I am finally putting together my carbureted all motor d16--I am asking this question here--because I usually get more informed responses in the FI forum. I've got the factory main bearing oil clearances--but they vary--for 1 and 5 its 0.0010-0.0014, 2 and 4 its 0.0010-0.0017, and 3 its 0.0012-0.0019. Could I just go in the middle and do about 0.0015 for all the main bearings, or should I follow this to the tee? This is for a 90-91 si motor, for the 89 on 1 through 5 it was 0.0010-0.0014 I believe. Isn't 0.0015" a good all around main bearing clearance for small honda motors? Also, the main bearing journals are numbered in the same order as the cylinders, correct? In other words, #1 is closest to the timing belt, and #5 is closest to the flywheel--is that correct? Any response is appreciated, thanks.

 

Piston-to-Cylinder Wall Clearance
Bore Diameter: 75.50mm, Naturally Aspirated: 0.0021" , Forced Induction: 0.0022"


Piston-to-Cylinder Head Clearance
With Eagle Steel Connecting Rods: 0.035" Minimum
With Factory Connecting Rods: 0.045" Minimum

Valve-to-Piston Clearance
Intake Valves: 0.045" Minimum
Exhaust Valves: 0.060" Minimum

also for rod and crank bearing clearances .0015 is a good number for both. Yes #1 is closest to timing belt. hope i answered your ?


Modified by ZC1.8crx at 1:42 AM 9/5/2005


Modified by ZC1.8crx at 4:39 PM 9/5/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ZC1.8crx &raquo;</TD></TR><TR><TD CLASS="quote"> Piston-to-Cylinder Wall Clearance
Bore Diameter: 75.50mm, Naturally Aspirated: 0.0021" , Forced Induction: 0.011" ?</TD></TR></TABLE>

.011"??????? is that a typo?

 

correct on your numbering.
as long as your clearances wind up within the proper range, you will be fine.
.0015 clearance will work great for you.

 

yes. it was changed, it should have been .0022"


Modified by ZC1.8crx at 4:40 PM 9/5/2005

 

Thanks for all the responses guys--I really appreciate it. The piston to wall clearances you gave though--is that for a factory cast piston? I am using a JE piston--I assume the piston to wall clearance should be increased for a forged piston, correct? Also, I don't know if it matters, but its a 79mm bore d16a6......

 

one question now that u have this topic on clearance

on piston to wall clearance does it have to be more for a fi set than a n/a set up . why is that ???

 

do to heat and pressure. In the engine the heat in the chamber is different so for heat in
a NA is less so the tolerance can be less or tight, for FI the heat on the piston will cause it to to grow at a faster rate than the cylinder walls.

This is for forged pistons(endyn, wiseco) BUT Remember these are good starting points and you should always go by manufacturer recomended specs. I hope this answered your question.

 

also srp not je makes your pistons even though there the same company. Srp make there piston from 4032 alloy which has a high silicon content i believe it's 15% so because of this you can go with a tighter tolerence. for 79 mm you could probably go with .0024-.0025 piston to wall spec for NA.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by d16dcoe45 &raquo;</TD></TR><TR><TD CLASS="quote"> Also, I don't know if it matters, but its a 79mm bore d16a6......</TD></TR></TABLE>Can you please post a pix or send a pix to me by e-mail. I have never seen a D16 at 79mm. It must be getting thin between the cylinders.

 

bump, goog info.