4agze lower on 4age uper ?'s

[insansk8er90]

well might be bying 4agze block pistons and rods and i have a few questions?
1. the upper from the 4age work on the z block? alt. mounts exc......
2. z rods on a 4age crank....will it work?
3. can i run the 8.1 comp. until i get the money to by supercharger... or could i get forged 4age 9.1 compression pistons and then turbo it when the time comes...
4. are crank bearing journals th same size?
5. and anything else you guys could think of

[mr2tim]

Mr. Willis is our Club sponsor and works for Toyota. He may be able to confirm the following specifications taken from the 89 mr2 Serivce Manual for USA and Canada
(Aaron may even drive a Mark1 like us, but I'm not sure.)

Info from the BGB=PAGES A-(3-5.)--our Toyota Bible---

1 (all heads are apparently the same)-service manual only gives 1 spec for all the heads. (Para 2, Page A-3)
A.) Only 1 camshaft specification is given (apparently all cams are the same for all the models.) (Para 2, Page A-4)

2. Diameters of the piston sleeve itself is only listed as 81.23mm on all blocks.(All blocks are of the same bore hole size) (Para 3, Page A-4)

3. Ring size differs between S/C and N/A, with the S/C being tighter.
(Pressurized engines need tighter sealing?)

4. Page A-5 indicates only one specification for the connecting rods and bearings.(con rods and piston pins are the same)(Para 4, Page A-4)

5.Same as above for the crankshafts (no difference in n/a and s/c) (Para 2, Page A-5)

I hope this can address the parts swap you are interested in performing.

When in Doubt, follow the Specs!

Tim Nusbaum (mr2tim)
Former National Technical Inspector
South Florida Region SCCA

[DarylP]

Originally Posted by insansk8er90

well might be bying 4agze block pistons and rods and i have a few questions?
1. the upper from the 4age work on the z block? alt. mounts
2. z rods on a 4age crank....will it work?
3. can i run the 8.1 comp. until i get the money to by supercharger... or could i get forged 4age 9.1 compression pistons and then turbo it when the time comes...
4. are crank bearing journals th same size?
5. and anything else you guys could think of

Some answers:
1: Yes any of the 4age heads will work on the z block other than needing 20v pistons with that head.

2: Depends on the crank that is in you 4ag block some are small journaled some are the larger sized journals that come in the z block. You would have to mic the rod throughs and see if there 20mm.

3:You could run with 8.1 but it will be alittle doggie and get low mileage due to the lower cylinder pressures

4:Like I said the rod journals on the z and some of the newer 4ag's are the larger journaled cranks need to mic it.

5: money?

[insansk8er90]

aaron does drive an mk1....or at last will when i get money to buy your stuff