Diamond Pistons Group Buy

I'll research rods some more tonight. What alloy are the pistons made up of? Rate of expansion will impact how tight we can make the cylinder and with the skirt coatings we may be able to tweak that a bit to gain piston stability with the longer rod.

Everything I've read thus far shows pretty significant gains for longer rods. Especially when considering things like static compression ratio. I don't want to go crazy, but I don't want to be kicking myself later. I guess it's just about finding a balance.

Have you thrown this over into the v6power.net forums at all? I would think some of the 3.8 guys over there may have an interest.

Tomorrow AM still drop dead, or do you want to move it to Monday? I'll get the money to you regardless and you can just return it if the stuff falls through.
 
Dave.
I'm still intrested in this but I have somethings to ask
Do you happen to know what the tool steel is that they would be useing for pins.
 
There are other things to consider with longer rods. Sure you slow the piston down and add your compression. However the biggest gain I have ever thought of from running a longer rod would be the ability to have the piston parked longer at TDC and BDC. You could really open up a ton of new cam profiles with this sort of thing. Extra filling in the cyl and extra evac on top could give some good gains.

Chris
 
So did diamond say friday was the cutoff? I can't speak for anyone else, but if it came down to waiting a few more days or no GB, then I could wait. It is saving me some $$ so I cant complain too much. Plus thats another paycheck between me and broke. :D MY $0.02
 
I am having the block bored 30 over and plan on using the 5.996?? 351W rods.
Here is what I am thinking, but feel free to correct me if I am off a bit.
bore 3.840
compression height 1.560
compression ratio 8.5:1
but what size rings????
 
Friday is not a drop dead date. What I'm looking for is to have the interested parties step up, ask their questions, and get on with it. I'll wait till Monday.

I will ask tomorrow about alloys and weights. I forgot to ask that the first time.

For rings I'd recommend the standard size (1/16, 1/16, 3/16) or 1,1,4mm if you are going with Total Seal.
 
David D.
Ok I am back on the wagon.
Send me the following.

6 pistons, stock compressoin ratio, ..030 +.
6 of the lightest wrist pins .
6 cat rods, with bolts.
NO RINGS,Going with Totalseal rings.

When you get time send me a E-mail on my cost + shipping

My New beefed-up Lentech shipped out today.Should get it
in 4 days. So I hope to have it install by next Wednesday or
Thursday.

Thanks Randy
 
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XR7 Dave said:
Friday is not a drop dead date. What I'm looking for is to have the interested parties step up, ask their questions, and get on with it. I'll wait till Monday.

I will ask tomorrow about alloys and weights. I forgot to ask that the first time.

For rings I'd recommend the standard size (1/16, 1/16, 3/16) or 1,1,4mm if you are going with Total Seal.

TOTAL SEAL DOESN'T HAVE THE 1/16 1/16 3/16 RINGS??? ARE THE TOOL STEEL PINS REALLY NEEDED??? I DON'T WANT TO OVERKILL , BUT I DON'T WANT TO BE A CHEEPA$$ AND BE SORRY FOR IT LATER. THAT WOULD SUCK!!! I'D LIKE THE SHORT BLOCK TO BE CAPABLE OF 450-500HP. NOT THAT I WILL TAKE THE POWER THAT FAR, BUT YOU NEVER KNOW.
 
The assumption is the pistons are setup for full floating. The benefit of the Tool Steel is that they can have thinner walls and thus be lighter. Lighter is better especially when considerinig the need to raise RPM's in our motors to take the best advantage of the newer blowers coming out.
 
Regarding wrist pins. Diamond does not recommend the lightweight pins for forced induction. That doesn't mean they can't be used, just that they don't recommend it. Tool steel pins are available in stock thickness or thin wall, same price.

Are tool steel pins needed? Someone else could better answer that one.

As for the rings, stock is 1.5,1.5,4mm which is why Total Seal uses that size. Sorry I posted the wrong size above. As for Diamond offering 1/16, 1/16, 3/16, I don't know. I'll ask.

FYI

1.5mm = 0.0590551 inch
1/16" = 0.0625 inch

3/16" = 0.1875 inch
4.0mm = 0.1574803 inch
 
tool steel can be anything thats used to make tools I can make a list here but I dont think thats need.
So un tell Dave can find out what there useing we will not know whats better.
 
Mike,

If someone has the capability of properly matching cam profile to our motors in the first place then adjusting for rod length is going to be easy. The fact that no one has done an accurate job of the first part makes it a little tough to move on to the second part.

Frankly I believe there are a couple main things that demand precedence with cam selection and by necessity the rest of the parameters just have to fall where they may (to an extent). There is only so much you can do with a cam profile being that there is only one lobe profile/valve.
 
David D. here is my answer about the rods.I don't think
I can afford the rods right now.So If its ok,I would like
to back out of the rod deal.Maybe lilredstang can buy
them.Thats a great price for them.

THANKS RANDY
 
Randy N Connie said:
David D. here is my answer about the rods.I don't think
I can afford the rods right now.So If its ok,I would like
to back out of the rod deal.Maybe lilredstang can buy
them.Thats a great price for them.

THANKS RANDY

WERE THOSE THE 5.9" RODS? WOULD THEY LOOK DEAD SEXY WITH THE DIAMOND PISTONS? HMMM, I THINK SO! IF YOU DONT MIND WAITING TILL MY NEXT PAYDAY. OH HEY THAT REMINDS ME. ARE WE GETTING PISTONS?

ROLLCALL...WHO IS STILL IN?

IF WE NEED ANOTHER PERSON CANT WE JUST CHECK THE FORUMS FOR WHO IS DOING A REBUILD AND CONVINCE THEM THAT THE NEED THESE :D PEERPRESURE IS A POWERFUL FORCE!!!! I KNOW..IM EVIL..I WAS BORN THAT WAY.
 
I'm in. Just need to decide on rod length so I can offer a compression height. I'll likely go with just the pistons and pickup the wrist pins when I order the rods.

Can you get me the wall thickness of their tool steel pins? I'm curious what it is for them if they don't recommend it for supercharged or NOS applications.

I understand regarding the cam. You and I will probably need to work with Comp Cams to figure something out that's optimum once I get the heads done. I'm sure I'll be going with a new blank.
 
Keeping this alive, we have:

Mike, definite.
Scott, definite.
Scott, definite.
Randy, definite.
David, definite.
Jason, I gave him the weekend to decide.

So we have 5 people. Go ahead and send your money in. Shipping costs are not that important right now. Send $35 for shipping (remember these have to come to me and then be shipped out). If there is extra on the shipping I'll refund the difference.

Mike, the pins are .155 standard and .110 thinwall.
 
Ok, a quick look at the website www.diamondracing.net will answer most of the questions that people have had about these.

Pin materials are:

4130 Chrome Moly
H-13 Tool Steel
9310 Alloy

For us the size is .912 x 2.75" and while they don't list all the sizes on the website, they do have the Tool Steel in .155 and .115 wall for us.

Piston material is a matter of choice. You can go with a low expansion (4032 alloy) or for nitrous or extreme boost the 2618 alloy. You must choose. Typically they recommend the 2618 for boost over 10psi but as we all know we run much more than that on factory pistons. The choice is yours.

Skirt coatings will not affect bore size tolerances.

There is a form on their website for custom order pistons. Please go to that form and fill one out for your application and email it to me. mdkracing@alltel.net. Any questions post them here and we will all try to help you out.
 
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Final bore would be standard + .030. Once you have the pistons in hand then your machinist measures the pistons and bores to the exact clearance that you want to run. The block is always final bored after pistons are in hand.

Fill in all the info you know, then post specific questions here. Chances are you will have the same questions as others.
 
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