New School Custom Pistons

[spmdr]

Now that I have settled on a "New School" Rod, I need Custom "New School" Pistons, with a .787 pin.

Looking on ebay for pins, I found these interesting pistons, that use that small pin.





Too bad they are a bit too big for an Alpine.

I'll most likely have a more old school looking piston.

But who knows...


I'm looking at/for a ring package like this:

1.2 mm top
1.2 mm second
3 mm oil

 

[Jay Laifman]

Hi Dan. Per another post, when I had my engine built, the guy who helped was a Lotus racing expert. He had a set of rings that he favored - from his Lotus engines. To use them, it meant I had to go to 55 over. So that's what we did. It makes for 1780 cc. You may want to look into what the Lotus guys do for their custom pistons. I'll be you could find some slick stuff there that could work.

 

[spmdr]

The rings I'm looking at are a mix of my choice for the top ring size (1.2mm)

and the piston guys choice for an oil ring (3mm).


Top rings have been coming down in thickness.

Old school was happy with 1/16" (1.5mm)

New school likes smaller, around .040 (1mm)

I like to split the difference with .047 (1.2mm) for a bit more durability.


The ring package I'm looking at is common in the Toyota 1.8 L with a STD bore of 3.228 (82mm)

The Hastings # is 2C5087S 1.2mm top, 1.2mm second and 3mm oil.


BTW, even though this is in the "Racing" section, I expect the pistons and rings to work fine on the street, as well.

Based on what I have seen, it wouldn't take much to be BETTER than stock Alpine rings!

My next choice is bore size, 82mm or 82.5mm for the first set of pistons.

 

[spmdr]

Jay, can you get more info about the Lotus rings, like the width?

.055 over is 3.265? A little bigger than I want to go, to start.

 

[Jay Laifman]

For point of reference, my bore is 82.8mm.

 

[Jay Laifman]

Just crossed posts. The guy who did the engine is actually the guy who is helping on the Elva race car we are restoring. I'll ask him what he used.

 

[spmdr]

Jay, do you have the info on the pistons? Who made them?

 

[Jay Laifman]

We custom ordered them. It was either Jahns or Arias. I think it was Jahns. I just spoke with the guy who did them. He doesn't recall which special set of rings he used in those days - but said he would have got them for Dave Bean, a Lotus parts shop. He said regardless, he would get a modern narrow ring pack now and use JE.

 

[spmdr]

I bought Pistons from J&E in the past but that was a long time ago,

and like a LOT of companies, they have changed a LOT.

I have not recently looked at J&E pistons but at this point I needed to cover that base.


Based on their web site, J&E clearly has more forging types available than other sources,

even though the salesman I talked to seemed to be quite ignorant about forging availability.

One thing I did find out, J&E is NOT the best priced!


I was not impressed with the J&E CUSTOM piston order form!

I didn't see any place to spec the Location of the ring grooves,

AND NO place to even SUGGEST special NOTES to consider/build to.

J&E's order form asks a lot of info about the engine

and less about the actual piston you want.


The jury is still out on J&E, but it's not looking good.


I have been referred to a new Piston manufacturer in Long Beach, but they are weak with their phone coverage...

 

[spmdr]

The Racetec custom Pistons are here!

...to go with the EXtra long rods...

 

[spmdr]

For the record, the New School pistons have these weights:

Piston ....... 308g

pin ..... 90.5g

pin clips .....1.5g

rings ...... 19g

total .........419g


stock:

piston.........445-460g

pin .............152-156g

clips...................1.5g

rings .................36g

total.........634-654g

 

[alpine_64]

Not a bad saving.. I assume the weight reduction on rods is even better... Combined that will be a lot less reciprocating mass

 

[Five Reviver]

For the record, the New School pistons have these weights:

Piston ....... 308g

pin ..... 90.5g

pin clips .....1.5g

rings ...... 19g

total .........419g


stock:

piston.........445-460g

pin .............152-156g

clips...................1.5g

rings .................36g

total.........634-654g

My comp engine has just been stripped and it’s rebuild time with sleeves bringing the bore back from 0.060 to OE or close (82mm seems a good choice).

For rods and pistons I might enrol in the New School. Would you consider sharing the spec or order sheet of your new school pistons? By my reckoning they have a compression height of 1.211” or thereabouts?

David

 

[spmdr]

Yes CH is 1.210.

That CH was planned for a Stock 1725 stroke (3.250).

The only thing changed from the original thinking, is the ring package.

The New piston guy talked me into smaller rings, 1 mm top, not 1.2 mm.

About the only other dimension of note is the distance down to the top ring.

It's .300 to leave room to notch the block for Big exhaust valves if needed.

And for the record, these pistons go with the L O N G Rods here:

https://forum.sunbeamalpine.org/index.php?threads/h-beam-racing-rods.29544/

DW

 

[Five Reviver]

Many thanks for the information. I spoke to A guy at Racetec who is able to supply them but I would need to get a US freight forwarder for my Australian order. That’s not out of the question at all but can anyone suggest manufacturers in Australia?

 

[alpine_64]

Many thanks for the information. I spoke to A guy at Racetec who is able to supply them but I would need to get a US freight forwarder for my Australian order. That’s not out of the question at all but can anyone suggest manufacturers in Australia?

Is this David W?

 

[Five Reviver]

Is this David W?

Hi Michael. Yes it is

 

[Five Reviver]

I now have these RaceTec pistons and the Eagle rods to match. Now ready to have the crank machined to fit the rods and have 82 mm sleeves fitted to the block.

 

[spmdr]

Wow. It took me a LOT of months to get those pistons out of Racetec, congrats!

I was going to ask Racetec how long it would take for the next order,

of that same piston, but forgot to ask.

David, are you doing a 1725?

I have talked myself into a stroked 1592, because of the Steel crank.

DW

 

[Five Reviver]

Ah, it’s all thanks to you DW for doing the R&D and driving production. Now they have a part number. In the end though they wouldn’t deal directly with me and I had to go through one of their two Australian agents, which was fine. Once I confirmed the order and paid I had them in 22 days. Extraordinary really.