331 with AFR 205's

[FiveOCapri79]

I'm in the process of building a serious street/strip motor for my car. I'll be using the AFR 205 heads, with Scat forged internals in either an A4 or Dart block. I'll also be using dished pistons for the PT-88 turbo that will follow soon after it's built. The question is, what size injectors should I use while before the motor becomes turbocharged? I was thinking 30# would be enough naturally aspirated. What do you think?

 

[aleborjas]

30's for N/A and 42's or more for power adder!

 

[Grn92LX]

30's will be ok for now but why not just do it all now the RIGHT way instead of buying/swapping twice? You're gonna be doing a full fuel system I assume. Stock stuff ain't happening with that combo.

You're gonna need a big injector for this.

 

[304billet]

Why use a A4 block? Either use the SVO R block or the Dart. The R is good to 1500hp and the Dart IE is good to 2000hp.The A4 is good to 1200. Use a Scat 4340 profiled crank, u have to ask for this one, the profiled one costs the same as the other 4340 that is not profiled. Scat 4340 H -beam rods w/ the ARP 2000 rod bolt upgrade and Ross, CP or JE pistons, 9:1 comp. Have the rotating assembly internally balanced.

There was a R331ci stroker in one of the mags a couple years back that used a turbo on a 331 stroker w/ the AFR 225's that engine dynoed over 1000/1000.

30lbers will be fine. My friend's NA 347 stroker uses 30's.

 

[Rick 91GT]

The A4 is a good block, really not much different then the R302.

If I had my choice I would go DART block, it will cost less in the long run. I agree with Mike however if you run the motor with out boost a 30-36# should be good, and if you are going to a aftermarket EFI system go with a 72# low impedence with the 88, if not I would atleast a 55# high impedence inj with the boosted combo.

 

[lwtchlx]

Look at it this way a 88mm turbos max horsepower is generally around 1200-1300. The Acceleronics VersaFueler Injector Driver that splices into your factory ECU and lets you run low independence injectors. I found that on the Holcomb motorsports website the other day. You might wanna get some better flowing heads maybe step up to the 225 AFR b/c w/ that large of a turbo your gonna move alot of air. And you might wanna look into gettin the scat lighter weight cranks (i believe they have a superlight knife edge piece but its kinda pricey) so your motor can turn up higher b/c its gonna take a lil bit to spool up that hoss of a turbo. Sounds like your gonna have one bad ride when all is said and done.

 

[FiveOCapri79]

In regards about doing it right the first for the injectors, cost is a factor. I can only afford to build the motor for right now. I figured the A4 or the cheaper Dart block(around $1800) would be good enough since my goal is about 800rwhp. The crank I was talking about was a lightweight, profiled Scat. I'm also debating if compression should be 8.5:1 or a little higher to 9:1 since I'm trying to keep this setup running on pump gas. But like I said, my goal is to have a street AND strip car. The hardest part is making sure I'll build boost using a Tremec TKO 600.

 

[TT91]

Good luck finding a decent A4 block these days. Better off with a Dart sportman block. Go with some sort of aftermarket fuel injection and large injectors to start. Your goals and combo sound similar to mine, check out the link in my sig, let me know if you have any questions.

 

[bob331T76]

lol A4 block no dont make that mistake, go with dart , i have the same set up dart 331 afr 205 hollysystem max 2 24#s and runs great 380rwhp and 360rwtq , all forged internals, puttn in the T76 as well speak and im useing 72#s, this will handle at least 1000rwhp

 

[FiveOCapri79]

Just curious, but what's so bad about the A4 block? I've seen numerous setups using them with good results. Nice car by the way TT91

 

[Rick 91GT]

Really nothing is wrong with a A4 block, but they are hard to find since they were replaced with the R302 a few years back. The new technology blocks like the DART Iron Eagle, Sportsman and World Products Man-O-War can be bored further, handle large strokes and take more power however.

 

[FiveOCapri79]

Isn't the R302 a siamese bore? If so, what sort of problems would I run into using that instead of something else?

 

[bluevenom867]

Isn't the R302 a siamese bore? If so, what sort of problems would I run into using that instead of something else?

siamese bore > non-siamese bore

They dont run any hotter and they wont shift/deform like a non-siamese bore can.

 

[FiveOCapri79]

Other than cooling issues, do the heads have to have any special work done to the water passages or etc.? Forgive my newbie questions, but I'm not too familiar with siamese blocks. Also, where's a good place to order a Dart Sportsman or R302? The best price I've found on the Dart was $1800. I've also found a fully machined A4 with a girdle new for $1700 but I haven't found any R302's.

 

[bluevenom867]

Other than cooling issues, do the heads have to have any special work done to the water passages or etc.?

No...

They go on thous blocks just like a factory block.

 

[FiveOCapri79]

I guess the last thing question to ask is which would everyone prefer? R302 or Dart Sportsman?

 

[FiveOCapri79]

Any opinions on my last question? R302 or Dart Sportsman?

 

[Rick 91GT]

Coming from a builder.........

DART

 

[5.0 HOtrain]

I agree with Rick, Dart. Not only that, when you buy a fully machined block, it was machined for someone elses pistons. Buying you're block new, as long as you have a good machinist, every piston is measured and every bore is matched to it.


:OT: Rick, have you used a new World Products block yet?

 

[Rick 91GT]

:OT: Rick, have you used a new World Products block yet?

Yeah, heavy ******..lol 225lbs 8.2" deck 302, other then that I liked it, 1/2" mains studs, doweled main caps, requires custom head studs $174 since the threads are recessed .500" into the block, a couple special plugs are required here and there. I'd recommend one to someone who isn't worried about some extra weight up front. Side by Side it makes the DART looks small.... I'll post some pic's let me see what I can find.