[BMFH]

Hello All

Yet another cam selection question:

I am not that good in selecting cams, especially roller cams.

I also plan on installing Rhodes lifters to help with the street manners too.

Trying to figure out what type of roller cam to install in my 455.

It will have 670 heads, approx 11-11.5 CR, flat top pistons with only the 2 valve reliefs.

I would like something comparable to the 068 flat tappet cam, only in a roller cam.

Not trying to get a max performance 455, just want one that will run well and have some decent street manners, and some stip time once in awhile too.

The car will be a 70 Firebird with a 4L80E Over Drive Transmission and probably a set of 3.08 Gears and a Posi.

Also what RPM stall converter would work best in this configuration?

Any help would be greatly appriciated, you guys are the experts in my book since alot of you race the ole Pontiac's, and build a varity of street Prefomers.

Thanks in advance for any help on this.

Take Care,

Dusty

[rexs73gto]

1st off does Rhodes make a roller lifter , & if your only going for a decent street mannered car why are you going with a roller cam. You can get all you want with a flat tappet cam & something like a 744 cam which is a great overall cam for street & use on the strip every once in awhile. Going roller is just going to add a lot of extra cost going that route.??

[78w72]

rhoades does not make a roller lifter, the rhoades lifters you are refering to that "help with street manners" are strictly hydraulic flat tappet lifters.

if you want to take out the guess work, call or email SD performance. they have many tested & proven roller cam options that will work for your needs. probably the "stump puller" will be best for your needs.

yes roller cam set ups are expensive, the cam is about $300, roller lifters are $400+ & you need a special $50-$100 distributor gear. & probably new valve springs but they arent that expensive, probably $100-$150.

a roller cam will be about $1000 +/- but it will reduce friction & free up some HP, also dont need to worry about cam break in & special oil or additives. so its your choice but as mentioned above, for a mostly street car at lower power levels it might not be worth the investment.

that being said i love my "old faithfull" roller from SD, idles great, plenty of vac for power brakes, & huge power band when you get into the throttle.

[superdutybob]

I'd be much more worried about where to buy gas for an 11.5:1 iron headed engine.

[Norwood]

Originally Posted by superdutybob

I'd be much more worried about where to buy gas for an 11.5:1 iron headed engine.

LAX would be my guess

[indymanjoe]

Pontiac airport...

[Sirrotica]

Originally Posted by 78w72

rhoades does not make a roller lifter, the rhoades lifters you are refering to that "help with street manners" are strictly hydraulic flat tappet lifters.

Rhodes does make roller lifters, but not for Pontiac/Olds V8 application.
LS series, SBC, BBC, 3800 Buick, and Iron Duke, some fords and chryslers.

Look at the bottom of this page, roller lifter pictures and applications are listed:


http://rhoadslifters.com/sc2/agora.c...x_Flat_Tappets

[78w72]

sorry meant for pontiacs, in reply to the engine he was asking about.

[1971455HO]

Hello BMFH,

I'm ex military, went in country 45 years ago. Rode on PBR's. Didn't stay as long as you did. I saw you retired from wrenching H-53 helicopters in 'Nam, Laos, etc. Glad ya made it, thanks for your service. I picked up on your handle B.M.F.H. it made me laugh. Reminded me of B.B.M.F.I.C.

Back to Pontiacs... A lot of guys here do run roller camshafts in their Ponchos. They have their reasons, I'm sure you do too. I feel foolish telling a guy like you that he might want to reconsider compression ratio a little bit. 11.5:1 is a bit stout for an iron head street engine unless you have deep pockets for racing gas all the time. Those 670 heads will be a tight squeeze on a 455 engine. They're just 72 cc heads. You need some big time octane if you are gonna run them. I think a bigger volume head is the right way for you to go. A set of aluminum Edelbrock R/A IV round port heads would be a better choice for you @ 87 cc chamber volume than the 72CC 670 heads. Your end C.R would still be at about 9.9:1. That's not a problem with aluminum heads though. Quicker heat dispersment and if you run a cam with a little longer duration, that will make it even better.

A roller cam will get you away from having to add additive to the oil for lobe protection and there's no break in. There is a higher cost that goes with them. No matter what cam you decide upon, that high compression number you stated earlier needs to be considered.