New To Here. Looking For Advice On A 4.6 2v Build

[Eric22ff]

Hello there everyone my name is eric and I am seeking advice on a build I am looking to do, bare with me as this may be a lengthy and detailed post of what i currently have and where I want to go with it.

I currently own a 1996 Gt 4.6 2v. It has forged internals with K1 connecting rods and Weisco pistons ( minus a forged crankshaft). Heads are built by MHS out of Florida and have a stage 3 port and polish ans 5 angle radius valve job. The Camshafts were also built by MHS and are stage 3 NA cams. Currently it produces 290 RWHP at 6000 rpm and is coupled with a 4R70W transmission with a FTI converter specd to match the engine. Also the heads and intake are both PI not the original NPI that came with the car. With all that said my goal from here is to make an engine that will produce 500-600 RWHP. My question is what advice would be have as the best way to do that. I know that a forced induction build is the only logical way but what would it take to make my 4.6 2v reach those numbers. I appreciate any advice people on here can offer and appreciate all the help. Thank you.

 

[Sluggie24]

The big question is how is the bottom end set up? What are the bearing clearances, ring gaps and compression? These will decide what level of boost you can put into it and have the engine last. The amount of boost will decide your basic power level.

Assuming it was set to the same specs as a stock N/A engine it should take 10psi intercooled which I would think would put you in the 400-500 rwhp range depending on the cams and tune.(i would suggest replacing the cams with blower specific cams for max power)

 

[mogs01gt]

The n/a cams will hurt you a tad once you slap on forced induction. What are the goals with the car, drag racing, road race, autoX or do you just want 500hp? Your numbers are a tad low for N/A With that big of a cam, I'd assume you would be around 310-315rwhp.

I bet its a low compression piston

 

[Eric22ff]

The big question is how is the bottom end set up? What are the bearing clearances, ring gaps and compression? These will decide what level of boost you can put into it and have the engine last. The amount of boost will decide your basic power level.

Assuming it was set to the same specs as a stock N/A engine it should take 10psi intercooled which I would think would put you in the 400-500 rwhp range depending on the cams and tune.(i would suggest replacing the cams with blower specific cams for max power)

So for clearances the rings are as follows Top: .005nd Middle: .015. Im not sure what the clearances are on the crank and main bearings all i know is i didint deviate from stock when doing the install. As far as compression goes i believe its running a 10.3:1 or 10.5:1. and I also agree on the cams, I already know that I would be switching out the cams for blower cams. the overall budget im trying to stay under is 10k. but im also using that number with rear end work in mind.

 

[Eric22ff]

The n/a cams will hurt you a tad once you slap on forced induction. What are the goals with the car, drag racing, road race, autoX or do you just want 500hp? Your numbers are a tad low for N/A With that big of a cam, I'd assume you would be around 310-315rwhp.

I bet its a low compression piston

The Goals for the car are drag racing ultimatly and just a fun drag/ street car. I would have liked to get into autocross but the auto trans will likely hurt that. I agree about the cams and i would switch them out upon adding a supercharger, if that would be the best route. As far as not hitting 310 RWHP the reason may be the auto trans as well as the person I had tune my car doesn't tune for max HP but rather for the flattest most efficient HP curve. Also forgot to mention the budget im trying to work with is 10K which is including potential shop labor or rear end work. Im hoping to do most everything on my own but may need a shops assistance with certain things. As far as compression its (i believe) 10.3:1 or 10.5:1

 

[Sluggie24]

I'm not an expert but the top ring end gap seems too tight for a supercharger. The compression would work as long as you don't go high boost and have a good tuner.

 

[Neuron]

I hope your trans isn't stock, 500-600+ HP at the flywheel is a lot on a stock auto.

 

[mogs01gt]

The Goals for the car are drag racing ultimatly and just a fun drag/ street car. I would have liked to get into autocross but the auto trans will likely hurt that. I agree about the cams and i would switch them out upon adding a supercharger, if that would be the best route. As far as not hitting 310 RWHP the reason may be the auto trans as well as the person I had tune my car doesn't tune for max HP but rather for the flattest most efficient HP curve. Also forgot to mention the budget im trying to work with is 10K which is including potential shop labor or rear end work. Im hoping to do most everything on my own but may need a shops assistance with certain things. As far as compression its (i believe) 10.3:1 or 10.5:1

IMO, with that kind of compression, your tuner better be pretty good or he'll need to pull a lot of timing to get it to not detonate.. I'd shoot for a lower HP amount and worry more about the tranny and rearend. If its going to see drag strips, you'll pop either on sticky tires. These cars can lunch pretty well and getting into the 1.5 or 1.6 sixty foot range breaks parts in the 600hp range.

 

[billfisher]

Well. The ring gap is risky tight. But a 200 shot is the ticket. Tune it really fat. Run 110 octane or higher on the spray. Imo