pressure. This a recommendation from Harold Brookshire at the time.


.

[blueghoast]

I run a solid roller once without restricters and kicked a rod out on the dyno.
I won't run a solid anything without some kind of restricters.

GT

[Jay S]

I found that those particular lifters don’t have much for metering the oil to the top end compared to other brands, they will flood the top end with oil. I tried running them with no restrictors and I had trouble. After a full throttle blast or constant RPMs, getting back on the throttle the oil pressure would not recover very well, like the pump was sucking air. Was pretty nerve racking. That was with a 7 quart oil pan and iron heads, which don’t usually have problems with return oil. I restricted the lifter bores with .040”s and the problem when away.

Restricting the pushrods on a SR cam that runs lash you end up spraying extra oil back into the rotating assembly. Especially when the oil metering in the lifter isn’t great. I am sure it still gets plenty of oil to the top end for drag racing. A HR lifter is pretty much coupled up to the pushrod all the time, it would provide more oil the the top end than a SR lifter with the same restrict pushrod. Personally I think restricted pushrods aren’t a great idea on street engines with SR cam, designed more for HR setups. Those lifters need restricting though, restrict pushrods would be better than nothing.

[chuckies76ta]

Any chance you could post the part number for the Howard lifters? Thank you.

[Johnny406]

Originally Posted by chuckies76ta

Any chance you could post the part number for the Howard lifters? Thank you.

Gladly, here you go.