|
351 sportsman block
A question for your experts out there concerning the 351 sportsman block. What are the differences between the original windsor block and the sportman block? Are there any physical or structural differences that can be detected from the outside of the block? Thanks in advance for the help.
|
Call the Ford tech line, (do a search or look in a FRPP catolog for the #) they can tell you the visual differences. Sportsman block is good for 700 or 750 HP. Not sure how to tell it apart from a stock one.
|
Mike,
I think they offer two versions of the sportsman block...one has a 9.2" deck height and the other is a 9.5"...Some of them also have smaller main journals and are dry sump. If you're just talking about a plain jane 351w sportsman like they have in the Jegs catalog, I don't really see any differences. Just beefier. |
Ford racing now has what they call their generation two sportsman block. It is the best sportsman block yet. Much thicker main webs, pan rails, thicker deck. We have people making up to 900HP with the new block. It does have extra water holes in the deck for the N-351 heads and the Yates heads but these need to be blocked of with all other heads. It is only available in a 9.500 style with 2 bolt mains and the standard 3.000 main size like the production block. Makes a great block for a 408 to 427C.I. small block build up. You will see that the new block has more freeze plugs with freeze plugs on the front like the other Ford racing blocks. The new blocks sell for 1195.00 and are on back order till October 30th, this is what ford racing tells us because we keep them on order all of the time. Thanks, Keith Craft
|
Blocks
Reading about the sportsman blocks capable of handling between 700-900hp. As I am only expecting to make about 500hp from something like a 393 engine, is there any need to go to one of these blocks, and also should you fit four bolt mains, or a girdle if you want to rev to around 7000?
Money will dictate the outcome, I have looked at Dart Iron Eagle and the alloy block, RDI Alloy blocks, apparently all the weight saving is about 60Ibs on the RDI 427 over the cast block. The bottom line is if I where to find a block around 68-71 vintage and fit a girdle line bore etc from what a lot of you have said it should never give a problem? I am a perfectionist with out the resources, but have patience, and can't wait to get out on the track! |
Keith - the 900hp guys, are they having the block converted to accept staggered 4 bolt main caps, or leaving them as 2 bolt?
If converting, how does the end price compare to an existing 4 bolt FRPP block? |
What about stock 351w early and later blocks hp level?
|
A 69 block will have no problem with 500 to 575hp, you can even run this hp with out a main girdle. These blocks are pretty strong, and with a main girdle will have no problem in the 700hp range. I'm currently building a 700-800hp 351 stroker motor, which uses a 69 block. One thing to check is how your block was casted. This can be done by drilling into the casting and checking the thickness at point locations, also looking at where the cam journals were machined will show if it was properly casted. The castings do have differences, but for the most part at only 500hp you will be 100% fine with no problems. If you cant find a 69 block, my next choice would be a 70-71-72. I wouldnt go with 73+. Although the casting stayed the same for 73 and 74 the nickel content actualy dropped making them not as strong. If you have trouble finding a 69 block, I have a few of them in my garage I can sell you.
Ben |
We have guys running b lowers and turbos on the new style Sportsman block with the 2 bolt caps and making 900 HP. These guys have there engines tuned well and have not detinated the engine. Ford called the other day and said the current Sportsman block has been given a new part number and a few changes have been made for the better. I will have to waite and see. we had to cancel the Sportsman blocks we did have on order and order more under the new number.
We have plenty of guys running the Windsor blocks up to 600HP. I would watch turning it 7000 very often without internaly balancing. We will hold the 408 engines to about 6700RPM with the factory 28 oz balance set up. We have been using these blocks for a long time and have had real good luck with them. Thanks Keith |
Quote:
|
We will normally use the early blocks like 69 thru 74 castings. I have had some blocks that were made in the late 80's and they looked pretty good as well. A lot of this durability deals has to do with the stroke weight of the rotating assembly as well as RPM. I feel all of the blocks are good for 550 to 575 HP. Where we have seen some of the problems is with the stroker stuff the guys are turning 7000 to 7500 with the external balancing. This whips the crank and will knock out the number 2 and 4 main. I have seen it crack the blocks in the main bolts holes as well as crack the block in the main webbing. I feel that if the engines were zero balanced or externally balanced this would not be as a big of problem.
Eagle had just released their 4.00 4340 steel crank in a zero balance form where it does not take 6 to 8 pieces of mallory metal to balance. Now we can run these engines zero balanced like the Chevys came from the factory. This makes everything much nicer, just get a zero balancer damper and flywheel. Good luck, Keith Craft |
| All times are GMT -7. The time now is 11:57 AM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: