need suggestions for a 331 stroker build

[njmaier]

I have a Keith Craft 331 stroker short block that I am going to have freshened up. I'm looking for suggestions on what to go with for a top end setup.

This is purely a street car. It might make a pass or two at the drag strip, but that's going to be a rare occurrence. It's not a daily driver, but I do want to own the street when I'm out in it . It must use pump gas, and 91 octane is as good as I can get around here.

The bottom end is fully forged. The current pistons in it are JE 9:1...not sure what the dish is. I think I may be able to reuse them, but if I need to use something else then that's what I'll do.

I don't plan on boosting it down the road. I think I want all motor. That being said...how high of a compression ratio can I run and still be able to run a small amount of boost later?

Give me some ideas for heads, cam, and intake please. Budget isn't a concern...if I can't afford it all I'll save money until I can.

Thanks in advance!

 

[tannerc91gt]

You're trying to go too many ways at once here.

If you're trying to get all you can out of it on pump gas N/A I'd up the compression. Obviously your pistons aren't the sole factor in compression so your head choice and HG will be a concern. For an NA build (EFI I'm assuming) I'd go
AFR 185s
Trick flow R (not box)
Custom cam


You'll be able to do plenty with that combo and if you ever DO decide to boost it (assuming you keep the
Pistons you have) you won't be in bad shape.

If you could find out the CC of the dish and the deck height, I'd be more than happy to figure up an estimated comp ratio for the different heads. There's a lot more to consider though

 

[njmaier]

Yeah...sorry about that. My mind tends to have a million things running through it at once.

Let's just think about all motor then.

The pistons are JE p/n 168764. I haven't been able to find more info on them...I haven't called JE yet though.

I'm not looking for the definitive setup here. I'm just looking for some suggestions so I can have an idea of what I'm looking for when I go to the machine shop. Just wanting some unbiased info...don't want to buy the wrong parts for the shop to assemble.

Thanks.

 

[tannerc91gt]

Nothing comes up for that part number but if the shortblock is older than it probably has been replaced by a new PN.

Basically, if you're sticking NA and to the street, I'd personally want something with a power band that will be fun out in town. No sense to me building something that spins to 7500 if you're just going stop light to stop light

 

[tannerc91gt]

Can't edit my posts in mobile, but considering you're just looking for a Reasonable street combo, what i suggested may not be the best bet. Also, I'm assuming it's a factory block?

 

[njmaier]

Yes...it is production block that was prepped, machined, and clearanced by Keith Craft back in 2001. I have the original build sheet for it from back then.

 

[Gearbanger 101]

The Trick Flow Track Heat Top end kit would be about cat's ass on a 331ci street engine. Keep the compression in the 9:0-9:5 to 1 range and you'll make 350-370fwhp all day long. High flow heads are great for making power, but staying conservative with your selection will insure a nice, broad torque curve at all RPM. The 170cfm castings with the Trick Flow kit will provide plenty of flow and velicity for your needs. With a 6-8psi centrifugal later on down the road, you'll knock out a very pump gas friendly 425-450hp and still retain excellent street manners.

This will probably be the direction I take me coupe in the next year or so.

You also mentioned in an earlier post running it with 24lb/hr fuel injectors and 73mm MAF meter. Those are going to be running on the ragged edge in N/A format with any healthy top end on that engine....never mind with a little added boost. I'd upgrade to at least a set of 30lb/hr squirters N/A and 42lb/hr injectors with forced induction. You're going to want to step up the MAF meter and throttle body size too.

No sense building an engine to make a boat load of power, just to choke it off at the inlet.

 

[njmaier]

The Trick Flow Track Heat Top end kit would be about cat's ass on a 331ci street engine. Keep the compression in the 9:0-9:5 to 1 range and you'll make 350-370fwhp all day long. High flow heads are great for making power, but staying conservative with your selection will insure a nice, broad torque curve at all RPM. The 170cfm castings with the Trick Flow kit will provide plenty of flow and velicity for your needs. With a 6-8psi centrifugal later on down the road, you'll knock out a very pump gas friendly 425-450hp and still retain excellent street manners.

This will probably be the direction I take me coupe in the next year or so.

You also mentioned in an earlier post running it with 24lb/hr fuel injectors and 73mm MAF meter. Those are going to be running on the ragged edge in N/A format with any healthy top end on that engine....never mind with a little added boost. I'd upgrade to at least a set of 30lb/hr squirters N/A and 42lb/hr injectors with forced induction. You're going to want to step up the MAF meter and throttle body size too.

No sense building an engine to make a boat load of power, just to choke it off at the inlet.

Is a 70mm TB sufficient generally? Or do I need to go bigger than that?

 

[Gearbanger 101]

Is a 70mm TB sufficient generally? Or do I need to go bigger than that?

As far as throttle bodies go....this is actually one area where bigger is almost always better. The Trick Flow intakes are designed to accommodate up to a 75mm unit.

That being said, you're not going to leave a whole lot on the table with the 70mm unit. Swapping it out for a larger 75mm unit won't be worth more than a few single digit horsepower and even then likely only at the top end of the tach. If you were starting from scratch, I'd say opt for a 75mm throttle body, but at this point IMO, it's not worth changing out.....stick with it.