Good block to stroke to 331 or 347?

Mustang_289 · 10-13-2003, 07:18 AM

My son picked up an old motor with about 90K on it from I believe a 90/91 stang. He wants to strip it down and use this to build a stroker.

His ambition is a pretty steller race motor with occasional street use.

Is this a good block to use, or are there specific blocks that are better then others? This block is a 2 bolt main, should we look for a 4 bolt main?

fiveohpatrol · 10-13-2003, 01:12 PM

It all depends on what the plans for the motor are.

A enormous amount of compression, alot of RPM's, or a lot of boost or nitrous wouldn't be a good idea with a stock block.

But if you plan on a mild power adder, or just running pretty strong NA, then a stock block will suit you just fine.

Just to be sure, you can add a main support system, which will greatly increase the strength of the lower end .

If you are set on finding a 4bolt main block, then it won't be cheap. The Dart, or A4/R302 blocks are your options, but you'll spend more money on just the BARE block than most complete stroker kits out there these days.

302 LX Eric · 10-13-2003, 02:52 PM

Excellent response above.

I'm using a DSS stroker package for my 331 along with their Main Support System to help tie together the bottom end.

The stock block is good for more than people give it credit for. You can get 400-450 HP out of it without a worry, IMHO. Plus, it's inexpensive, relatively light weight in comparison to the Dart or A4/R block.

E

stang_racer20 · 10-13-2003, 10:35 PM

the combo i am putting together is probably going to make around 700 rwhp. so i went with the b50 sportsman 302 block. bought through jegs for 900 dollars it comes as a newly cast iron block with strengthened walls and main cap areas.

jonnyk · 10-15-2003, 07:47 AM

Once you get beyond about 500 rwhp the stock block will split up the middle EVENTUALLY. The B50 block is stronger yes, but in the wrong areas IMO, it's the bulkhead in the lifter valley that is the weak point and they don't add much/if any meat in this region. Some guys have split the B50 already too. Because of this, I don't ever recommend a main support because they aren't helping the weak spot, and are only good to hold together the block once it splits. Your best bet is an R block or Dart block for serious power.
As far as RPM's are concerned, I haven't personally heard of a case where main cap walk was the reason for engine failure...I wouldn't be hesistant to spin an all motor 2 bolt 302 to the moon at all. A set of main studs is good extra reinforcement as well.

10-13-2003, 07:18 AM	#1
Mustang_289 Registered Member Join Date: Sep 2001 Posts: 512	Good block to stroke to 331 or 347? My son picked up an old motor with about 90K on it from I believe a 90/91 stang. He wants to strip it down and use this to build a stroker. His ambition is a pretty steller race motor with occasional street use. Is this a good block to use, or are there specific blocks that are better then others? This block is a 2 bolt main, should we look for a 4 bolt main?

10-13-2003, 01:12 PM	#2
fiveohpatrol I'd rather be basketweaving Join Date: Feb 2000 Location: Indianapolis Posts: 2,551	It all depends on what the plans for the motor are. A enormous amount of compression, alot of RPM's, or a lot of boost or nitrous wouldn't be a good idea with a stock block. But if you plan on a mild power adder, or just running pretty strong NA, then a stock block will suit you just fine. Just to be sure, you can add a main support system, which will greatly increase the strength of the lower end . If you are set on finding a 4bolt main block, then it won't be cheap. The Dart, or A4/R302 blocks are your options, but you'll spend more money on just the BARE block than most complete stroker kits out there these days. __________________ NMRA O/C 9516 NA pumpgas stickshift 347 10.65@125.6, 6.73@100, 1.41 60ft

10-13-2003, 02:52 PM	#3
302 LX Eric or '331 LX Eric' Join Date: Jan 1999 Location: Columbus, Ohio Posts: 2,142	Excellent response above. I'm using a DSS stroker package for my 331 along with their Main Support System to help tie together the bottom end. The stock block is good for more than people give it credit for. You can get 400-450 HP out of it without a worry, IMHO. Plus, it's inexpensive, relatively light weight in comparison to the Dart or A4/R block. E __________________ 1991 5.0 LX Coupe - 40,750 miles 331 cu. in. / Tremec 3550 / BFG Drag Radials 12.22 @ 114.31 mph - w/1.89 60'

10-15-2003, 07:47 AM	#5
jonnyk Being stroked is great Join Date: Oct 1998 Location: Alberta, Canada Posts: 772	Once you get beyond about 500 rwhp the stock block will split up the middle EVENTUALLY. The B50 block is stronger yes, but in the wrong areas IMO, it's the bulkhead in the lifter valley that is the weak point and they don't add much/if any meat in this region. Some guys have split the B50 already too. Because of this, I don't ever recommend a main support because they aren't helping the weak spot, and are only good to hold together the block once it splits. Your best bet is an R block or Dart block for serious power. As far as RPM's are concerned, I haven't personally heard of a case where main cap walk was the reason for engine failure...I wouldn't be hesistant to spin an all motor 2 bolt 302 to the moon at all. A set of main studs is good extra reinforcement as well. __________________ Novi 2000 now spinning off the snout of the 331... Mods Pics

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
302 Engine rebuild materials?	Tincan18	Windsor Power	5	04-25-2004 02:41 AM
Good Radiator	Patrick Boetticher	Windsor Power	15	02-27-2002 01:51 PM
85 5.0 block vs. 94 5.0 block (gas mileage)	jruppert	Windsor Power	1	11-12-2001 07:15 PM
Ready to replace bearings and install cam......What's a good spec??	Stang_ROTY	Windsor Power	16	10-23-2001 07:33 PM
Long block vs Short block?	mustang17	Windsor Power	4	03-21-2001 01:06 AM