plaf713

iTrader: (8)

thank you, its not just our displacement that makes out engines superior to the n/a 4.6, it is just a damn better engine. Numbers don't lie.

Bitemark46

No, its cubes. You can throw 4 valves per cylinder and have 4 cams. But having only a 3.5" bore you're still not gonna move as much air as if you had a 4" bore with a stroke that is less than the bore. A square motor (3.55x3.54) is not the best in terms of making hp. You want a bigger bore and a shorter stroke. The LSX platform makes more power is because of cubes and a better borexstroke combo. Ask yourself this.... If a modular motor had the same bore and stroke as an LSX motor do you think it would still make less hp?

Highest N/A 4.6 (stock displacement) mod motor makes about 400-420rwhp.
Highest N/A 5.4 (horrible rod ratio) mod motor makes over 600rwhp.

Cubes win in period.

-Mark

BigBronco

iTrader: (2)

Hi. My name is reading comprehension and you have apparently missed all of my posts in this thread.

plaf713

iTrader: (8)

some people get so tense, you have a more complax motor, the physical size of your engine is that of a big block and you make shitty power, bigger displacement or not. The ls1 is an all around better designed engine that makes tremendous power, unlike the modular 4.6. I bet if there was a 281 ls1 it would still make better power than the modular 4.6

Bitemark46

Not getting uptight. But its obvious you don't know the science about building motors. You just say X motor is better than Y. But you state no facts. Read up about engine building then you'll understand what we are talking about. -Mark

plaf713

iTrader: (8)

oh i understand, i actually have a first hand experience, i had a cam only lt1, made 340 rwhp, decide to stroke it, kept the same heads because i did not have money to port yet, went from shorty headers to longtube, then dynoed the car witha 383 engine, dynoed 352 rwhp.

F8LWS6

iTrader: (11)

Does no one make decent heads at all for the motor? What does the best set of heads flow?

plaf713

iTrader: (8)

patriot has a set of heads that flow 316 cfm for the cobra, the best ive heard of

F8LWS6

iTrader: (11)

Yeah I just looked at them. The 2v heads don't really flow good at all (Compared with an LSx head). The 4v heads aren't that bad.

blck89rs

thats not first hand experience imo , first hand experience is actually building various types of engines, ive done SBC/BBC since i was about 13, 2 SBF's and now im building a 4v mod motor, and ive helped on an ls1 and done an lt1, im not bragging but im saying thats what motor building experience is, having a broad knowledge of many engines , not just building one and automatically thinking you know every engine is the same to build , these mod motors are nothing like an lt1 or ls1, because as stated before poor boreXstroke doesn't make power, lets prove this, a 302 SBF can be made into a really quick motor on stock cubes because of the 4" bore and 3" stroke is a good match ,


moral of the story , mod motors do not suck, they just need High rpms for N/A applications to make the power because of poor design

Bitemark46

Here are some stock flow#'s for modular heads. -Mark

http://www.mach1registry.org/photopo...cat=500&sort=1

F8LWS6

iTrader: (11)

Thanks for the link. Those honestly are some really poor numbers. Yours is awesome though man.

Cubes don't make any difference if your top end is garbage. Take my fathers 1978 Lincoln. Yeah it has a 460 but its lucky it makes I think 210 horsepower. Everything from the heads up are killing the thing.

BigBronco

iTrader: (2)

I am glad that you are out wrenching, but that is not what I would call 1st hand experience or any form of R&D.

Just to let you know, when I was planning on running a modular motor in my fastback (Prior to moving to the LS1), this was the sheetmetal intake I was going to run on the 4V setup....












This motor was going to be boosted though.

Adam_346

^^ thats nice

Apex_632

did you build that yourself? so when you gonna give me some pointers on a nice h/c combo for when i do my lsX swap?

BigBronco

iTrader: (2)

I had picked it up from a guy who had John Beck build the manifold. It was originally supposed to go on an 03 cobra in Houston.


As for the pointers, you know how to get a hold of me. Just let me know!

Apex_632

it'll be a slow process but for a project like this i much prefer having things planned in advanced so i'm not choosing as i go. i'd rather know exactly what i'm saving and paying for. i will definately get in touch with you soon.

1fastz

iTrader: (16)

Very True!! Mach 1's are N/A and hang with ls1's and thats pretty impressive.

quiet_storm98

iTrader: (48)

there are stock cubed na ls1's in the 9's..futral motorsports built one and there is also another one on this list
https://ls1tech.com/forums/drag-racing-results/749327-all-time-fastest-na-ls-any-c-i.html

bigwoode

iTrader: (2)

i wouldnt say that.. compression means alot, i had a 77 trans am with a 400 ci block, thing didnt move for ****. more ci doesnt mean more power