hello new to this forum.

i building a 427 sbc with afr 227 eliminator heads with 1.6 1.5 rockers
900 prosystems carb on a spier racing ported super victor intake.
going to have around 11.1 to 1 compression with je super lite pistons that are dished couldnt use inverted dome couldnt get enough cc out of them. i didnt want to go this way but allready had the heads. its a spherical dish pretty nice piece. 4 inch stroke 6 inch rod. 22 24 endgaps on rings
turbo 400 tranny dont know stall yet unti i dyno the motor
410 gears.
this is going in a 1970 camaro thats still pretty heavy thats going to be a street strip motor mostly strip last motor saw 4000 miles in 3 years
i need some help with camshaft selection i always get in wrong and i think cam companies allways undersize.

i want to run solid roller always have on the street no problems using lunati pressure fed lifters. springs are 235 seat nextek springs
can anyone help on cam selection for me. i was looking at the lunati voodoo line 255 263 @ .050 640 600 lift on a 110lsa. part #60134

do ya think i need larger or differnt lsa.

i want good power but like the rougher idle and i dont think this cam will give it to me unless i ground it on a 108lsa.

i hate cam selection drive me nuts its the heart of the engine.

my last cam had a comp big mutha thumper man did it sound good but not real good on power im use to solid roller motors. i dont want to spin it more than 6800 maybe even lower i need good torque to get this car going.

this is the biggest cubic inch i have built and not sure how much it will eat up the camshaft size. hope ya can help thanks

For under 6000 RPMs?

Everything about that combo looks pretty well matched except your expectations of topping out at only 6000. It'll pull well past that, even feeding 427 cubes. You could knock an easy 10* off the duration and still have a combo that's going to pull hard well past 6000.

For under 6000 RPMs?

Everything about that combo looks pretty well matched except your expectations of topping out at only 6000. It'll pull well past that, even feeding 427 cubes. You could knock an easy 10* off the duration and still have a combo that's going to pull hard well past 6000.


thanks for replying not sure where you got 6000. i said 6800 but to your answer i got it that cam should pulll pretty hard good to know. thanks

I would say that duration will peak on the dyno about 6500. So shifting at 6800 is about on target.

glad to here that do you think the 110 lsa or 108 lsa is the way to go

You won't be able to tell the dif. You have enough compression to go 108 and it should pull better once on the cam.

thanks for replying not sure where you got 6000. i said 6800

I need glasses. For real.

That cam looks to be the old UD Harold cam.I think it's one of his favorite all around cams.That cam is made on 3 different lobe centers. http://www.lunatipower.com/Product.aspx?id=1995&gid=290 is on 110.
http://www.lunatipower.com/Product.aspx?id=1980&gid=286 is on 109
http://www.lunatipower.com/Product.aspx?id=1941&gid=275 is on 106
Harold himself has said with the last cam in a 383,with 11 to 1 comp and AFR 210 heads,the engine made well over 600 HP.I'm looking at the 109 for my 385.

Here is some good info.
http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/index.html
This page has what you want.
http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/lca_selection.html

Tighter LCA's more low end power Wider LCA's more topend power. With that said a biggie engine can stand a wider LCA you would still make plenty of power with a 112 LCA over a 108 and have a much better idle too.

In theory wider carries the power further but that doesn't mean it would make more. It just MAY not fall off ther cam quite so fast. All those articles are so generic they basically are nearly worthless.

Agreed with Rick, widening the LSA can actually cost power.

Tighter LCA's more low end power Wider LCA's more topend power. With that said a biggie engine can stand a wider LCA you would still make plenty of power with a 112 LCA over a 108 and have a much better idle too.

It depends on the cubic inches.

Years ago one of the rags did a dyno test with 3 camshafts identical except for LSA. iirc they were on 108, 110 and 112 LSA's on the same engine, a 355 ci small block built by Grimes. The 108 made the most power all through the power band right to the top of the useable RPM range, followed by the 110 and then the 112.

Vizard says the basic rule of thumb with small block Chevrolets is, the larger the engine, the tighter the LSA needs to be for max power and torque. For example, he mentions that, generally speaking, a 283 prefers camshafts on a 112-114 LSA, a 327 on a 110, 350 on a 108, 383 on a 106, 400 on a 104, etc. His reasoning relates directly to efficient cylinder filling --- intake valve diameter vs. volume of the cylinder. The larger the cylinder the quicker the intake valve needs to open.

You are right Dirt, Widening the LCA will cost power but on the street I don't think it's that big of a deal with a 427 ci. engine. I have read that most Big Blocks prefer a LCA of 112 to 114 but the heads on a BB flow very well.

I would say that if street manners are more important that max power than I would stay on the wider side of things. I guess it's all up to the indivdual and what he plans to do with the engine.

I know one thing My good friend's LS1 has a Z06 cam that is on a 117.5 LCA and that thing pulls like a train and runs high 11's

I had a 454 Big Block one time with a GM 6209 Marine cam that had a 116 LCA and that would spin to 7k with ease and it was a hyd cam too boot.

Right, BBC heads and LSx heads flow very well compared to most 23° SBC heads, and thus those engines work very well with wider LSA's.