davids94

I put my new 351 W on the engine stand at my brothers boat shop last weekend and immediately my excitement was turned to anxiety.

The guy who he works with has 18 years of boat repair experience and gave me some bothersome information.

The motor was bored by the machine shop to 60 over. He said that this may cause a significant overheating issue. Is this something to worry about? Up to this point no one has mentioned it but the guy makes a good point. The block will be significantly hotter with the extra cylinder volume. Is the engine going to be a risk?

In addition, the machine shop that I brought the block to picked up some heads for the motor. The exhaust ports on them are half the size of the ones that were on my Volvo Penta 302. Will this be an issue as well? Obviously it will constrict the flow and cost me a few horsepower but will I have another heat issue? Im no mechanic so I really need some advice here. Should I sell the motor Ive been waiting 5 months for and get something else? If its worth it to be safe and reliable Im willing to spend the extra cash.

Thanks in advance
~Dave

88Fountain

iTrader: (1)

Should be ok with the block, if it was a Cleveland block, it would be a different story. Had a 13:1 Cleveland motor in a race car that was .040 over, couldn't get the rings to seat correctly due to excessive cylinder wall flexing. This was due to the thin cylinder walls and it ran hot. As far as the heads, shouldn't be a problem there either.

davids94

Why would the clevland be a problem and the windsor not?

hillbilly24

There are 3 different 351 blocks. The windsor, the Clevland, and the M. They are completely diferent castings. Although what 88fountian said doesn't make much sense to me. The Clevland was a much stouter block. The Clevland was designed to be a 351. The windsor is the same block as the 289/302. And the 351M is a destroked 400.

davids94

So what do you think about my problem hilbilly? You seem very knowledgeable. I've really appreciated your responses to my other posts. THANKS!

hillbilly24

You may have problems with a 351W .060" over. Then again you may not. .030" is as much as I realy like to go on that block but .040" and .060" over pistons are widely available so some people must disagree with me. The problem you may run into is as 88Fountian said, clyinder wall flex wich won't allow the rings to seat properly and can cuase overheating when run in a mid to high RPM range for extended periods. I just think it is more of a 351W problem then a 351C issue. If you can get the rings to seat then you won't have any problems. What kid of rings did your builder install ? Also the heads won't cuase overheating but the smaller exhuast ports will cuse a power loss. Do you know what head casting #'s you have ?

WETTE VETTE

One good thing about boats is an unlimited supply of cold water to cool the motor!

88Fountain

iTrader: (1)

The Cleveland block is a stouter block but not in cylinder wall thickness. Windsor cylinder wall thickness is thicker. That along with the oiling system on a Cleveland is the reason they went away with these blocks (not to mention the cost for the heavier cast iron block). You can pretty much get anything for a Windsor now, not much new for a Cleveland. Ran both for many years.

Strip Poker 388

iTrader: (6)

I don't believe the .060 bore will make it run hot in a open system in a boat.They lake is a big radiator

Just remember all the Mustang guys use to the use the 351W motors because of the 9.500 deck height .Before they came out with the SVO blocks . They would stroke them and super charge ,NOS them to death .Nascar use to use the Cleveland block 351c as the Boss mustangs also. It had a 9.200 deckheight . The 289-302w block I think? was 8.900.

The best I can remember the truck 351w heads would have a better port.the exhaust was still bad on them .Also watch out for the different cc combustion chambers . This will change your compression ratio.

Maybe there some Ford guys that could chime in more on the heads for ya Dont down grade if ya can help it .You might try finding some used aftermarket heads ?

Sounds like your project has gotten drawn out I hope ya get it going soon!!

Rob

cstraub

I agree with Vette and Strip. The Windsor engines are thin cylinder walled blocks, both 302 and 351W, and can run hot in automotive applications. Since this is a marine applicationa and I am assuming it is raw water cooled you have the largest radiator you can buy.

Strip nailed it, do worry about the exhaust ports, you need to worry about the combustion chamber size. Ford Windsor engines have tons on different casting numbers and sure as hell don't want a head that was for a 302 on your 351. I would highly recommend CCing the heads to see what you have. Long run a set of Windsor SR. World products may be just what you want and give you some added punch.

Chris