I'm looking for a part number for 12v marine app. connecting rods for my engine does anyone know where I can get a engine number or the part number?

 

Are 12V marine rods as strong or stronger than CR rods? I have heard good things about the CR rods.

Ronnie

 

Dont know. But when I had my engine built Marine rods were put in by the builder. Even the Cam followers and valves are Marine parts.

 

Everything I've read is that CR rods are weaker than the 12v and VP rods. CR rods tend to bend around 1100 hp, the latter go a good ways beyond that.

 

Is there any difference between a marine engine rods and truck rods? The stock 12v and VP 24 rods are already pretty beefy. Any body make an aftermarket lighter rod for these engines?

 

I recently heard that an aftermarket rod was available. I just don't remember who it is. I heard this while in a local performance machine shop.

 

Cunningham I believe is the maker of the billet rods, to the tune of $500 per rod. Yikes!

 

Tate, you have any specs on them or a web address? It would be nice to find a lighter rod that tuff or tuffer than the original. Its for the 6000 rpm wot hard pulls. The next issue is that darn heavy crank and pistons

 

There are pics of Cunningham rods here http://www.competitiondiesel.com/for...ad.php?t=48073

Crower makes them as well
http://www.crower.com/cgi-bin/search...&go.x=3&go.y=8

As does R&R
http://rrconnectingrods.com/store/cu...rods-p-72.html

and Woodruff
http://www.woodruffdiesel.com/Woodru...ing%20Rods.htm

TTS does as well, but have not been run in a MOD class puller to this point.


NOW, as I understand it NONE of the rods are any lighter if anything they are heavier. Also from what I understand the stock 12v rods with some balancing and shot peening will hold until the block splits in half. Guys that are running these billet rods are also making there cranks HEAVIER by 20-40lbs. I have never run any of them so this is all just "internet" info

 

Also Mahle monotherm pistons are available in small supply from what I have heard through the grapevine, but they are heavier as well, but supposedly are like non other when it comes to handling big heat. They run about $500 a hole.

 

I didn't see any rod weights on any of the sites? Looks like Woodruff sells a rod that been stress relieved and weight 10% less than stock. I would like to wind out one of these motor one day to around 6k rpm. The trick to doing that is to reduce the amount of rotating mass on both the piston, rod and crank.

 

you are right, shot peened 12v rods, a balanced lower end and a common rail block is a "bullet proof" set up. I only want to do my engine once

 

From what I have seen, MOD class pullers running the heavier pistons, weighted cranks, (rods may ore may not be heavier) ect... are still turning 5600+ rpm. Imho I think that a stock crank, stock rods (shot peened, polished, cryroed,) stock (well cut) marine pistons. All balanced, with a good fluid dampener, should have no problem turning 6000rpm. This is just bottom end only obviously. A big cam, pushrods, springs, roller rockers, ect...

That being said if guys are running twin billet hx82's you have to be turning close to that just to get them past being lit.

 

I can see the extra rotating mass helping a sled puller. I want to build a paper weight drag race truck for some low et bashing. Getting the motor to rev out faster is the trick to getting the et's down.

With all that extra rotating mass, I wonder how well the main bearing hold-up. You change the design you cause other issues with block and mains. Of course with so many engine pushing the rev limits, there may not be that many. I don't know what load limit capacity the stock main bearing? I can see it causing stock engine blocks to cracking from stress, but there only one way to find out.

On a few back up stand by power generator that I've worked on, we added an extra mass so we could get on-line and to load. We just ended up wiped most of the mains and had to upgrade the gen set in a short order.

 

BBD pulled with the above setup for 4 years before he split the block. There was a thread on his split block and then a corresponding thread on billet rods.

You would have to ask the MOD guys as far as bearing wear. I personally have never turned more then 4500rpm.