Which Block would you Use?

[Jackson1320]

I think I or others asked the question on another forum, how is it possible to sell pistons pins and rings and NOT have to check the balance? It assumes that the piston/pin/ring you're removing has the exact same rotating mass. Which as we know isn't always a good assumption (hence the need for the builder to weigh and pair and make any required adjustments to the counter weights).

I'd be shocked if you found 8 sets of pistons and gear that weighed the same (or within the comfort level of most builders). (I'm talking about the ones on an existing motor).

Ford does not balance there engines. They built balanced and blue printed the first few engines. Now they just have the engine built to the blue prints. They have every part built within a tolerance. If every part is made within tolerance then the weight will be within tolerances set by ford. Mahle just makes pistons to match fords tolerance/blue print

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[Jackson1320]

http://www.modmaxracing.com/mobile/Product.aspx?id=973

https://diamondracing.net/i-6926-diamond-pistons-30702-8-ford-modular-5-2l-voodoo-series.html

https://www.cnc-motorsports.com/je-pistons-345870-gt350-voodoo-5-2l-modular-dome-3-701-bore.html

https://www.teamjdm.com/manley-gen-iii-coyote-pistons-2018-5-0/

https://www.modularmotorsportsracin...ge=product_info&cPath=4_30_31&products_id=754

 

[schmeky]

You can see on the underside where metal was removed on the Mahle pistons to match the weight of all 8 slugs.

I would go with what the tech guys at Mahle have told me over someone's opinion.

 

[80FoxCoupe]

That Mahle kit looks like standard 5.0 93mm bore. Do they make one for the 5.2 94mm Bore size?
I've raced and built my own motors for everything from NHRA Stock Eliminator to Super Comp, you always check weights on every component and balance the assembly as needed for the application.

Have you ever checked the balance on a stock assy? A pal owns a machine shop, and I'm sure of the specific details but I know that LS engines are real bad for being out of his tolerance for balance from the factory. He rattled off a handful of other OEM engines that are the same. But at the end of the day they all still run, and run smooth. Just goes to show you how far out of balance and assembly could be and still be fine. As long as all the components fit within the tolerance stack, it gets assembled. That's how mass manufacturing works.

 

[Angrey]

You can see on the underside where metal was removed on the Mahle pistons to match the weight of all 8 slugs.

I would go with what the tech guys at Mahle have told me over someone's opinion.

I'm not concerned about whether they matched THEIR product, I'm talking about any matching that was done on the rotating assembly they're going on as a replacement.

And you're free to go with whomever you will, but have you ever considered they're position is conflicted (i.e. they're in it to make money)?

I'm simply asking the question. If the answer is, it'll work just fine, so be it. Just doesn't make sense that every OTHER engine builder wants to mass and match rotational parts and ensure that the counter balances offset.

At the end of the day everyone is perfectly free to build their motor however they choose.

Can you slap a tire on a wheel and run it without balancing it? Sure, and the tire may be perfectly balanced, but that doesn't mean the rim with stem and sensors is perfectly balanced before you do a DIY swap.

 

[olaosunt]

That Mahle kit looks like standard 5.0 93mm bore. Do they make one for the 5.2 94mm Bore size?
I've raced and built my own motors for everything from NHRA Stock Eliminator to Super Comp, you always check weights on every component and balance the assembly as needed for the application.

They make one but it’s for the voodoo . shorter CH than the coyote piston since the voodoo crank has a slightly longer stroke (3.661 vs 3.650) .
https://www.us.mahle.com/media/usa/motorsports/ford-5-2l-drop-in-2020-web.pdf

They are not 2618 alloy but still forged (M412p) used in OEM applications since they are less noisy .
You can use them with a Boss crank (like I did ) but you will lose some compression (11.9) and displacement (314 vs 317 cc- so a little less than 5.2 ) . You also loses some quench . I have the combo in my 18 ... seems to work fine .
They are the same pistons used in the 5.2 Alluminator but with a 5.2 cross plane crank (same stroke as Voodoo) .

There are several after market coyote (CH) 3.7 pistons to use with the Boss crank that will keep the CR/quench and 5.2 displacement.

 

[bauern]

That Mahle kit looks like standard 5.0 93mm bore. Do they make one for the 5.2 94mm Bore size?
I've raced and built my own motors for everything from NHRA Stock Eliminator to Super Comp, you always check weights on every component and balance the assembly as needed for the application.

Yes but it's 11:1 CR, #930258601

 

[bauern]

https://www.cnc-motorsports.com/je-pistons-345870-gt350-voodoo-5-2l-modular-dome-3-701-bore.html

Also one for the Gen3:
https://www.cnc-motorsports.com/je-pistons-353907-coyote-5-0l-modular-gen-3-dome-3-701-bore.html

 

[Desert Dog]

Olaosunt, Thanks for all the great info. I was hoping there would be an off the self piston that would work. I don't mind losing that little bit of compression. I will check that out that Mahle set. I want to do this thing right the first time. It looks like a real PITA to pull the engine.

 

[bauern]

Olaosunt, Thanks for all the great info. I was hoping there would be an off the self piston that would work. I don't mind losing that little bit of compression. I will check that out that Mahle set. I want to do this thing right the first time. It looks like a real PITA to pull the engine.

Just be aware that they use a smaller pin so you'll need Voodoo rods.

 

[Jackson1320]

http://www.modmaxracing.com/mobile/Product.aspx?id=973

https://diamondracing.net/i-6926-diamond-pistons-30702-8-ford-modular-5-2l-voodoo-series.html

https://www.cnc-motorsports.com/je-pistons-345870-gt350-voodoo-5-2l-modular-dome-3-701-bore.html

https://www.teamjdm.com/manley-gen-iii-coyote-pistons-2018-5-0/

https://www.modularmotorsportsracin...ge=product_info&cPath=4_30_31&products_id=754

Each of these are options depending on which block you go with

 

[Jackson1320]

Olaosunt, Thanks for all the great info. I was hoping there would be an off the self piston that would work. I don't mind losing that little bit of compression. I will check that out that Mahle set. I want to do this thing right the first time. It looks like a real PITA to pull the engine.

Just use coyote crank Coyote rods Coyote 3.700 pistons with the highest compression available and mill the heads and/or block and you will be fine

 

[Desert Dog]

Thanks, I didn’t check the specs yet . Glad to know the pin size is different as I already have a set of Boostline Rods. i have had good luck with JE and Diamond in the past. Never had experience with Mahle or Manley other then Their Rods.

 

[olaosunt]

Thanks, I didn’t check the specs yet . Glad to know the pin size is different as I already have a set of Boostline Rods. i have had good luck with JE and Diamond in the past. Never had experience with Mahle or Manley other then Their Rods.

good choice - that’s the combo in my “spare”

 

[Desert Dog]

On your spares, do you piece them together, complete Long blocks or Short blocks. What’s the appx. cost difference ?

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