goal for my 98gt (engine wise)

[40oz]

The guy is building an engine from scratch here. If he wants the extra cubes from a 5.4L (which is ALSO an OHC engine), let him do so. There are plenty of aftermarket cams, heads, and upper plenums to get rid of this "4000rpm" plateau you speak of. Telling a guy not to buy a 5.4 because its a truck engine is not good advice.

There is a reason the only high-rpm performance 5.4 in the US was made 9 years ago for a track car. It's a poor design for that kind of use, given the long stroke to small bore dimensions. The 4.6 is a better design for a performance engine.

One might be able to use Australian Falcon 5.4 parts, but those are probably tough to come by an ocean away.

 

[Mr. Rustypwnz]

well I've decided on my goal. a mark bottom end with ported Npi heads. and an edelbrock intake. cams im not sure yet. but does anyone know the comp ratio that would be if I used the stock mark pistons with npi heads? im goin to do a lot of work to these heads the port on the intake will be matched to a pi port so the intake will flow better. the bottom end will get prolly some rods and pistons. I would like to spin it to 7500ish. thus thr edelbrock intake. im not a fan of low reving small cube motors.

 

[blackfang]

Yes, A Teksid block is much stronger. Personally I would get a built forged bottom end with a good h/c setup with some juice or a blower. Then again, a 5.4 DOHC would be nice too Then again, Mr Papito aka Boss330 (one of the best and well known Modular engine builders/racers) runs 9's with his NA 5.4

 

[Mr. Rustypwnz]

im going to build something that I can order all the parts for. and not have to modify excessive **** for it to work. the only thing I want to modify is the heads. I've ported and worked many sets of heads with good success. so that dosent worry me, and its cheap. just want a high revving 4.6 that's not a 4v and that makes decent power.

 

[ninjastang125]

Yes, A Teksid block is much stronger. Personally I would get a built forged bottom end with a good h/c setup with some juice or a blower. Then again, a 5.4 DOHC would be nice too Then again, Mr Papito aka Boss330 (one of the best and well known Modular engine builders/racers) runs 9's with his NA 5.4

high comp. ratio + boost = kaaaboooom

 

[Mr. Rustypwnz]

well I found that with a stock mark bottom end it will be 11.3-1 with npi heads with pi's its 12.5-1 looks like im goin with npi's.

 

[CobraRed_96_GT]

Might have to splash some race gas at it to make the most power. And even with ported NPI's that's like having to run race gas to make 325rwhp - that kinda sucks.

 

[blackfang]

high comp. ratio + boost = kaaaboooom

Who said anything about a high compression ratio+ boost? You do know you can get a built motor w/ forged internals that is setup for nitrous or a blower.

 

[98COBRA281]

well I found that with a stock mark bottom end it will be 11.3-1 with npi heads with pi's its 12.5-1 looks like im goin with npi's.

i run mark 8 piston, 2.66cc dish, it makes the compression ratio about 10.2:1 with NPI heads, not 11.3:1.........

and running race gas at $7+ a gallon to make 325rwhp would suck................

 

[Mr. Rustypwnz]

well **** man I was way off on that. I guess ill run pi's than. I've had a 11-1.1 5.0 and I ran 16 deg in it with 93 so ill be fine. although soon my car will be a full pi swapped car. just need some heads. im in stock ls1 territory right now. all I want to do is hang with a cammed ls1 (big task!!) lol. I think with a 100 shot I can be close to that after my heads.

 

[ninjastang125]

Yes, A Teksid block is much stronger. Personally I would get a built forged bottom end with a good h/c setup with some juice or a blower. Then again, a 5.4 DOHC would be nice too Then again, Mr Papito aka Boss330 (one of the best and well known Modular engine builders/racers) runs 9's with his NA 5.4

you said something about high comp. and blower. nitrous would be fine but boost

 

[blackfang]

you said something about high comp. and blower. nitrous would be fine but boost

I never said anything of the sort. Nothing in that quote talks about a motor with high compression and blower. Looks like you are reading into it