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Author Topic:   flat tappet vs roller cam HP - for the engine builers...
BrianW
Dirt Freak

Total posts: 385
posted December 14, 2004 03:55 PM  
Ok - I've been debating on the roller vs flat tappet setup for a while, when you add up all the extras for a roller setup that really eats into the budget...

I know that I can run a more agressive lobe profile, etc on a roller but My question is what is the real world HP difference between the two and does anyone have a recomendation for either cam (flat or roller) for the following combo:

406, light forged flat-tops, 6" H-beam rods, 4340 eagle or scat crank, 49cc iron eagle heads - 215cc runner ~13.5:1, I've got a super victor intake and C&S billet aresol carb that I'll top it with.

iowatoolman
Dirt Freak

Total posts: 369
posted December 15, 2004 10:48 AM  
i have been running rollers and can get the cam and lifters for about 350-400$

let me know

drive hard or drive home

i ran one in my 406 last year 2bbl motor and did better than a guy with a 383 in a mod
(i run figure 8's)

let me know

BrianW
Dirt Freak

Total posts: 385
posted December 15, 2004 03:47 PM  
quote:
Originally posted by iowatoolman:
i have been running rollers and can get the cam and lifters for about 350-400$

What brand of cam and lifters are they? What type of lifters (vertical or horizontal bar? solid or hydraulic? Also - what grinds / base circle options are there? $350 sounds cheap, I'm looking at $220-250 cams and $230-250 for lifters, then add in the short pushrods for the retrofit lifters and better valvesprings, better valves.

mod_racer98g
Dirt Roller

Total posts: 25
posted December 28, 2004 02:29 PM  
Buy a Doug herbert performance cam shaft i've had super luck with my roller and u can find lifters for around 200 $$ and don't forget the rev kit for it. I went from a roller to solid cam and have had nothing but oil troubles.

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted December 28, 2004 03:01 PM  
The roller will make more power, but like you said it hurts the wallet a lot more too. It will also make the engine act like more of a brake when off the gas, which can help slow the car into the corner, if you need it. Some of the flat tappets are pretty aggressive and you can make great HP without going to the roller. If you wanted you could have your block machined for ford lifters which allow you to run an even more aggressive lobe safely. Combine that with 1.6 rockers and you valve action is getting quicker more like a roller would be. Either way i would make sure you use the EDM oiling lifters.

Assuming alcohol fuel for a flat tappet I'd look at something around 260-262 intake and 264 exhaust. Also I'd prob run 1.6 rockers on the intake at least if not all valves. Isky makes one 262/264 .580/.590 w/ 1.5 rockers. Reed makes one a little less aggressive but prob easier on parts thats 260/264 and would be around .555/.565 W/ 1.5 and .590/.600 with 1.6 rockers.

[This message has been edited by dirtbuster (edited December 28, 2004).]

Kromulous
Dirt Forum Champ
Total posts: 796
posted December 29, 2004 06:47 AM  
Rollers will make more power, period. More RPM amd less valve train failure. Flat tappets are hard on things in my opinion. Plus the wear really fast, lifters as well as the cam.

Also you can interchange cams without changing lifters with a roller cam. Small bonus but you can do it. Swap cams in and out till you find what you like.

Cams it doenst much matter, long as there steel and machined good. Roller lifters are a different story, buy good ones. Comp Cams, Crower or Jesel, the jesel's require aditional machining but are trick. Isky makes some nice ones as well.

In the end rollers are probaly cheaper, considering wear and other things such as failures. Plus there cool, LOL.

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