Ok I did the search thingy and could not get it to work:mad:
Also looked in faq and did not see it either:mad:

What I have is a 1980 20r with a good head but with a few busted rings . Just found a short block 22r 1986 .

What will I need to use the 20r head on the 22r motor ?
Will it work at all?
I can buy the short block 22r cheaper than rebuilding the 20r.
About 200 bucks cheaper:p

it will work, I just can't remeber all the details of the combo, give LC Enginerring a call, they can help you

never been able to get a straight answer on it. some people swear by it, others hate it

never seen it done by anybody i know, so i can't really tell

it would be nice to get a little bit of feed back from some of the guys out there that have made this mod in past .
I have spoken to a couple guys that say it boosts compression, but i wonder what is needed if anything to ensure the head will breath as well, are the valves a smaller size or the same size?

Originally posted by hard way
it would be nice to get a little bit of feed back from some of the guys out there that have made this mod in past .
I have spoken to a couple guys that say it boosts compression, but i wonder what is needed if anything to ensure the head will breath as well, are the valves a smaller size or the same size?

the valves are smaller on the 20r head, but with porting, some bowl work and bigger valves the 20r head can breath better than a stock 22r head

I swear by mine!

I used 22r valves(just slightly bigger).

The 20r heads have a much straiter shot through the intake passages, they boost compression, it is a hemispherical cumbustion chamber, and the head just bols on!

I ran a 20r head on my 22r years ago. It was ported/polished, but stock valves. Now, from what I have read, the head alone flows better untouched than a 22r head does, and you get alot of gains by not olny going bigger valves, but doing alot of bowl work. But the downside, you won't produce alot of low end torque, if any really. I wasn't impressed, and dumped that idea and built a good 22r head (agressive bowl work) and it was far better...

But presonally, just dump the POS 22r all together :D

You mean 'yota 4cyl's actually make torque?? C'mon you must be pullin my leg!:flipoff2:

Originally posted by TRDV
I swear by mine!

I used 22r valves(just slightly bigger).

The 20r heads have a much straiter shot through the intake passages, they boost compression, it is a hemispherical cumbustion chamber, and the head just bols on!

The 20r head is a open chamber head like the pre 85 22rs so swaping the head onto a 85and up 22r short block does not boots compresion, unless you have the head shaved (20r head 80-81cc chamber 81-84 22r head 82-83cc chamber 85-95 22r head 58cc chamber).The main reason for swaping to 20r head on a 22r block is becouse the port configuration alows for better flow with there round intake ports (22r heads have square intake ports).

right,
Learn something new everyday:D

Like Blacktoy said, LC Engineering has info on that, this is from their website:

It is possible to run a 20R Head on an 85-95 laser block. In order to keep the cam and crank centerline consistent with an 85-95 head, you must mill the 20R head to a measurement of 3.130 (measured from the bottom of the front cam journal to the deck of the head). Remember to re-machine the oil passage back into the deck surface of the 20R head after milling to retain oil passage to the top of the motor.

http://www.lcengineering.com/home.htm

take a look at their "Tech Notes", good reading

You can also go to the "Tech Info" on this site for the 20R and 22R.

http://www.toysport.com/index.htm

This combination will not work with out modification.
The 1980 20R is a 98 row timing chain motor [75-84], and the 86' is a 96 row timing chain short block [85-95].
The 20R head must be surfaced 0.147" [as i recall] this will be the thickness of the 85-95' head. Then the factory chain will fit.

I have done many of these conversions, but due to the smaller combustion chamber, only the factory cam can be used unless you flycut the pistons for valve clearance.
You must also use the 85-95' shorter head bolts.

I have been running this combination in my 1980 crawler truck for years now. It increased my compression ratio from 8.4:1 to 10:1 and was quite impressive when i built it.
At first i installed the larger 22R valves in the 20R head but was beat out by a motor using the factory valves.
I am at present running a 90' "lazer" block with a BMW double row timing chain, turbo oil pump and cooler, and a ported 20R head with factory valves and a 86' turbo camshaft.

Marlin

Marlin You stated that you must flycut the pistons, Are you refering to the 85 up 22r. I got a 1983 22r with a 1979 20r head popup pistons and way bigger then stock cam, I checked the clearence to the pistons/valves on this motor and there was alot of room. Yes you are right the stock valves will build more torque, I was going to go with bigger valves but i would have to give up any chance of low end torque. I also went with dual coil valve springs, to up the valve seat preasure wich also will bring back some torque. This motor turns it on right around 1500rpm and falls off about 4500rpm. This combo works killer on my motor. :D

man i cant beleive it finally some answers i have been searching this combo for 4 months now trying to get some info on the combo from what ya'll say i should be fine (80-20r head 83 22r block ) i even went ahead and got a 92 block just incase the 83 wouldnt work .the answers i got in the past were that it wouldnt work unless i did some major machining to the gain is not as good as just going with a 22r complete setup

oh and :flipoff2:

Here's what I was running:

'80 20R Head. Ported & polished intake and intake runners, just ported exhaust runners. Head cut to an overall height 3.797" Duel springs, stock 20R valves.

'86 Laser block 93mm bore. Stock crank & rods, 9.4:1 compression pistons. (No flycuts) balanced and blueprinted rotating assembly
TRD Stage 3 cam
Weber 32/36
Longtube Header
'86 Timing chain set with DOA guides
MSD 6A

Ran super stong for a 4 popper!!!!!!

Chad sounds like a winning combo. But how's that weber working. I havent seen to many that work good off road..

The Weber worked great!!! No problems at all...other then almost straight up and down.

I ended up selling the whole deal because I'm putting intalling a Vortec 4.3 in.

seems like there's few people who like webers, because i'm happy with mine. works great offroad

i think i'm just going to combine the two 20Rs i have and make one good engine. i have a spare sitting in the back yard that definitely needs to be taken to a machine shop and checked out...the engine's probably been sitting 20 years! i figure i could at least use the head and intake off it and maybe the block i have in my truck...

how would they compare to a stock 2bbl asain from a 22r the donor engine came with a almost new carb but i also have a weber 32/36 either way a will need to get a adapter plate to use it on the 20r or go offy intake

This link might be helpfull

http://www.speedtoys.com/~oldmage/20RE-1.htm

Luc