Swap_File

As talked about in my previous post, I am working on swapping a Prelude B21A1 head onto an Accord A20 block.

The only other person I know of who preformed this swap had a machine shop make a shim to use the 28mm diameter shaft B21A1 crankshaft timing belt pulley with the A20’s 25mm crankshaft.

I am attempting to find a set of timing belt pulleys that will fit the A20 without machine work.

First, I tried to use two A20 camshaft timing belt pulleys on the B21A1 head, but they were too big and touched each other. Only 40 tooth gears or smaller fit.

This means I will have to use smaller camshaft timing belt pulleys, which means I will need to change my crankshaft timing belt pulley to match.

I have been measuring crankshafts at the local junkyards in an attempt to find a match, but it has been difficult to find all the engines on the list, and even more difficult to get at the crankshaft to take the measurement.

If anyone has an engine sitting apart (even if it is not on the list), could you please measure your crankshaft diameter (measured where the crankshaft timing belt pulley mounts) and post it? It would be very helpful. I will make sure to keep the list up to date with any information that is posted. It might help other people performing other swaps too.

Here is what I have found so far:

I limited my search to Hondas and Accuras that had adjustable cam gears available from AEM. (their site was easily searchable)

These are the different "Families" of camshaft cam gears (According to AEM):
(Pictures taken from various sources)

AEM PN 23-800
38 Teeth
Camshaft Gear Fits A20 - Yes (from Kabuki on PreludePower)
Crankshaft Gear Fits A20 - ?

-Might be the same as the 23-804
-Most companies sell the same gear for 23-800 and 23-804 applications

Found in:
Honda Civic 1988-95 D15/D16 SOHC
Honda del Sol 1993-95 D15/D16 SOHC
Honda CRX 1988-91 D15/D16 SOHC



AEM PN 23-801
42 Teeth
Camshaft Gear Fits A20 - Too big for DOHC, gears will touch. Unsure of shaft size.
Crankshaft Gear Fits A20 - Doesn't matter, the camshaft gear would be too big.

-Could possibly used for adjustable cam gear for the A20?
-See picture below of H22 belt with A20 gear

Found in:
Honda Prelude 1992-02 H22 DOHC




AEM PN 23-802
34 Teeth
Camshaft Gear Fits A20 - Yes
Crankshaft Gear Fits A20 - ?

Found in:
Acura Integra 1990-01 B17/B18 DOHC
Honda Prelude 1992-96 H23 DOHC
Honda Prelude 1988-91 B20/B21 DOHC (28mm Crankshaft)
Honda del Sol 1994-97 B16 DOHC
Honda Civic Si 1999-00 B16 DOHC
Honda CRV 1997-01 B20 DOHC




AEM PN 23-803
40 Teeth
Camshaft Gear Fits A20 - ?
Crankshaft Gear Fits A20 - ?

Found in:
Acura Integra 1986-89 D16A1 DOHC
Honda Prelude 1992-96 F22 SOHC
Acura CL 1997-98 F22/F23 SOHC
Honda Accord 1990-02 F22/F23 SOHC (F22 30mm Crankshaft)
Honda CRX 1985-87 EW3/EW4/D15 SOHC
Honda Civic 1985-87 EW3/EW4/D15 SOHC
Honda Odyssey 1995-98 4 Cyl.



AEM PN 23-804
38 Teeth
Camshaft Gear Fits A20 - ?
Crankshaft Gear Fits A20 - ?

-Might be the same as the 23-800
-Most companies sell the same gear for 23-804 and 23-800 applications.

Found in:
Honda del Sol 1996-97 D16 SOHC
Honda Civic 1996-00 D16 SOHC

AEM PN 23-805
38 Teeth
Camshaft Gear Fits A20 - No
Crankshaft Gear Fits A20 - ?

-If the Crankshaft gear would fit, it could maybe be used with 23-800

Found in:
Honda Civic 2001-03 D17 SOHC



I do not know if the crankshaft diameter is constant in each series of engines (Example, D16A and D16Z).

I believe the H22 and F23 crankshaft timing pulleys use the same shaft size, due to the G23 post here on Honda-Tech.

Swap_File

I know the above post is very long, so here is the short short version:

If you happen to be ripping apart your engine, please measure your crankshaft timing belt pulley shaft diameter. It can then be added to the above list. It will help with head swaps.