View Full Version : Building an ET2 motor...

01-27-2011, 04:32 PM
So i'm going to take the dive...

I'm posting right now because at the end of next week or so, i'm going to start buying parts to rebuild my semi rebuilt motor.

Quick history... I bought a motor 2nd hand from a shop that rebuilt an 85 Spec ET2 motor (a18). had new pistons, new head, and remachined stock rods. The crank and the block are also the stock. Other than that I had no other information. I have a set of dual DCOE 45s weber carbs on it, and one of the rod bearings spun during the break in period.
So basically i have to get the stock crank remachined but i've decided to do the LS rods/pistons in my ET2 motor.
Figured I'd post up asking for advice for things i should need to measure and look out for before i go spending money on nearly non returnable things...

My bore currently is 81mm so i'm looking at the 10.7:1 forged pistons and rods...
So give me some advice and 89T i'm looking dead at you!

Vanilla Sky
01-27-2011, 09:12 PM
Have you thought about an A20 bottom end with an ET head?

01-27-2011, 09:57 PM
I have, I even have an a20 block that in great shape in the garage. But my head on my current motor has that weird head pattern that was only used on the 85 model et2. So my head will not fit on my a20 block, which SUCKS!

I'm also hoping that the only machine work i'll actually need is just getting the rod journals remachined... the block for sure i perfect... still has the cross hatching on the cylinder walls. the motor literally only has 800 miles on it

01-28-2011, 10:18 AM
Here are the pistons i'm looking at...

and here are the rods i'm looking at...


Do you guys think i should try and shoot for higher than 10.7:1? I saw some wiesco pistons that are in the 11.5:1 range...

I'd go higher compression for sure, but i'm worried about my valve clearance... I using the 285 delta regrind with 11mm of lift...

Wiesco over JE and opinions on that?

01-28-2011, 10:32 AM
Every single machinist I've talked to has said don't machine Honda cranks. You take off the hardening, and then you've gotta get them rehardened. It's expensive enough that you might as well find yourself another crank that is in good condition. I think your A20 crank might interchange.

01-28-2011, 10:36 AM
All A-series cranks should interchange, with the exception of the A16 (good luck finding one of those anyway lol)

Vanilla Sky
02-26-2011, 01:12 PM
Moved per user request.

05-05-2011, 10:27 AM
Would be an interesting engine though 1.6 crank and rods with 2.0 pistons wonder how that would rev like! ET1 head would be best though for revs rather than A18 head would also have a mad compression ratio as well! I had a ET1 head on a ET block bored to 82.75mm but with A20A1 pistons unfortunately and that engine was a rocket revved to 7.5k rpm with 275 degree cam, stock size valves, and stock rods, shame the rod bolt nuts came loose and killed the block! :(
Would have been really interesting to see what it would have been like with big valves, custom header and 2.5" exhaust as well as A20A3/4 pistons would have easily made 220-230bhp me thinks! as it was already touching 200bhp!!
Damn miss that engine one that made the car hit 14.5 flat on 1/4 miles even with slipping clutch and crap road tyres!

05-06-2011, 06:05 PM
All A-series cranks should interchange, with the exception of the A16 (good luck finding one of those anyway lol)

They used to be everywhere up here.

05-07-2011, 11:18 AM
Think bigger is better still lol!
Having a A20 revving to 8k wasn't that hard think it would be a little scary if it went any higher that and I'd need a new rev gauge! lol! well need a new speedo gauge too as well only goes to 145mph!!