[Longrex]

I have a 91dx with the D15B2 engine. Do I set the valve clearance according to the (Chilton's, Haynes etc.) common recommendations? I suspect that most of the clearances are for D16 engines. Those books don't seem to differentiate. I'm getting in the mood to adjust. I have the Haynes (on CDrom) for CRX Si, but certainly NOT for the Dx.

If D15B2 engines share the same head as D16 engines, how can the valve settings be the same if the cams are different? Reason for this question is that I also have a 89si with a D15B2 in it. I replaced the head with a professionally rebuilt head, and it may have a D16A6 cam in it.

I did a "quick" search, but found no result.

 

[jfrolang]

According to my Helms factory service manual (1991), the dx and Si have the same clearances.

Intake: 0.17 - 0.22 mm (0.007 - 0.009 in.)
Exhaust: 0.22 - 0.27 mm (0.009 - 0.011 in.)

 

[hcrx333]

the d15 and d16 do not share the same head.

 

[Longrex]

>According to my Helms factory service manual (1991), the dx and Si have the same clearances.

>the d15 and d16 do not share the same head.

Uh, oh... I thought Si's came stock with a d16, dx (automatic) stock with d15? I may be getting a little confused. I suspect that my 89Si has had a non-documented engine replacement before I bought it.

jfrolang, thanks. I'll tune my Dx to those specs, as I did last time.

 

[rex2nr]

The DX and Si share the same head casting and valve train, but the cams are different. The HF has a similar head casting, but different valve train and cam. HF heads are only 8 valve, and they have puny ports.

 

[jfrolang]

Uh, oh... I thought Si's came stock with a d16, dx (automatic) stock with d15? I may be getting a little confused. I suspect that my 89Si has had a non-documented engine replacement before I bought it.

jfrolang, thanks. I'll tune my Dx to those specs, as I did last time.

The Si did come stock with a D16A6, and the dx had a D15B2 regardless of transmission choice. As rex2nr pointed out, the heads are identical except for the cam.

What engine is in your 89 Si?

 

[Longrex]

89 Si = D15B2, printed on the block.

Different head/or cam. Runs great. Timed to standard "Helms" tolerances.

I know it's wrong. But it runs good (Si).

Right now I want the DX auto. to run better. So: tune up time.

 

[Longrex]

>The DX and Si share the same head casting and valve train, but the cams are different.

Does this mean the valves are to be set differently, because of the cam?

 

[jfrolang]

The clearances are the same.

 

[luober]

if i'm not mistaken, the correct valve clearences are noted on the emissions sticker on the engine side of the hood, if it is still readable.

 

[ludesrv]

if i'm not mistaken, the correct valve clearences are noted on the emissions sticker on the engine side of the hood, if it is still readable.

Just like the spark plug part number is listed on the cam gear cover.

 

[slowsway]

Late post, but does this mean that an aftermarket non-vtec cam is practically universal?

 

[Mista Bone]

Late post, but does this mean that an aftermarket non-vtec cam is practically universal?

except for that 1/2 tooth cam timing issue that I noted 13 years ago.

 

[nylumiro24]

go with what the manual says...

According to my Helms factory service manual (1991), the dx and Si have the same clearances.

Intake: 0.17 - 0.22 mm (0.007 - 0.009 in.)
Exhaust: 0.22 - 0.27 mm (0.009 - 0.011 in.)