strength of a stock 351w?

[95turbo351]

I was just wondering if anyone had an idea about how much hp and torque a stock 351w block out of a 1990 bronco could handle. I was going to put it in my 95 gt and then slap on a Holset h1e turbo on it.

 

[nmcgrawj]

The old blocks hold more. But the later ones are still strong although i have heard from one or two that they really arent. Do a search on year and corral to find out. Im pretty sure people have had them hold to 6-700. But sometimes people go further and other times people come a little short.

Gotta pay to play. I have been thinking about a turbo...GOOD LUCK!

 

[95turbo351]

Yeah I've heard that it would handle up to about 600 or so too. I got the block pretty cheap at a junk yard so I wouldn't be too dissapointed if I had to invest in another. It's just that my friend who's helping me build this said that if tuned and balanced it right, put 4-bolt splayed caps on, and a valley girdle pro on it that I could run around town normally with about 400 or so hp and be able to safely boost it up to about 775-840hp from time to time with no problems. I tslked to a frrp tech rep and he said that it would only hold 450hp, and that I would have to switch to a siamese bore block to handle what I want. I think he was probably just trying to sell me a new block. Also I'm not sure what you ment by looking up the year and corral on it.

 

[bjl95mustang]

Ok, You really can only put the 4 bolt main caps on a older block like the 69. The 90's blocks are said not to be as strong as the older blocks due to less nickel content. And did you mean a gridle that goes on the caps or a gridle that goes in the lifter valley?

Are you wanting a stroker or are you using the stock rotating assy?

www.hardcore50.com Do a search on the message boards on this site. I have seen alot of talk about the 351 blocks.

 

[BlackVert]

the party line is that you shouldn't go much above 450 hp (at the crank) with a stock 302 block, but people have done it, just look at jr (94turbo5.0).

i have also heard that the older 351 blocks are stronger. there is alot more metal in them, especially if you don't bore them out. i imagine it is a similar story with the 351 blocks ... the "rated" power level is conservative and you can probably go 50hp above it without worrying too much.

good luck and welcome to the forum! oh, and one word of advice ... we like pictures here!

- chris

 

[mustangman33]

You guys are correct, the 351w can hold upto 500 pretty safely, you can girdle it and convert to 4bolt main, but you will not gain much more strentgh, the mains are still pretty small. If you want big power numbers just up the compression, full fill the block, then you can get in the big hp numbers like 640hp and you can throw on a 400 shot nos, but thats strictly for the track, I was planning on doing that but Im getting a Dart block in the spring. But safely the 351 can only handle about 450-500hp safely, and that can be pretty costly N/A. Even the older blocks cant handle lots of power, they may be 4bolt mains but that the bolts arent the same size.

 

[95turbo351]

I was going to use a stock rotating assembly with a forged crank, h-beam con. rods, and forged Ross pistons. The valley girdle pro is a lifter valley support, they advertised it on ESPN 2 and I think the name of the website that they sell it on is horsepowersales.net. They claim to have used this on a stock 302 and that it survived something like 9,500 rpm or so they claim . I'm trying to make a streetable 351 that can withstand up to around 25psi from my h1e turbo. Not sure if this block will hold it, it seems to still be in good shape, has original stock bores, no cracks or any wear that .030 won't take out. And I would have a picture of my car but my cam broke and am waiting o see if I could borrow one from a friend. I'll get pics as soon as I can. Its' a red 95 GT, 2003 cobra rims, lowered by eibach springs.

 

[zenboy99]

The question is not the strength of the block but the oiling with the large main's. The Dart block has Cleveland mains and doesn't have a problem.

Check the hardcore website for oiling tips with a stock windsor block.

 

[bjl95mustang]

The valley gridle wont do anything. It has been talked about on www.hardcore50.com by the owners of coast high performance and other big engine builders. The block tend to crack mor on the caps and not the valley.

I don't see a stock block holding with that much boost. You will find more info on 351's on www.hardcore50.com

 

[a50sn95]

I always thought that Lidio @ Alternative Auto knew his stuff.
He has some info for you/us...
http://www.alternativeauto.com/waterbox/wb_archives/347_vs_351.html
http://www.alternativeauto.com/waterbox/wb_archives/351W_strokers.html
http://www.alternativeauto.com/waterbox/wb_archives/351_nut_bolt.html
Dennis

 

[95turbo351]

After listening to you guys and going through some other websites forums I think I'm just going to go with a dart 351 block instead of chancing this one. I'll just let my stepdad use my junkyard block for his 69 mach 1 rebuild. Thanks for the info