ForkedUp, the hole on the right side of your motor plate was intended to be the alternator pivot. You will have more room for the alt on that side as the exhaust on that side sits an inch or two further back. You might even consider using one of the mini- or ultra-mini alternators to help with the fit issue. It is nice to see you have a marine-equipped version of the GM 10SI alternator, though.

Sorry. NOT arguing with the article. Never was. I think it is a nice piece showing how the formula was derived. I was doing nothing but trying to clarify that NO signifigance, other than mathematics, should be given to the 5252 number. It is clear you do not understand my point. Metric system was, and I seem to have to repeat myself, brought up only to help illustrate that fact. No more, no less.

Don't misunderstand . I was NEVER being a critic. I was trying to point out the insignifigance of the "5252" as far as how one goes about building or setting up and engine for any specific purpose. That number has been misused and misunderstood by far too many individuals in the past. As I tried to say before, that "constant" only applies to one set of measurement "units", in this case Horsepower and Pound-Feet. If the relative size of the "units", not the number, changes, so to does the "constant". If Watt had chosen a different number for his definition of HP, then the  number "5252" would not be the "constant" in the HP/Tq formula. The example of the metric units should make that quite clear.

I'd still like to know what site the article came from to see if there is any other interesting reading.

Yeah, when he told me that, I wondered why he had informed me it was mine if I wanted it, considering he had someone else interested who had responded before me. Seemed odd.

If what Rexone posted on Powerboats.com a week or two back is correct, you should have access to your PMs when the site comes back up.

By the way, the seller had originally told me the handle was mine if I wanted it. When I replied shortly after that, he told me it was sold. Gave me kind of bad feeling about the guy.

One of the most entertaining threads ever in Just Jets. Love that look on 'lil "Test Unit" Busby's face. Gotta be thinking, "what the f*** is Dad trying to do to me?" If I recall, the M-O-M unit wasn't all that pleased with the "safety gear". I still think the experiment would have gone off better with a lighter weight pilot. A neighbors dog or cat, taped to the skateboard,  would have surely been more fun to watch..........

I am thinking Aggressor but I want your guess..

That would be my thought as well. Can you measure the pin angle?

Before you start drilling, check with your machinist to see what it would cost to set the manifold up in his mill to drill & tap the holes. Might not be that expensive and it will ensure that they are all done in line and at the same angle(makes it look a lot nicer )

This looks like a Rogers Dragstar ..... maybe.



-beerjet-

If you take a close look at this pic, just ahead of the trailer fender and below the tail light of that Econoline, you can see that this hull has sponsons, making it a jet hydro. The paint job seems reminiscent of Sanger with the narrow color bands with fades, but the Sanger jet hydros that I have seen were more of a "tunnel" hydro. This one seems to have just a very small(1/4"?) dropped chine. Of course those might just be the result of reliefs in the hull for recessed cav plates? Would be nice to see more pics........Hondo also made a jet hydro, but it had a much more pronounced gunwale, especially in the rear, where it kind of flared upward. It also was more of a tunnel-hydro design, I think.

Tom, if you haven't already torn the pump down, could you measure the clearance at the front of the impeller? Curious to know how loose those were from the factory. Pic seems to indicate a pretty wide gap.

. .... Didn't look like it did much damage to the impeller.  Am I right?

Although a person could spend the time(and money) to reshape each the leading edges of those impeller vanes, I'd say there is enough damage there to consider that one toast. Don't forget the likely wear/damage to the wear ring surface. New aluminum impellers are relatively inexpensive.

We had a lot of fun in my buddy's Tahiti 16 back in the early 80's.

The 425 and 455 Oldsmobile blocks are identical all the way down to the factory boresize. The crankshafts are interchangable.

The blocks are not "identical". Can't recall if all, or only early 425s had a different lifter bore angle. Not a major difference but one that should be considered if expecting the most out of a cam choice.

The crankshafts are NOT INTERCHANGEABLE. There is a .275" difference in stroke so they obviously wont "interchange". Perhaps you should have said that either crank will fit either block(although the 425 may require clearancing at bottom of cylinders for a 455 crank/rod combo), but displacement will be determined by the crank chosen, and that the appropriate piston/rod combination will have to be used. The rear flange of early(1965?) 425s has a different bolt pattern. The 455 PTO will not fit this different pattern. I think Glenwood still lists the 425 item.

The 425 Olds all came with a beautiful forged crankshaft. If you have not yet seen one of these cranks, you will love looking at it. I think you should use the 425 crank, absolutely. By the way, they have huge rod journals and you can offset stroke these Olds 425 crankshafts and have a nice forged stroker crank. Aftermarket piston/rod combos will need to be figured out by you, then stroke the crank accordingly. By the way, I'd recommend using fully-grooved bearings in your Olds boat motor so as to establish continuous oil feed to the rod bearings.

Great idea if one is building a motor from scratch, but it is a pricey proposition as it will require a non-stock combination of rods and pistons. For someone just trying to put a 455 back together as a 455, the 425 crank isn't going to work without being offset ground to the 455 stroke. This will still require the use of non-stock pistons/rods. If just using the 425 crank as is, it would still require the use of 425 rods/pistons.

Its too bad that the Olds strokers were never as common as the Ford or Chevys. I always wanted to build a bigger Olds based on an offset ground 425 forged crank or even an offset ground nodular iron crank(had one in my 455).

The last pro I know who was doing that conversion was Jack at MPD in Costa Mesa. he used to do them in the off season but I read a while back he had discontinued that service. Considering the cost(approx $350), a used split bowl is probably a less expensive alternative.