516 in D 21 puller QUESTIONS

I was toying with doing that to a 426 to get it down to 410 cubes many years ago. My plan was to bore the existing sleeves slightly (leaving a step on the bottom inch), and lightly pressing in a 1/8" dry sleeve blank inside of the wet sleeve and then boring to the correct undersized bore to meet the cube requirement. Then, the pistons were going to be turned down in a lathe, less than 1/8 " off of the diameter, which is only less than 1/16" material removed. Not being cam ground didn't bother me, as they were going to be a loose fit compared to stock anyway. Might have had to deepen the ring grooves a little and then just find a set of rings, which wasn't going to be an issue. Reducing the 426 down to 4.125" on the bore made it 400 cubes, so I wouldn't have gone the full 1/8 reduction. Stock head and valves would have still been used. 

Your range of 900 - 1300 HP is a wide one. Maybe if you posted the pump and turbo limitations it would be helpful. None the less, getting to 500 cubes is no hill for a climber with a 426 block and to me would be one hell of a lot easier than fitting a 516 into the D 21 chassis, then have to re cube it. Also, I would hope a 426 of any cubic inch size would do more than a 5.9 Cummins will do. I realize the Cummins idea is spawned from sponsorship money, but to me seems like the idea which would yield the worst results. I assume the 400 series IH and Deere engines are in this class. They would eat up and poop out any 5.9 Cummins that was equipped with the same turbo and pump.

I'd save the $4000 on the core engine, use a 426.  If you can only run to 480 cid then I really don't think that the 426 would be much or any disadvantage ran at 426 cid.  Seat time and tuneing will do more than another 54 cid ever will. 

Looks like the reason why is money... 

Well, in my mind there are a few reasons: Transplanting a foreign engine into a chassis it was not made for seems simple enough on the front end. The reality is any time you take on a job like this there are many "unforeseen things" that come into play. The obvious one is a flywheel, clutch, and back plate and making it all work with the starter on the engine. Second is how does the front plate fit between the frame rails. Now those two alone don't seem like that big of a deal and they aren't, but the time and money spent doing just those two things could be better spent on the engine that was made to fit in the first place. The list would be different for every cross breading, but things just don't happen as easy as they look to begin with.

Next would be finding parts for the 516 if something failed or you need a spare. Much tougher than the 426 I would assume.

Next, who say's the 516 is worth a damn for higher performance? I don't know what the heads are like, same goes for the rods, crank, etc. At least with the 426 there would be a more than a few people who could help in making it powerful and reliable. For example, try to find fast ratio rocker arms for a 516. Good luck!

And yes, it all boils down to money. I would say with a fair amount of confidence that you would spend less on a 480 C.I. 426 than you would jacking around with 516 and end up going farther down the track.

My two cents.

Edited by O.P.S. Heads - 25 Jun 2013 at 9:11pm

Can you call me Steve at 360 393 7760 cell.

I would think some of the 344 parts would interchange since it's the four cyl. version of the 516. Best thing to do is try to find that guy that has actually done it and still pulls with one. Heck look at the 6030 deere motor it was a big piece of crap but now they make decent pulling motors.