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chrismorse chrismorse is online now
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Join Date: Apr 2011
Location: behind the redwood curtain, (humboldt county) california
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CP or JE pistons, 74 2.7-2.8 with 10.5 compression

Evening Gents,
I, (with some serious assistance from Trackrash) am about to get into my old man's 74 engine - hopefully top end only.
My question is which pistons, CP or JE, with a cr of 10.5.
During this 10 year restomod, i have gone through the suspension, brakes, steering, pedal cluster, seats, new SSI, alum clutch & RSR flywheel, wheels tires, duck and spoiler, rust repairs, entire fuel system, including Al's MS PMO ITBs, crank fire EDIS ignition.
The car is my dad's original 2.7, rebuilt oncce, with a top end job about 10 k miles ago. It will see "spirited road use" and a few DE's. I have tried to sharpen up the performance/responsiveness with 21/27 T bars bilsteins, Tarrett 22mm sways and HD rubber, 15x7 Jongbloed wheels with 205x50-15 Direzzionales and light clutch/flywheel.
The long block is stock spec. On seeing this, Gordon graciously offered to "Help" me to bump the CR and do the cams, since the engine was still out.
With the megasquirt, EDIS and the crank fire all in place, it looks like all i need to do is add another EDIS module, coil pack and another set of wires, (+ a bit of machining) to enable running 10.5 (from 8). Since it is unlikely that the pistons, rings and cylinders are still reuseable at 100k since the rebuild, it seems to make sense to go to 92 mm on the bore - hence my question:

Carillo or JE for the pistons???

Some old posts seem to indicate that both are of the same alloy and costs are close.

How do they compare on weight, durability, cost, performance???

This is not a serious race engine, no flow work on the heads, (only going from 32 to 35-36 on the ports, (with cc-ing to confirm cr), Torquey cams - roughly DC30-40 finishing with a scart muffler.

Availability is also a consideration - who has them??? I'll likely need to ship them to EBS, or ?? to get the old cylinders bored to 92 and re-plated????

Approaching 74, i have recently, (& fairly frequently) found that i do not have all the answers - this devastating revelation reminds that i should seek advice from those who have gone before and done it.

With considerable humility, I welcome all advice,
chris

Last edited by chrismorse; 12-30-2021 at 04:39 PM.. Reason: oomilitay
Old 12-30-2021, 04:36 PM
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