305LG4Cutlass

Think someone could give me a HP estimate and maybe a 1/4 mile time guestimate for the engine I'm building? It's in a Cutlass with 2004R and 3.73 gears. Right now it runs best of 15.5@88mph with the stock LG4 with around 160k miles. Traction might be an issue with the new motor cause it has a little bit too much wheelspin now even with the 305.

It's 350ci, 9.4:1cr, 461 camel humps (202/160 valves) with mild porting, rams horn exhaust manifolds (think I read a while ago that there are 2 sizes, and these were the smaller ones, going to port them some as well), probably a performer intake (going to try and clean up the ports some as well), thinking about a crane cam with 216/228 duration @ .050" and 454/480 lift (unless someone makes another recommendation). Going with 2.5" mandrel bent true duals with H pipe and some decent mufflers (don't know what kinda yet). Does this seem like a decent combo? I'm trying to make do with what I've got, money is really right. Everything is extra parts that were lying around and cost me nothing. All I have to pay for is a used intake, cam, rings, bearings and gasket set. Thanks for any help.

IROCaholic

It would probably make around 330hp with headers but with exhaust manifolds who knows. I also have no idea what cam those specs are for. I would look into one of comps extreme energy cams if I were you. Maybe the XE262. CHP made like 350hp with this cam a performer RPM manifold, Qjet,stock 1.94 and 1.6 camel humps, and open headers. So that may suit you well. But as for what you have now Im really not sure. Good Luck.

Stekman

From what i can tell, that is the H-268 grind from Crane, from their flat tappet Powermax grinds. I believe it is the 272 replacement. Have you done anything to increase the max lift of the cylinder heads? If not, the cam you are looking at is a bit hot for the LG4 (lift wise). The duration is suprisingly close to the Comp 262. Comp's has slightly more aggressive ramp rates, but the difference is small enough that it can be overlooked, for the moment. The lift is the biggest issue. To run the cam you mention, clearance issues may or may not have to be addressed. If you have the means, check the clearance you have now between the guide boss and the bottom of the retainer.

The performer intake is merely a factory replacement. I have a ZZ4 intake that i will be using very soon, i know RB is using them, amongst others. I also have a Performer. Overall, I like the ZZ4 a bit better, and it's still emission legal, if need be. They can be had on eBay and occasionally, in the classifieds on this site.

You are planning on using the factory q-jet right? Might want to have a look to the tech articles on how to modify it for performance.

It's late, I'm running out of suggestions.

zippy

i'd guess dialed in it should go 13.8-14.2. hp wise i'd say 310 or so.

305LG4Cutlass

Okay some adjustments to the plan. Just found out my employee cost at work through GM is $452 Cnd. for a set of brand new assembled Vortec heads. Pretty sure I'm going to go this way. As far as an intake, GM charges up the *** for their Vortec intakes (my cost is $396 Cnd.) so I'm thinking of trying to get a performer RPM vortec (used if possible). Maybe somebody could take a guess at these with 1 5/8" headers and mandrel bent 2 1/2" true duals with no cats and decent mufflers. Compression will still be about the same. I want to shift at about 6000rpm so if someone could recommend a good cam for this setup, I'd appreciate it. I'm not good at analyzing cam lift numbers and knowing whats good. Thanks

Stekman

Are they factory Vortec heads? If so, they are still plagued by the lift issues. In order to use any performance cam with more than .450" lift (number varies, but .450" is the generally accepted value, for the most part, your lift may be more or less). To allow for more lift, the guide bosses need to be milled down. Also, screw in studs are highly recommended.

305LG4Cutlass

They are the vortec heads listen in the performance parts catalog. The lift limit is .475. So I will pick the biggest cam under that limit.

zippy

is this a roller cam engine?

305LG4Cutlass

Nope it's not. It's a 79 block and I don't wanna go through the expense of doing a roller cam.

305LG4Cutlass

bump