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-   -   Solid flattappet vs. Solid roller (http://www.hotrodders.com/forum/solid-flattappet-vs-solid-roller-184098.html)

Johan Lokander 09-08-2010 02:50 PM

Solid flattappet vs. Solid roller
 
Hello.I have no experiens on Roller cams, so I wold apretiate som help on the subjekt.

Im about to bye a Chevelle -70 whit a 454"(.30" over) whit a solid flat tappet cam.Unfortnitly I havent the specs on the cam at the moment, but its a farly mild cam, the engin dont make powe over 6000rpm and the car sems cuite streetabil.The engin have made 537hp on a dyno.

The Car have ben used whith 200hp Nitrous on the strip, but sens I dont have anny experiens on Nitrous (either) and dont planing on drive mutch on the strip, I wold rater have some more hp in the engine, if I culd get some whitout sacrifice driveabillity, and dont use the Nitroz.

The specs on the engin I know at the moment are Edelbrock heads, Weland 2 plane manifold, Holly 850dp, MSD 6al, Hooker 1 7/8 headers and 3" exaust whit X-pipe.
The car has 3.90:1 in the axel and stock chassie (accept diffrent controle arms and shocks etc.).At the moment it has 275/60-15 M&H radials but I probobly get some 28" high and as whide as fits slicks or DOT tire that i can use when Im in a hurry...

Anny way, If I understan corektly, I culd gane som power whitout sacrifise drivability whit a roller cam.What wold be a good roller came to this cobo and how mutch more power wold I likely gane?
Wold anny of thise be a good candidate?
http://www.compcams.com/Company/CC/c...?csid=498&sb=2
XR274R

http://www.compcams.com/Company/CC/c...?csid=499&sb=2
XR280R

If its anny world you dont understand, dont hasitate to ask!

lmsport 09-08-2010 04:37 PM

537hp out of a streetabil 454 is good and I dont know if I would bother changing anything.

You need to check piston to valve clearance if you change the cam.

I would choose the 274 R if I was to pick one.

Chris Kemp 09-08-2010 04:44 PM

I think I would leave it alone. 537 hp the way it is ain't bad! A roller would give you a little more but would it be worth pulling the radiator, water pump, manifold, distributor and all else that is required. Street-able big blocks don't make much power over 6000 rpm anyway. If you really are serious about this then check with any of the popular cam shaft companies. They all have great tech advise and can help you pick a cam. The only down falls to the solid is that it can't take the higher revs as good as a roller, the valve lash needs to be adjusted more often and they are little noise. IMO and in an older muscle car the clacking noise of the solid cam adds to the car.

Chris Kemp 09-08-2010 04:52 PM

Quote:

Originally Posted by lmsport
537hp out of a streetabil 454 is good and I dont know if I would bother changing anything.

You need to check piston to valve clearance if you change the cam.

I would choose the 274 R if I was to pick one.

Yeah I forgot to mention valve train interference problems that you may run into such as: valve to piston, rocker arm to stud and spring binding. Leave that big ****** alone and let her eat! Measured on a dyno that was probably at the rear wheels, 537hp is real good. That means it could be making as much a six hundred at the flywheel. Not bad not bad at all! Post some pics if you can!

Johan Lokander 09-09-2010 11:22 AM

Quote:

Originally Posted by Chris Kemp
Yeah I forgot to mention valve train interference problems that you may run into such as: valve to piston, rocker arm to stud and spring binding. Leave that big ****** alone and let her eat! Measured on a dyno that was probably at the rear wheels, 537hp is real good. That means it could be making as much a six hundred at the flywheel. Not bad not bad at all! Post some pics if you can!


Well, removing the radiator, waterpump and timing cover isent mutch of a problem.Regarding spring binding I think Edelbrock say max .700" lift on the heads, but of cours Im planing on use the corekt springs for the cam annyhow...Rocker arm to stud interferenc shuldent be a problem sense the engine has roller rockers, but of cours Im cheking that if I change cam.

Yanking of a head to check piston ot valve clerens isent mutch problem eader if I have to, we have looong vinters in Sweden! :D
But now that I think about it, cant I just to turn down the rockers so that the valves is held open on the cam base by as mutch as the minimum of valve-piston clerens, and then carfully turn the engine?If the engine turns over 2 revs, the clerens have to be good?? :pimp:

Im pretty shore the 537hp is in the engine.Closer to 600 is more what Im looking for :)

What I whas wondering is more or less what performance gane I culd suspekt if I change a solid flat tappet to a solid roller whit about the same low rpm street manners.
If its 10-20hp, then I dont think I think its worth the monney and effort, but if its 50hp I think it is :evil:


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