Sked

Hello fellow 1st gen lovers. Ive been wanting to post up my build up for a while, but today the worst thing happened. I have a 81 shortbed thats been in the making for a few years. Over the past few months I've been tackling the 20/22r hybrid. I had an 83 22r, which just slipped the timing chain a few years back... 05 i think. So i *thought* the bottemend was still good since it didnt smoke at all, and the cylinder walls looked in decent shape. I also had a complete 80 20r that i blew a headgasket on. So off came the head and it went down to the machine shop. Pressure tested, surfaced, 4hrs port&polish, 22r valves machined to fit, and EGR tapped and plugged. Had a Comp Cam 260 installed and new Springs to match the .440 lift it had.


20R intake + LC adapter for 22r carb...

Some of the intake porting...

Had the engine completely installed and fired up multiple times with maybe 2 hours running time. Retorqued Headbolts/adjusted valve lash to Cam specs while warm. Then pulled it out of the garage and ALL hell broke loose
It had great oil pressure and then it gave like 5 knocks and BAM!!!


F#@$ ME! So the block is toast. What should I do guys????
Is it possible to bore a 20r block to 92mm and go from there? I'm hoping so, then ill just order up a kit from Engnbldr and Do it RIGHT. Any ideas would be helpful cause im about to blow a gasket.

drew303

If im not mistaken 22r blocks are taller than 20r blocks?

I'd source a new 22r shortblock or just a used engine and rebuild the bottom. Usually find em cheap =/

Sked

My junkyard here got rid of ALL yotas older then 84. Said nobody came for parts and just took up room. Nothing in any bargain finder, and I've only scene like 3 other 1st gens around town.
I Have an 22r 'Laser' block but I'm sure its 2mm shorter and it would mess up the cam timing big time. I'm talking about a pre-84 22r vs a 20r. Almost everything is interchangeable, same stroke but the 20r has a bore of 88.5mm vs the 92mm 22r.
Somebody has to know if it can be bored or not to the 92mm.

drew303

email Ted at engbldr .. he'll know for sure. Would a 85+ 22r cam sprocket fit on a 20r cam (or your cam)... ? In other words wouldnt a 85+ timing kit work with your shorter 22r block?

Sked

Well i emailed Ted about the 20R being bored to 92mm and he said it is possible. Sometimes when you bore it that much he said you can run into sand pockets or "bubbles". But I'm giving it a shot. Hopefully it will be done in 2 or so weeks.

slacker

iTrader: (1)

you'll have problems with boring the 20r .. from what I understand , cooling / hot spot issues as well .

I have 2 (pre-/85) 22r's but i'm in Penticton .. niether Pinedale nor North central have anything ?

i'd do some more looking before I wasted more money .

Sked

Decided to not bore the 20r that much, just for reliability reasons.
I really didnt want to drop down to 8.4:1 compression, so i bit
the bullet and ordered some 20r forged 90mm wiseco pistons with
9.9:1 compression. I think it should go well with the aluminum head and cam.
Any body else see a bump in performance with that high of comp? +im running 94octane