V4 Valve timing question

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

rubyfocus

Richard Bennett
Joined
Jun 26, 2012
Messages
8
Reaction score
18
Hi folks- I'm in the midst of, I guess you could say, re-designing the wheel, but I'm trying to figure out the valve timing/firing order for a V4. I've spent a lot of time going over the geometrical aspects using a firing order of 1-3-4-2 (See attached PDF file for the layout), but something seems off to the point that I'm wondering if I'm looking at the whole thing wrong. Perhaps some of you out there who have successfully built a V4 could take a look at the attached file and see if I'm even close to figuring this thing out. Much appreciated and best regards!

Richard
 

Attachments

  • V4 crank-valve timing.pdf
    1.1 MB
What might be messing with you is the fact that a 90 degree V4 does not have a symmetrical firing pattern. Mine has a 90-45-90-135 degree pattern. There is also some trickery in the distributor. The electrode on the rotor is shaped like a hammer. 2 cylinders fire off the leading corner of the head
and 2 fire off the lagging edge. With a straight conductor the 4 outlets on the distributor cap cannot be equally spaced on the cap.

DSCN1625s.JPG
 

Latest posts

Back
Top