Hyd Roller SBC bracket drag car

[65dragster]

A good friend is wanting to move from a solid flat tappet cam to a hydraulic roller cam for his bracket drag car. I suggested going solid roller, but he wants HR. What are the disadvantages of HR vs. solid FT in this application. The car is a 68 Nova weighing 3150 with driver, presently running 11.60’s in 1/4 mile on a 9” slick. Pretty basic forged 350 with 11:1 compression, original Dart Iron Eagle 215 heads and matching Dart single plane intake. Current solid FT cam is .570 lift and 255@.050 duration using 1.5 rockers. The car runs a power glide transmission with 5000 stall and 4.30 rear gears. He is looking for similar performance with a slight improvement (.1-.2) if possible. Will the car lose consistency or have issues with lifter pump up? With good HR lifters, can it still turn 6800 rpm?

[jed]

A good HD roller lifter is the liest of your worries.

[65dragster]

What do you mean?

[paulzig]

Will the car lose consistency or have issues with lifter pump up? With good HR lifters, can it still turn 6800 rpm?

It will only pump up if you put a garbage spring on with low pressure... If you have a quality spring and the valvetrain doesnt get out of control it will never pump up... More like losing lift if anything.

Quality lifters, springs, proper cam lobe selection and your 6800RPM goal isnt an issue...

[Walter R. Malik]

A good friend is wanting to move from a solid flat tappet cam to a hydraulic roller cam for his bracket drag car. I suggested going solid roller, but he wants HR. What are the disadvantages of HR vs. solid FT in this application. The car is a 68 Nova weighing 3150 with driver, presently running 11.60’s in 1/4 mile on a 9” slick. Pretty basic forged 350 with 11:1 compression, original Dart Iron Eagle 215 heads and matching Dart single plane intake. Current solid FT cam is .570 lift and 255@.050 duration using 1.5 rockers. The car runs a power glide transmission with 5000 stall and 4.30 rear gears. He is looking for similar performance with a slight improvement (.1-.2) if possible. Will the car lose consistency or have issues with lifter pump up? With good HR lifters, can it still turn 6800 rpm?

There is simply NO good reason to have any kind of hydraulic lifter in a race engine unless the rules say so.

[Charliesauto]

"There is simply NO good reason to have any kind of hydraulic lifter in a race engine unless the rules say so."

1000% correct.

[DeezNutz]

In an 11 second bracket car there would be no reason to have a solid roller. The HR is perfectly capable of meeting your needs.

[steve cowan]

I think a HR cam will satisfy the needs at this stage but maybe next year you might turn it up, what I mean is you have a big cylinder head for the cubes that could satisfy more hp/rpm especially if using a bigger converter and lower rear gear, with the SR cam you could use most of the valve train and only change cams if needed
There will be a rpm limit on HR lifters

[bob460]

I think there is something wrong with this combo as is...........@3150lb......running 11.6s is only showing 350-360 hp.

If he wants a hydraulic roller, then use solid roller lifters to go 7000rpms.

[F-BIRD'88]

This does not need a new camhaft. This powerglide/350 cid car needs 5.13 gears.. What is the MPH? W i t 60ft ?

[steve cowan]

This does not need a new camhaft. This powerglide/350 cid car needs 5.13 gears.. What is the MPH? W i t 60ft ?

Do you think the cam and valve train he has now will hang in there at 7600-7700 rpm at the stripe with a 5.13 rear gear.
Maybe the guy is on a budget like alot of us.
Before long there will be 10 pages of nonsense and he will need a 3 hp/ ci pro stock engine.

[65dragster]

The car is clearly not optimized. Of course, bracket racing is more about consistency, but everyone likes to go quicker. He is worried about killing the FT cam with today’s oil since he only races 8-10 times/year. Very much on a low budget. 1.7 60 ft times and 115 mph in 1/4. Seems like a lower gear set, maybe 4.88 would help, but he has no interest in running through the lights beyond 7000 rpm. Maybe he’s better off staying where he’s at until he can build more cubes and go solid roller. Dollars add up quickly for a regular guy when you start changing a bunch of stuff. Always appreciate learning from St folks with real world experience. Thanks!

[DeezNutz]

If it's a really low buck deal a good oil will be alot cheaper than a cam swap to any roller set up. With a tight budget, probably just leave it alone and work harder on hitting the tree and the dial in.

[F-BIRD'88]

The exact gear needed will be dependent on true tire height.. The current cam may benefit by moving it.
(Make more torque where it matters)
Agree, get a oil friendly with FT cams.
Not that hard.
Collector extensions and carb spacers can help a lot.
A hyd roller cam swap is going to be $1K.
It would need to make A LOT MORE TORQUE.

With a gear swap, even if you ran the last 200 ft on the rev limiter to control trap rpm, it will ET quicker.
Cal-trac type traction bars work great on these cars.

[F-BIRD'88]

Re: More cubes+ solid roller cam.....
Next time build a supercharged engine for bracket racing.
You can do that with a 350 sbc and hyd roller cam.
And glide with the 4:30's
You will go a LOT FASTER.