CorvetteDave01

Sorry to start another thread, but I really need some input on a camshaft on this motor. Hope I'm not bothering anyone with my posts lately...

I'm trying to get a 600hp ish 427 sbc (Dart block, 10.5:1 compression, AFR 210 Elim heads it looks like at this point, 1.6 roller rockers and stud girdles. I don't drive it much, 1-2 times/week a bit and then I'm going to bracket race it weekends. Ordered a 8-point roll cage for it too already as well as a centerforce dual friction clutch and billet flywheel. Have a dragvette 6-link setup for the 5-speed TKO, heavy halfshafts, cryogenically treated axles and heavy offset trailing arms.

Odd thing is I'm trying to setup my existing Edelbrock Proflo EFI system that is currently on my 383 for this motor. Edelbrock indicates I basically just need a littel port work on the Vic Jr. intake and some heavier injectors, new chip and 10" of vacuum at 1,000 rpm. Possibly could go as low as 9".

OK 2 options for cams I have at this point are...both adjusted already for the 1.6 ratio rockers. I can pretty much do a custom roller of whatever is possible, these are just two options we talked about at the speedshop.
1. 248/256 dur @ .050 640/640 lift, 112 LS (preference)
2. 234/240 dur @ .050 622/624 lift, 112 LS

Any suggestions or comments?

King Lear

need the cfm of the edelbrock proflo, intake centerlines of the cams and rod legnth. I assume you are 4.125 bore and 4.00 stroke. Also need the intake and exhaust valve openings & closings and I can give you an estimate on the desktop dyno program.

CorvetteDave01

No idea on the intake centerline, I just put a couple of options we talked about, I think we can pretty much get a custom roller with whatever specs are possible. Competition cams is the company, I'm pretty sure.

427 sbc will be 4.125 bore, 4" stroke, Scat 4340 crank and 4340 stroker rods 7/16" bolts. Don't know on the rod length, he didn't write it down on my estimate.

Edelbrock proflo setup as original setup on my 383 (original '92/'93 production run, got it when they first came out. New setups have some differences)
1,000 cfm throttle body
27 lb injectors running at regulator pressure 50 psi (looking at 44 lb injectors which should be ok up to 640 hp according to megasquirt calculator)
Edelbrock designed the intake after the Victor Jr. single plane intake good to 550 hp according to Edelbrock, good to 600+ with portwork. The new intakes are good as is for 600+ hp.
Fuel pump good to 625 hp according to edelbrock, not sure on specs off hand on it.
Need new chip burned with new cam and 10" of vacuum at 1,000 rpm, could go 9" they say if I can tune it a bit.
Can get aftermarket software for this setup and burn my own chips, have the link somewhere, got it from Edelbrock efitech line too.
CAN use a solid roller cam fine Edelbrock indicates as there is no knock sensor.

CorvetteDave01

What do u mean on estimate for intake and exhaust valve openings?

King Lear

The seat to seat timing of the cam. I can run the program to find out what exact cam specs will give you the most HP for your engine. It will take a bout 2 minutes and I will let you know what it calls for. Also the dyno program I have has all the comp cams cams already in it.

King Lear

A cam with 640 lift(683 with 1.6 rollers) at 264/264 @ .050 with an intake centerline of 116 and lobe separation of 112 according to the comp cams dyno should give you 621 HP @ 6500 rpm max. and 531 ft lbs of tq @ 5500 rpm max.

King Lear

This comp cam 08-470-8 should give you .640 lift with 1.6 rollers and 600 rpm max @ 6000 rpm and 528 tq @ 5000. reccommends 10.5 cr and 4.10 gears.


Chevy 262-400 Magnum 314HR Cam

GrandSportC3

You need a nice SOLID roller to get that kind of horsepower.. You'll also have to get those heads ported as much as you can. You'll also need at least 10.9 : 1 compression to get anywhere close to 600 HP.
The cam of my old 406 is a Comp Cams solid roller with 264/270 degrees .050 duration and .630 lift (.672 with my 1.6 ratio rocker arms). On my initial build, I had 406 cubic inches, Ported Pro 1 heads with 230 cc intake runners and 11.61 : 1 compression and the initial horsepower with the Victor Jr. was only 558!!! OK, a few more cubes will give you a little more HP and some more torque but it's very difficult to get to 600 HP on pump gas.
My next setup was over 600 HP BUT I had the heads shaved and went with 12.8 : 1 compression and a Super Victor Intake (CNC ported to 1206 gasket).
My new small block (447) should be somewhere in the 700 - 750 HP range BUT I'm going with 14.5 : 1 compression...
As for intake.. The only hood clearance friendly intake that can give you anywhere close to 600 HP is the Victor E intake (2978). Otherwise you will have to go with the Super Victor (2825).
Everything on the combo will have to be ported to 1206 gasket and matched up perfectly!

P.S. The cams that you initially listed will not get you anywhere close to 600 HP.. Especially the 112 LS will cost you HP.. Desktop dynos are usually not too accurate. My initial 406 build made over 600 HP on the desktop dyno but it only dynoed at 558 HP initially.. It's not that easy to make big HP, ESPECIALLY with low compression.. Of course, if you'd go with 18 degree or SB2 heads, you can make well over 600 HP on pump gas but with 210 cc intake runners 23 degree heads, it's VERY difficult to make 600 HP on pump gas.. It is possible but with EXTENSIVE PORTING to intake and heads...

King Lear

I agree with what you saying, but he does have 3.08 gears, you don't think that will cause a problem with a more extreme cam?

GrandSportC3

no problem with the 3.08 gears.. A smaller rear gear will actually cause less stress on axles and rear wheel bearings.... Of course, the acceleration potential with a smaller rear gear is reduced...

gkull

My first 427 motor used AFR 210 heads and 242/248 .620/.620 110 lsa. i figured out that was about the biggest cam i could run with my 10.5 compression

it was actually fun to drive with my 4.11 rear gears and 700R4 tranny with a 3500 stall. From a 25 30 mph rolling start in second gear i could floor it and leave 100 yard twin 315 black strips down the road with clouds of smoke. Then i installed a TKO 600 5 speed and it did not take very long to break the crank shaft

you are not going to make max power with 210 heads, but it will put a big smile on your face If that is what you got enjoy them.

As for the cams "A" is to big and "B" is to small

GrandSportC3

Did you ever have any engine dyno numbers with that engine? Would be a interesting reference for Corvettedave01
I personally believe that 600 HP is very difficult to achieve with 10.5 : 1 compression and 23 degree heads.. Maybe after $1000 worth of porting work, they MIGHT flow enough to get 600 HP but it's not easy..(even though not impossible)

MotorHead

You need heads that flow over 300cfm and solid roller in the 250deg duration, I will make 600HP with the 427ci small block I am building or bust

I do agree it is very difficult and everything has to be right. THis is limit for a 23deg head small block on pump gas

CorvetteDave01

Thanks for all the info guys. Unfortunately, I am stuck with the 210 heads at this point as the order is in and paid for and I really can't afford to try to upgrade it anymore as I'm beyond what I was going to spend already (I'm sure u all know how that goes). So...it looks like I need as high a lift cam as possible without going much over 250 duration? Additionally, I'll get the intake ported, but I may have to be happy for something in the 550 hp range and lots of torque.

I'll look into the couple of cams specs noted Rich and thanks a lot! It would be nice to see what you had in yours George if u could post the specs. What are u doing with your new motor Wayne?

I have been back and forth on the hydraulic roller vs. solid roller cam and could go either way still, I think as the cam and lifters haven't been ordered. How often do solid roller cams need adjusted and how streetable are they? I think I would need some lifters that had roller oiling, if I drive around much around town so I don't oil starve the roller bearings?

CorvetteDave01

I also thought my 1st gear ratio would be fine? TKO 3.27 first gear and 3.08 rearend=close to a 4.11 ratio rearend with a stock 4-speed.

MotorHead

You will be happy with those heads, pretty close to the best you can get in 23 deg. You will have plenty of HP and TQ, I can spin the tires from a 50MPH roll as it is right now with my 406ci. You might want to stay with a low maintainence hydraulic roller such as the Comp 286HR or 305HR I was looking at recently, looks like you could get some good power with those cams. Solid roller has to be maintained and checked all the time. YOu have to keep on it or it will bite you. Lots of fun if you like checking lash periodically and taking the intake off every year to check the rollers, you have to do this or you are looking for trouble.

THe new engine I am building will eventually replace the 406 but I am in no hurry more of a hobby sort of thing, I like to put them together

vetteaddic

I have the 248 ,254 @.050 616 ,622 lift 112ls on my 427 with 230 Dart pro1 ,Professienal products intake,and I think I'm close to 600 hp but not sure, and I think the cam I have is a little tame,and my cam is a solid roller ,been running it for 2 summers with only one time valve adjustment,but is in need of one now.
Make sure you get the small base circle cam and check clearance,(rod to lobe )mine is on the tight side, Comp cams says mine was a small base cam 1.090" ? ......

vetteaddic

Bill Mitchell 427sb claims to get 530hp with their cast iron heads and solid cam and I dont think their heads flow that well and cam isn't big either.

GrandSportC3

I had the same heads (with a lot of porting), a much bigger solid roller cam and 11.61 : 1 compression and only made 558 HP even though all the desktop dyno programs indicated over 600 HP...

vetteaddic

Did you have the heads flowed after porting?
427 or 434 with decent cam and heads should make close to 600hp.