Modern pistons for a 3-main B-series engine

mjamgb

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• Mar 18, 2006

• #1

I'm rebuilding my 3-main MGB engine to go in a Magnette. I am going for smoooooth power and reliability. I want a modern piston/ring design rather than the monster lumps the factory supplied. Anyone have a source they really like or advice?
The engine will have several modifications for reliability including lightening, balancing and upgrading as necessary (I've done a few of these in the 5-main format).
No, 10,000 rpm isn't in the cards, just smoooth cruising. /ubbthreads/images/graemlins/angel.gif

 

DrEntropy

Great Pumpkin

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• Mar 18, 2006

• #2

If you want to go with REALLY spiving jugs, Wiseco, in Mentor Ohio will MAKE 'em any way you want. Not cheap, but decidedly "custom."

 

OP

mjamgb

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• Mar 18, 2006

• #3

Ja, Arias, Keith Black, Ross, etc. will all do that, I was hoping someone has experience with "off the shelf" stuff that wasn't cast in India from the same molds used since I was born.

 

aeronca65t

Great Pumpkin

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• Mar 18, 2006

• #4

Try AE Pistons. A set around 9:1 comp ratio would be nice for a street car (but you can get higher). Here's one source that probably has them (but AE are pretty easy to find from various suppliers):

https://www.aptfast.com

 

DrEntropy

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• Mar 18, 2006

• #5

AE seemed too "mundane", from the way I read the post... but they're all I've ever used in B engines. I got a set of jugs made for a V-12 Ferrari from the Mentor outfit, faster and cheaper than from It'ly.

Sorry for the gap in my understanding there, Mike!.

 

Dave Russell

Yoda - R.I.P

Gold

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• Mar 18, 2006

• #6

IMO, Deves makes about the best rings that you can get.
https://www.deves.com/about.html

As far as pistons, Venolia makes some of the strongest, lightest, most precise pistons that you can get. However, they are forged instead of cast & require a bit more cold clearance than cast pistons. After a very brief somewhat noisy warm up they are as quiet as any others. The price may not be that much more.
https://www.venolia.com/

I believe AE is a cast piston. Requires less cold clearance, is heavier, & not as strong. Maybe all that you need though.
D

 

G

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• Mar 18, 2006

• #7

If you want to spend that sort of dough, get something made from a hyereutectic alloy, they are low expansion so you can still run the same piston:wall clearance as stock. That way you get the benefit of a forged piston, but no slap.

They are not exactly cheap though - mine ran about 2x the cost of a set of Hepolites, and because they were custom I ended up waiting 3 months for them.

 

D

Deleted member 3577

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• Mar 19, 2006

• #8

I have heard that hypereutectic pistons (>12.5% silicone) are very susceptible to detonation failure.

Any truth to that, or is it just Chicken Little talk?

 

G

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• Mar 19, 2006

• #9

I've only ever heard of it being a problem for high boost turbo engines with poor detonation control. I doubt that that's what we are talking about here though.

 

OP

mjamgb

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• Mar 20, 2006

• #10

OK, so, is the consensus that ALL new pistons are of a new design (including 3-main units)? Perhaps I'm showing my ignorance but are the 3-main pistons actually different from the 5-main units other than wrist pin? Maybe It's not the issue I thought it was. I know the rods are two different flavors. If the wrist pin diameter is the same as the 5-main pistons then I should be able to use them?

 

T

trfourtune

Jedi Knight

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• Mar 21, 2006

• #11

JE makes anything you want and they have a forged street stock alloy that has a lower expansion rate that is designed exactly for the hot,hottest, pump gas, street motors. those are what i am considering for my 10:1 comp triumph tr4.
rob

 

M

Matthew E. Herd

Jedi Warrior

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• Mar 21, 2006

• #12

If it's any interest, my pistons are JE forged (and it took forever to get them). But I am running a 1500 midget at 10.5:1 + CR and using Sunoco Ultra 94 with absolutely no problems. 93 Octane works fine in a pinch too. No problems with knocking, and the car really screams.

 

billspohn

Jedi Knight

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• Mar 22, 2006

• #13

No, you can't run 5 main pistons in a 3 main engine. You need the correct wrist pins.

I LIKE the 3 main 1800 engines a lot. I've raced several cars with them.

 

OP

mjamgb

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• Mar 23, 2006

• #14

So, Bill, what pistons do you use and are you happy with them?

 

billspohn

Jedi Knight

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• Mar 24, 2006

• #15

I have run AE (Hepolite) .080" over cast in my 3 main back-up 10.5:1 race engine and never had a problem. Great for the street too.

For the race engine (MGA Twincam) I use custom built Ross Racing forged as with 12:1 and a 7800 RPM red line, you don't want them coming apart on you. That's overkill even for a hot street engine though.

 

DrEntropy

Great Pumpkin

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• Mar 25, 2006

• #16

I've had NO problems with AE's in five main mills, even built some 10.5:1 "street" engines with 'em too.