Thread: cam and heads

Tweet

hey guys hows it goin im an 18 year old kid i got a 71 chevelle with a 350 in it its a gm crate engine 300 horse i ran it this summer this winter i am planing on a cam heads and i think an intake im just lookin for some feed back on what im thinkin for a combo first of let me tell you some specs on the engine as it is a 4 bolt main block, cast crank, forged steel rods, cast aluminum pistons,
.435 .460 lift cam 64 cc heads with 1.94 1.50 valves 9.1.1 cr

i want to go with these heads http://store.summitracing.com/partde...5&autoview=sku

this cam

http://store.summitracing.com/partde...5&autoview=sku

one of these intakes

http://store.summitracing.com/partde...5&autoview=sku

or

http://store.summitracing.com/partde...5&autoview=sku


would this make a good combo? will it make my goal of 425 or more hp?

thanks guys any coments will help

THose heads will not do it,the vortecs flow more than they do,only a small amount ,but there half the price.. and the vortecs are good to about 400 hp with a very good tune and bowl work.What are you going to use the car for ,track,street ,daily driver ?I would use the vortecs a rpm airgap and a XE 268 comp cam.a little under 400 ,but it will make lots of torque ,what a heavy car needs to get movin.That cam you showed will not make much torque or hp untill the rpm starts getting pretty high 4500-5000 before the hp would climb above the vortecs,not good for the street, Race track only the team g and big cam might do a little better in the 1/4 ,but not by very much.Usually not many times you can rev to 4000 on the trans brake at the stop light either.The vortecs need new valve springs and some minor work to make them handle a cam with a lift that much over .460

john, I would have to think long and hard about changing the chamber volume. You have the perfect static compression ratio for pump gas at 9.1:1. If you use the World heads with that tiny little chamber (actually designed for the 305 Chevy motor), you'll raise the c.r. to 9.7:1. Now, depending on the squish that Chevy built into the motor when they machined everything, it probably wouldn't run on pump gas any more without detonating and disassembling itself. The other thing is that by raising the c.r., you are changing the cam requirements to a longer duration design, exactly opposite what you want for good street manners. That long cam you have spec'd out will be the biggest pain in the ass you can imagine. No low-end torque without a 3,000 stall converter and very little intake manifold vacuum to operate accessories like power brakes. Furthermore, I would never run a single plane intake on the street. They are meant to be used on a high-rpm motor and won't make enough power down low to move the vehicle without (again) a high stall converter.

Take a look at these dyno-proven combinations and see what they did for parts combinations to achieve the numbers. For a street motor, look for the maximum torque at the lowest rpm's (for instance, over 400 ft. lbs. at under 4,000 rpm's). http://www.ryanscarpage.50megs.com/combos1.html

Originally Posted by shawnlee28

THose heads will not do it,the vortecs flow more than they do,only a small amount ,but there half the price.. and the vortecs are good to about 400 hp with a very good tune and bowl work.What are you going to use the car for ,track,street ,daily driver ?I would use the vortecs a rpm airgap and a XE 268 comp cam.a little under 400 ,but it will make lots of torque ,what a heavy car needs to get movin.That cam you showed will not make much torque or hp untill the rpm starts getting pretty high 4500-5000 before the hp would climb above the vortecs,not good for the street, Race track only the team g and big cam might do a little better in the 1/4 ,but not by very much.Usually not many times you can rev to 4000 on the trans brake at the stop light either.The vortecs need new valve springs and some minor work to make them handle a cam with a lift that much over .460

If you can buy Vortec heads for half the price of the World products I will take 20 sets.
The point I am try to make is I can buy the Dart Iron eagle heads or the Pro Topline heads or World products for around $600 to $635.
Both the Dart and the world heads are better heads overall.
They have thicker decks and come with valve springs good to .510 lift.
The vortec heads are thinner castings and more prone to cracks.
All you have to do is pick a set up and you will tell the difference.

thanks guys for all the help i think i under stand a lot more now also the reason i was goin to go for the world heads is that i can getem real cheap 450 in the boxs

Originally Posted by justmejohn71

thanks guys for all the help i think i under stand a lot more now also the reason i was goin to go for the world heads is that i can getem real cheap 450 in the boxs

For $450 buy them.