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View Full Version : Can you get 18:1 pistons?



Eric1962
12-05-2018, 18:04
I have been researching this all day and 18:1 compression pistons seem very hard to come by. Does anyone have a set .20 or possibly .30 over that they would like to sell?

Thanks
Eric

Eric1962
12-05-2018, 18:16
My findings so far:
Bostic Motors advertises them, but does not have them in stock... meanwhile amazon still has an $800 CC charge pending... lovely. Same thing... they advertise them on ebay, but they don't actually have them. I sent them an email and they plan on having more in Feb. I can't wait that long.

Kennedy diesel has special order 8 weeks... could maybe wait that long, but a little over my budget.

Peninsular is gone and unique diesel does not show them on their site, although I have not called them.

I might try calling Mahle... worth a shot.

If anyone has any other suggestions, I'd love to hear them?

Thanks
Eric

Kennedy
12-06-2018, 07:58
Mahle dropped them a long time ago and I haven't made any in probably 10+ years now. I have the original pattern, but when you add up piston, machining and coating costs it just gets spendy.

As for Bostic I'd look elsewhere based on the feedback that I receive regarding their stuff.

arveetek
12-06-2018, 11:07
Looks like the aftermarket support for the 6.5L is really dwindling. Most of the 'regular' suppliers are either not supporting the 6.5L anymore, or have actually closed their doors.

I had the Diesel Depot in Georgia (the Avant family) make me custom pistons about 12 years ago. I was really pleased with their products and services, but alas, they too are out of business.

You can never go wrong with Kennedy's products and support. He's top notch. Just like everything else in this world, you get what you pay for.

Casey

ronniejoe
12-06-2018, 12:12
With John's permission, I made a set similar to his for another member on this forum. I can have more made, but they are costly and there is a long lead time.

http://www.schoolcraftpowertrain.com/Pictures_&_Data/Reduced Compression Piston Small.jpg

Eric1962
12-06-2018, 12:49
Very interesting... Bostic claims that they have more coming in Feb. I trust in you knowing they are discontinued, which means Bostic is getting Mahle knockoffs. If that is the case, I lucked out by them being out of stock.


Mahle dropped them a long time ago and I haven't made any in probably 10+ years now. I have the original pattern, but when you add up piston, machining and coating costs it just gets spendy.

As for Bostic I'd look elsewhere based on the feedback that I receive regarding their stuff.

Eric1962
12-06-2018, 12:54
It sure seems that way. I too was trying to find the Diesel Depot the other day and like you mentioned... gone.
I understand that you get what you pay for, but for me if costs get too high, it just makes sense to put in a cummins.
Thanks
Eric


Looks like the aftermarket support for the 6.5L is really dwindling. Most of the 'regular' suppliers are either not supporting the 6.5L anymore, or have actually closed their doors.

I had the Diesel Depot in Georgia (the Avant family) make me custom pistons about 12 years ago. I was really pleased with their products and services, but alas, they too are out of business.

You can never go wrong with Kennedy's products and support. He's top notch. Just like everything else in this world, you get what you pay for.

Casey

Eric1962
12-06-2018, 13:03
Nice work, and thank you very much for the offer!
About the most I'd want to spend is $800 and unfortunately I need to get this engine built as soon as possible, although I have at least a month, probably longer, before I will need them.
I have friends in the machine shop business, I can ask them and see what they think. I'm not sure how you made yours, but they do have large CNC machines, which makes me think they could knock them out pretty quick, but I know nothing more than what I remember from High school machine shop many many many years ago, lol.


With John's permission, I made a set similar to his for another member on this forum. I can have more made, but they are costly and there is a long lead time.

http://www.schoolcraftpowertrain.com/Pictures_&_Data/Reduced Compression Piston Small.jpg

Eric1962
12-06-2018, 13:49
Are the mahle .010 shorter pistons still available? If My block does not need to be decked, then from what I have been reading I can get the compression ratio lowered a bit with a thicker head gasket. Not optimal, but might have to be good enough for this build.

Thanks
Eric

Kennedy
12-06-2018, 13:53
Are the mahle .010 shorter pistons still available? If My block does not need to be decked, then from what I have been reading I can get the compression ratio lowered a bit with a thicker head gasket. Not optimal, but might have to be good enough for this build.

Thanks
Eric


You are looking at $600 for a set of pistons/rings. Yes I believe the .010 "topped" units are still available. You could see if there are still pin bushings available in 20/20 and then use a fixture to try to get another few thousandths out of the rods while equalizing the length.

ronniejoe
12-06-2018, 14:17
I've had custom bushings made to offset like this. I think the most I've gotten is about .010" change in length. I bought a set of the 20/20 bushings a couple of years ago or so, but didn't use them. Had the custom ones made instead.

sctrailrider
12-06-2018, 15:33
What bore size are you wanting, I will be running 13 new sets in a couple weeks and will be giving them a 3 side ceramic coating, and I also have Kennedy's permission to copy the design..

Eric1962
12-06-2018, 15:55
Another good idea... I planned on bushings to equalize rod length anyway.

JeepSJ
12-10-2018, 17:53
With John's permission, I made a set similar to his for another member on this forum. I can have more made, but they are costly and there is a long lead time.

http://www.schoolcraftpowertrain.com/Pictures_&_Data/Reduced Compression Piston Small.jpg

And I think my machine work has taken as long as the pistons...

sctrailrider
12-23-2018, 15:58
I just finished 2 different styles, 18.0:1 with valve pockets, 18.5:1 without pockets.. 3 side Ceramic coated.



I have 5 sets of each style listed on ebay..