I'd like some opinions on this. A VT Stroker shortblock with billet rods is 4695. A VT Big Bore shortblock with billet rods is 4495. 200 bucks is peanuts in a build like this. What do you guys think will be a better choice for a turbo mod motor, I'd like to achieve 1000 RWHP or more and keep it streetable, probably running a pair of GT35R's. The stroke sounds nice for torque, but the big bore would give even more head flow. Whats your opinion?

 

I would always go with a big bore over a stroker on a 4V. Extra displacement is good, but unshrouding the valves with the 3.7" bore is a huge bonus. With 3.7" bore you can move up to 39mm intake valves witout worrying about getting into the firing ring.

I have some KILLER heads for a 4V if you are looking. 325intake, 265 exhaust @ .500

 

Hey im interested in those heads, do they come with cams? what year are they?

Ive got a 01 FORGED cobra motor in my 02 gt with twin 57s. Theyre getting installed and tuned with full suspension and fuel system, etc. next week finally!

 

BTW-I wouldnt do a stroker or big bore. Just run a little more psi and In my opinion it would be safer...

 

I don't see how it would be any safer, and did you ever see that article MM&FF ran? A 3.75" crank in a 4.6 motor was worth like 30 ft-lbs in the mid range, that's the kind of thing that I feel is definitely worth it for a street car.

After a bit more thinking, I may just end up going 324" if I can find a stroker crank for a good deal.

 

I have seen many stroker cranks fail in 4V applications while these same cranks survive in 2V engines all day long...

I believe this is due to a couple of things.

1. Weaker aluminum block with snort skirts
2. Much higher RPM

Witnessing what i have over hte past couple years I would never rev a stoker 4.6 past 7000rpm's.

I would also never own a 4V that I could not rev past 7500. That is why big bore is my choice. Let those four valves breath a little more...

 

305" it is

This is what Pappitto recommended too, so I think i'll go with the big bore.

 

Listen to AL. He is no dummy..

 

well imo they walls are just to thin on a big bore, and like the other said about the cranks failing. I just dont think its worth the money or extra risk, but i just wanted to build mine 1 time and thats it.

 

the 3.7" sleeves are just as thick as the stockers. You can always go darton and have something much stronger

 

I've got the 3.75 stroker in a teksid aluminum cobra block. Although I am running 2v heads for the moment I plan to switch over to 4v sooner or later. I have had no problems.

 

VT doesn't recomend over 20 psi of boost on a standard big bore (dry sleeve) modular engine. You would definetly want to go with the Darton sleeves (wet sleeve design)! For 1000 rwhp 4v modular I would imagine you will be pushing over 20 psi......do the Darton sleeves and be confident that you won't blow out a cylinder wall!

You'll be looking at around $7000+ if you do a Darton sleeved big bore stroker (324") shortblock from VT.

Ken

 

Yeah, I read more into the dry and wet sleeves.

You gotta pay to play though, right?

 

Interesting...I build this all day long....and I've NEVER seen a stroker crank fail. The 2 most powerfull 2V motors both use stroker cranks ...... my 324 4V made 1448hp with 22psi, Lamotta's stroked 4V makes over 1000rwhp.....

What exactly did you see fail? Just curious.