I have worked vt heads with race components... What now?

[mdebono]

I have recently got hold of freshly worked VT 304 heads. They have had a mild port job, valve seats made bigger along with components all brand new. Isky dual race springs, chrome moly pushrods, caps and retainers, valves and a pretty wild cam. My plans are to build a pretty solid and very powerfull engine. Heads are rated to flow 520hp.

First thoughts are to buy a COME 355 stroker kit
Get block tapped so i can install 4 bolt mains
balance engine
performance intake
headers
twin drain exhaust
Deck block
Mill heads
twin throttle body
LS1 injectors?
11.1 compression
bore block ( unsure of oversize, want to freshen block without weakening it)

Give me all of your ideas! is anything im doing stupid or a waste of time?

For now i want to stay naturally aspirated but have minimum of 450bhp if not closer to 500. It may seem a bit extreme but even unstroked at 5L it is common knowlege that naturally aspirated the engine can exceed 600bhp ( obviously revving its tits off ).

Cheers guys!

[ryno_vrx]

the holden 5lt can make 450+bhp??? fark thats news to me

[mdebono]

Hows that suprising lol if a 2L 4cylander evo can make excess of 600hp then surely a 5L v8 can make 450. Like the evo the power is when and where and sacrafices of low down power are made. 450 isnt pushing it for a 304, maybe in street spec. v8 supercars for example, holden used the 304 and got them revvibg well over 7000rpm and got over 600hp and thats not stroked and still naturally aspirated.

[ryno_vrx]

yeah i know engines like the 2jz and the rb series can make insane amounts of power... but they do it with forced induction and they are well engineered and designed and a hell of a lot more sophisticated then the old 5lt

[mojododo]

lmao.... seen v8 supercars at all?

5000cc limited, theyre makin over 680hp n/a

[ryno_vrx]

yeah but they have huge budgets and dont have to worry about driving on the street and laws /regulations etc
unless this is going to be just a track/drag car but even then i hope you/your parents are rich

[greenfoam]

355 with decent heads with a solid cam, harrop single plane manifold. Will and does make just under or just over 500 hp everytime

This VN SS made 505HP with that combo, it idles nice doesn't make much sound, pretty awesome really

[ryno_vrx]

ah i stuffed up twice. i failed to notice he's going stroked and he wants 450+bhp my bad i had it in my head that he wanted rwhp, sorry op.
oh greenfoam if you get a chance can you please give me some advice on a cam, i wrote some details in your 304 cam choice thread,

[mdebono]

[QUOTE=greenfoam;1452212]355 with decent heads with a solid cam, harrop single plane manifold. Will and does make just under or just over 500 hp everytime

This VN SS made 505HP with that combo, it idles nice doesn't make much sound, pretty awesome really

Are my heads decent enough? ported, all rounded corners pointed, dual race springs and all that written up top flowing max of 520hp? Valves are the same size as a stock ls1 i think. My cams quite good. These manifolds confuse the hell out of me though, the one you reccomend is just over $1000 but one on 'At racing world' is $295? whats the major difference? sorry im a kiwi not to sure on these aussie brands its just beyond me why the prices vary so much. I,ve got the heads ( if theyr good enough ), the cam so i need the intake and stroker?

Basically im getting info and ideas as im tossing up whether to build the 304 or buy an 400hp ls1 and 6 speed manual gearbox for $4250 off a mate. Could i get the 500hp from my 304 for that price presuming my heads and accesories are adequite? And thats without labour.

Would like also an approx quote on a memcal to run engine if modded, you can e-mail me on pdebono@xnet.co.nz if you do not wish to quote on the forum.

Thanks for your help!

[greenfoam]

The AT racing manifold isn't any good, migth be ok for stuffing around no a budget 304 but if you want 500 hp your going to have to get a real one. The heads sound like they will do the job. The LS1 and getting it in the car will probably end up the same price or cheaper than building a stroker. For the tune I don't often do any tunes for strokers in the 500 hp range and when I do it's only to run the car in before they get tuned more on a dyno/road etc. If you are going to spend that kind of money you really want to spend alot of time on the tuning or do it yourself

[_R_J_K_]

These manifolds confuse the hell out of me though, the one you reccomend is just over $1000 but one on 'At racing world' is $295? whats the major difference?

Maybe because the manifold at AT Racing World isn't made by Harrop? I'm pretty sure most of the gear on that site is Procomp.

If you're doubting the quality of Harrop, Holden used their stroker cranks in the 215i motors. I had a look at the stroker cranks on AT Racing World, priced at $325, and the cranks at Harrop, over $1300. The stuff on AT Racing World is cheap for a reason.

[mdebono]

The AT racing manifold isn't any good, migth be ok for stuffing around no a budget 304 but if you want 500 hp your going to have to get a real one. The heads sound like they will do the job. The LS1 and getting it in the car will probably end up the same price or cheaper than building a stroker. For the tune I don't often do any tunes for strokers in the 500 hp range and when I do it's only to run the car in before they get tuned more on a dyno/road etc. If you are going to spend that kind of money you really want to spend alot of time on the tuning or do it yourself

Cool i understand that, ill probably end up selling my 304 parts and spend the equivalent on modifying the ls1, the deals too cheap to miss out on. Thanks for the help!