You guys are hard core. I've learned more in this thread about building up a cummins than any other so far..

I saw on the BigBadDodge site, he has a set of Aries pistons for sale..
quote:
Used forged Aries pistons, .020 over 11.1 compressions, in great shape $1,000 for the set. These pistons retail for $1,761.54 before tax. Buy these and save almost $800.00

 

For doing things like torquing down the crank for plasti gauging, I would have it on a firm level bench, or the ground. Early on in my engine building attempts I was shown how much variance you can have with the engine not being supported all the way across. For just about everything other then torquing, engine stands are invaluable.

I couldn't find a picture of my plate that I used, but it was basically a rectangle that was 3/8"s plate a bit taller then the 4bolt pattern for the engine mounts, and then the long side of the rectangle when down the side of the block. the four more holes were drilled. All it did was offset the engine just enough that it would clear the stand so I could flip it over with the help of a friend. You had do use the pin to hold it in place once it was there though.

 

We could build a log mani with mild steel sch 40 elbows and pipe, with a T4 flange and provision for an external gate for ~$200. My buddy Aaron has some really good prices on flanges, and will cut anything I can dream up. http://store.weirtech.ca/catalog/

 

X2, i cant wait to see this beast!

 

LOL,, me either ,,, LOL.

 

Question of the day guys, would you guys run 11:1 compression ratio for a drag race truck? I have a hard time thinking about going lower than 15:1. I know its about cylinder pressure, but there are tradeoffs? If you ran the 11to1 pistons, I would run methanol spray with 50:50 mix, for low boost pressure from 15 to 40psi, just so the engine would spin-up faster and spool the big turbochargers. Of course nos would help as well. I just have to get my mind around if the low compression would work decently. You see puller doing that, but they can sit there until the turbocharger lites. Drag racing is different. You have to stage around 25psi to 30psi area, then its foot on the floor. 10 seconds later(or less) you cross the end of the track. Would a 11:1 motor work?

 

If it was a pure drag truck, like pro mod, then yes. Other then that youtube big bad dodge, and you can see what they idle like. You almost need a sigma pump worth of fuel to make it worth wile.

 

Kevin,

Sorry to hear, but I know your pain!!

Just a word of advice, your $5-7k budget won't get you much further than basically rebuilding what you already had.

And definitly use either forged or aftermarket rods!! If it weren't for the 12V rods in mine, I would be looking for another block right now

 

11:1 too low IMO.


I remember reading a write up about a big fuel low compression Ppump truck in diesel power a long time ago. I can't recall the actual compression, but it was around there somewhere. anyways. owner said in the article he can't start it with out a hoot of ether. compression too low. but runs great on the drag strip.


trade offs.

 

Kev, you'll make a pass. Just hang in there buddy. I want to see what this truck does for the entire run.Its gonna be a nice ride buddy.

 

fyi, Princess Auto has a stand thats good for 1250 lbs ($100), as well as a bigger one thats good for 2000 lbs ($150).

 

i disagree. theres no HD engine anywhere that needs to be supported for torquing like you describe. we've got all types of engine stand in the shop at work. you get a Series 60 or 8V-92 hanging off one side of a stand. torque it up no question about it. straight to the dyno. run the bag off it.


maybe your honda ventures or small engines sure probably. not something with a block the size of a B cummins or better. they get hung 1 side 2 sides no sides. they all get torqued that way. never made a difference.

 

The engine that it was demonstrated on, was a bbc 454, but Luke I have no doubt you build more engines a month then I have in my life time. I have put together exactly one cummins bottom end before. A number of sbf, sbc, sbm, honda, vw, mazda, ect... But I am by no means an expert in HD engine building, or engine building in general. There is always a big difference in some one who gets paid to do something vs some one that has to pay to do something.

EDIT: I have never tested this theory since it was shown to me, I always just put the engine on a firm surface to check clearances.

 

Thanks Greg! My budget is alot higher than that.. I am just hoping to sell the extra parts off of this new engine to cover the purchase of it. I just want to make sure that I buy the best, without going stupid, if you know what I mean.

 

I think that going for the lower compression ratio, its just so you can make a full pass without breaking something. The biggest trick is to build maximum cylinder pressure, that the cylinder can take and survive to make more power.