I am looking to rebuild a motor, and when it is all ready prep the car then drop the motor in, but i am having a hard time figuring out whether to go with hydralic flat tappet? or hydralic roller? I guess what i am asking is what are the pros? and what are the cons? what is good bout them and what is bad? what power range are they more effective at? any help would be appreciated. It is a tuned port injection motor ill be building i want at least 390-450 horses post links do whatever just help me get out of this decision

Roller cams are far superior because they increase angle (steepness) the closing and opening ramps that have to be ground into a flat tappet cam to prevent lifter’s from jamming up in the first place. Roller lifters can take a steep ramp because of their wheel design. Once a valve reaches 0.300″ of lift (valve lift, not cam lift) it is less restrictive to air flow. So the intent is to get the valve to max list ASAP so that it can be less restrictive. This increase air flow, which in turn increases power and economy. VVT systems take advantage of what we learned by using roller cams. A roller cam’s duration is measured at the same points as a flat tappet cam. SAE standards start duration measurement at 0.006″ of lift. Whereas racing cams often start the duration measurement at 0.050″ of lift. If you compare the two cams in the picture above they have approximately the same duration. Duration is technically defined as the amount of time the valve is open (just time, not airflow, lift, etc.). So with equal lift and duration the roller will still make more power because of the steeper angles.




Seeing as your car is an 89 it's already a roller don't go backwards and put in a flat tappet unless your on a serious budget.

well this is the situation i bought the car and it did have a roller 350 in it. I was a newb and didnt no i replaced headgaskets and all, a week after buying the car. A week after i got it running again the motor stalled and when i started it back up it was knockin pretty bad. So i got a 350 flat tappet for 575 with intake and everything so i did go backwards now i regret that decision and am tryin to find an easy way out but feel i should buy a roller motor and junk the other or sell

i got a ? for ya man. let say i wanted to put to top end of a 89 roller cam motor on my 85 oldstyle 350 would that work?

The top end as in heads? Yes, it will all swap out.


Roller or nothing for me, i refuse to use flat tappet. It is a PITA to have to break a FT cam in right and make sure you are using the oil with ZDDP that keeps them alive.

Z

Not all roller lifters are the same. I just finished some work on a 350 Vortec engine and was looking at the lifters. The lifter design around the roller doesn't allow for a very aggressive ramp design. When buying a roller cam, make sure it will work with factory roller lifters or you'll need to buy better aftermarket lifters.

Roller lifters are very forgiving. You can pull them out and put them back on whatever lobe you want. Unlike a flat tappet lifter, they don't wear into any specific lobe.

You can buy used roller lifters or a used roller cam and mix and match components. You can put used rollers on a new roller cam etc.

If you buy a used flat tappet cam, you either need the exact lifters that were used and need to know which lobe they were on or you need to put new lifters on the cam. Used flat tappet lifters are garbage and should never be reused. New lifters on a used flat tappet cam will not hurt the cam.

Roller is just so much easier. Less wear, less friction, more aggressive ramp designs just make it a better choice.

Is the flat tappet engine machined for roller lifters?
GM put flat tappet cams in a lot of roller blocks in the early '90's; mainly in trucks and vans. If so the roller cam is a easy swap using cheap factory parts.

To fit rollers into a early non roller block is relatively expensive because the retrofit rollers are $$$

rollers are great if your pocket is deap enough. ive seen some veryyyy badass flat tappet motors though.

Well, this one is priced right, was 149$ but just went up with the trash obama...i mean economy...

http://competitionproducts.com/prodi...p?number=E1135

Flat tappets are so out dated that oil manufacturers aren't even making lube to support them anymore.

Would that cam work with stock roller lifters

I love it when people come into forums and talk **** bout flat tappet. GM made it and they have made some great numbers and got used where we are at today in cam and valve train tech so if you were to take that huge year span where the flat tappet rained and saying that is a waste you can go **** youself cause they make great numbers, IF you no what your looking for and know what you are doin that is all thank you guys for the answers i appreciate it and they are TONS of companies that make lube like everyone of them so no your **** befor you talk it **** thanks

I dont really see anyone trashing flat tappet so i will assume this is directed at me. You might have been a newb to the world of mechanics when you joined this board, i am not.

Flat tappets can make great power. I personally put a new cam and lifter kit in my 350 just this year from comp cams and it works great for my app. But that doesn't change the fact that oil companies aren't putting enough zinc in their oil anymore to support a flat tappet cam. That is just a fact. Comp cams now reccomends using a bottle of break in lube every oil change or thier new oil or any speciality oil like Joe Gibbs that is specifically desiged for use with flat tappet cams.
If you want to use off the shelf oil you are going to be using a diesel lube.

I dont think anyone is trash talking flat tappets but roller technology is much better or else they wouldnt continue to use it.

Nobody's even mentioned Nascar and what there using at 850+ hp
and pushing 9800 at some tracks for up to 600 miles and on it


Later