roller motor or flat tappet?

house

house

the Fat kid!
Joined
Apr 23, 2006
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I am putting a 12 valve in the ford over the winter...
trying to decide to be competitive in a 2.8 class if i need to justify spending the extra and going roller cam over a flat tappet
 
house said:
I am putting a 12 valve in the ford over the winter...
trying to decide to be competitive in a 2.8 class if i need to justify spending the extra and going roller cam over a flat tappet
Click to expand...

Alot of your best super street trucks run flat tappet. Don't think that will be your make or break point. I would put that money elsewhere into the build.
 
house said:
I am putting a 12 valve in the ford over the winter...
trying to decide to be competitive in a 2.8 class if i need to justify spending the extra and going roller cam over a flat tappet
Click to expand...

abandoning the 7.3 eh?
 
Flat tappet will work well, if you have the money go roller, you can run higher spring pressures with the roller, but make sure you have a good quality valve to get it done. Roller is more durable in my opinion.
 
I see SmokinCummins posted a pic of my cam. Ill post it here as well. With the came staying open quite a bit longer than normal and the big inconel valves to go with it. You can really move some air and are open to a very wide range of chargers.
 
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2Tone12V said:
I see SmokinCummins posted a pic of my cam. Ill post it here as well. With the came staying open quite a bit longer than normal and the big inconel valves to go with it. You can really move some air and are open to a very wide range of chargers.
Click to expand...


Combine that with a well ported head, higher ration rockers, and a nice IR intake, you have one freaky nasty engine.$.02
 
2Tone12V said:
I see SmokinCummins posted a pic of my cam. Ill post it here as well. With the came staying open quite a bit longer than normal and the big inconel valves to go with it. You can really move some air and are open to a very wide range of chargers.
Click to expand...

Alot of the lobe width is cause it is a roller, the roller allows for steep ramp rate, but also requires a wider lope to be able to have the same valve motion.
 
All depends on what kind of $$$$ you want to spend. Rollers are better as far as the other things you can do to go along with them. But they come with a price tag. Your call man. But unless your going to do everything I would stick with the flat tappet.
 
Roller now will make it so that you can upgrade other things later. Roller in theory should always make more power. Roller would be my vote. Good luck.
 
I have seen some engines that compete at the top levels of diesel motor sports that were flat tappet and roller. Flat tappets have positive attributes as well as rollers. Factor in the law of diminishing returns and the flat tappet starts to look pretty good as far as hp per dollar spent.

Just putting a roller in will not give you extra horsepower. Having a well thought out roller cam cut that works well with your other modifications to solve a problem you are having with your current valvetrain or airflow at high rpm and yes you will see gains. The dollar per extra hp gained will be very high. I would only do this if you were competing against the elite in diesel. And I would only buy one that has been proven by the big boys. In other words, get out your checkbook and be prepared to spend some money. Remember the billet core or the roller tappets have no intrinsic value, it is the intellectual property involved in the profile design that takes advantage of the potential benefits that rollers can provide that has value and extra hp potential.

Zach
 
Hamilton Cams said:
I have seen some engines that compete at the top levels of diesel motor sports that were flat tappet and roller. Flat tappets have positive attributes as well as rollers. Factor in the law of diminishing returns and the flat tappet starts to look pretty good as far as hp per dollar spent.

Just putting a roller in will not give you extra horsepower. Having a well thought out roller cam cut that works well with your other modifications to solve a problem you are having with your current valvetrain or airflow at high rpm and yes you will see gains. The dollar per extra hp gained will be very high. I would only do this if you were competing against the elite in diesel. And I would only buy one that has been proven by the big boys. In other words, get out your checkbook and be prepared to spend some money. Remember the billet core or the roller tappets have no intrinsic value, it is the intellectual property involved in the profile design that takes advantage of the potential benefits that rollers can provide that has value and extra hp potential.

Zach
Click to expand...

I think you basically just repeated what I just said. But with 50 more words.LOL
 
You were right on, I just elaborated on your statement in more detail.

If you are going 2.8. I think you can do VERY well in that class with a flat tappet. I would take the extra money and spent it on the head, springs, valves, external gate, and other important items. Having your head flowed and having a cam that has enough lift to take advantage of the port job and then the duration required to turn your required rpm will give you an edge.
 
When you says the roller is more money I assume most of the money is in the machining. The cam, lifter and push rods cost about the same flat or roller.
I know you should bush the cam bearings but do you need to bush the lifters or can you just machine the lifter bores.
 
I know folks who do not machine the bushings for the roller and no issues so far.
 
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