cam question for 89 tpi 350

[jason-1995fbody]

ok my question is will a flat tapet cam fit in my roller block
i know i will have to change the springs and lifters but a flat tappet is only 100 bucks and a roller is like 200 so what do you guys think will this swap work

[wrightz28]

I wouldn't do it.

The roller costs that much because it lasts allot longer. Have you spec'd the original to verify it is bunk?

[jason-1995fbody]

no but it is stock and i want to go bigger

[wrightz28]

put in hotcam

[corning_d3]

A roller cam requires new roller lifters, also..

[jason-1995fbody]

? 200 plus for a roller cam only or 100 for cam and lifters flat tappet im on a tight budget

[TEXAS-HOTROD]

The hot cam would be a good choice and you can reuse the roller lifters. Roller lifters don't don't create any wear patterns, so it doesn't matter. You're making a big mistake by degrading down to a dinosaur cam.

Have you upgraded the exhaust system? Headers? Have you done any computer mods? What about SLP runners and swapping to 1.6 rockers? You get more valve lift by using 1.6 rockers. The factory roller cam gives more valve duration than a comparable old school set up anyway. Swapping rockers is easier than swapping cams.
You still won't gain much unless you install a better set of heads (A.F.Rs. are the ultimate). So don't expext big gains.

[jason-1995fbody]

sorry i guess i should have said the motor is tore down and out of the car
i have done some port work on the intake and the heads this is time consuming due to my budget wife and two kids

and yes i have headers the rest of the exhaust is stock bbutt that will go
also flat top pistons are going in

[corning_d3]

Originally Posted by TEXAS-HOTROD

The hot cam would be a good choice and you can reuse the roller lifters. Roller lifters don't don't create any wear patterns, so it doesn't matter. You're making a big mistake by degrading down to a dinosaur cam.

You can't use roller lifters on a hydraulic cam.

[Morley]

Originally Posted by corning_d3

A roller cam requires new roller lifters, also..

No, it doesn't. The flat tappets had to be replaced because of the wear pattern they got on them from the current cam would destroy a new cam's lobes. Roller lifters don't get any wear pattern on them because they have rollers.

[corning_d3]

Believe me, they do. A roller cam has a flat profile for the lifter to ride on. A hydraulic cam has an odd profile so it can spin the lifter. Believe me, they can't be interchanged.

[Morley]

Originally Posted by corning_d3

Believe me, they do. A roller cam has a flat profile for the lifter to ride on. A hydraulic cam has an odd profile so it can spin the lifter. Believe me, they can't be interchanged.

No, you don't have to change hyd rollers when you put in a new hyd roller cam in it. But if you change flat tappet cams you must put in new flat tappet lifters each time.

[TEXAS-HOTROD]

What's the deal? Is there some confusion here on which cam is what?

There are flat tappet cams and there are roller cams. We all can relate to what the difference is, right? Flat tappet lifters cannot be reused on a different cam nor can they be swapped to a different lobe location. Roller lifters can be reused and installed on different roller cams as long as the lifter its self is in good mechanical condition.

"Mechaincal" or solid lifters don't have a provision for hydraulic self-adjustment and have to be manually adjusted. They are more suited for racing application and/or for high rpm use. There are mechanical flat tappet designs and mechanical roller designs.
Not to create any more confusion here, mechanical lifters can't be used on a hydraulic cam (whether it's roller or flat) and hydraulic lifters can't be used on a solid grind cam.



Jason was referring to the hydraulic type in his original post. So for a no-brainer answer: IF YOU CAN'T AFFORD A BETTER ROLLER CAM, STAY WITH THE STOCK ROLLER CAM!!!!!!!!!!!!!!
There are other less expensive mods you can do that will have good results.

[jason-1995fbody]

but for the price of a roller cam i can get a flat tappet (hydraulic) with lifters springs and cam

[TEXAS-HOTROD]

Sure, go ahead and put in the cheap Chinese parts.
It won't be such a good deal when you have to pull it back down after the cam goes flat.
If you're so stuck on a flat tappet, get quailty parts. At least spend a few extra dollars and purchase a Competition Cams kit.
If you run a flat tappet cam, use Shell Rotella T oil. It has addatives for diesel engines that are better for the cam's lobes. The regular "over-the-shelf" oils are formulated for rollerization and have fewer addatives that the old-styled engines need.