Probably a dumb question that it seems i may have the answer to but i'm putting my wires back on my Port 454 standard rotation (not sure if that means LH, RH, clockwise or counterclockwise I get so confused) but I'm confirming the firing order... it appears that both engines port and starboard have the same firing order stamped on the engine (13572468) but the distributor have different firing order per the manual which i attached - and it appears that the left motor (which i can only assume they would put the port motor on the left in this diagram) has a firing order on the distributor of 12756348.
My question? Does it matter where the 1 starts on the distributor? Or per my picture, should i start it at the top left of the cap?
Just confirming, for my port engine,
engine firing order 13572468 (counter clockwise from top left when looking at motor from above)
distributor firing order 12756348 (counter clockwise from top left?)
When the number one cylinder is at the compression stage (pull the #1 spark plug and try to bump the motor over to hear it) of the engine rotation you need to remove the distributor cap and see where the rotor is pointed. This will be the terminal on the distributor cap that the number one wire goes to. If you look at the firing order 1-8-4-3-6-5-7-2, the (1) is always first, the balance of the numbers are either read forward or backward, which is the same pattern depending on rotation direction of the distributor (confusing to put into writing).
Whitney, I couldn't remeber where #1 was on a HEI distributor but found this info online:
Is this photo from one of your 454s?
If so, that is an automotive distributor (vacuum advance not used in marine applications), not ignition proof and could have the wrong advance curve for a marine application.
@Warren Whitmore the vacuum advance is not used on this distributor, its capped, this distributor is on both engines and works fine, you aren't the first person to call it out, but i think it is actually fine. (ignore dipstick tube laying on motor).
@Steve Riley wow ok, more involved than i thought, but you are saying that i
remove #1 plug
bump motor until #1 clearly compresses
remove cap and not which point its pointing to
use that point as #1 then
for port engine standar rotation engine, use 184365721 clock wise on the cap
Whitney,
Unfortunately your photo shows the issue with using automotive distributors on a boat. Marine distributors have flame arresting screens on the vents to make them ignition proof for use in the engine room of a gasoline powered boat. That vent notch under the cap that I have circled on your distributor is fully open with no screening.
You may be better off replacing those old Accel HEIs with some new aftermarket distributors intended for marine use. Something reasonably priced like these: https://www.amazon.com/Team-Performance-Electronic-Distributor-Pleasurecraft/dp/B07MF4WZSR/ref=sr_1_1_sspa?crid=UOHJKEJ1BB12&dib=eyJ2IjoiMSJ9.VrtvhIejv5_fTd7WaCVey4clSBwSw1O-p0051zuStQFJsSesSizhrP-bCc7Y5u9eEYbo000wL-D67ZDndijCWgTgphWApu1OvuA0oAm_dNVNAlhJUaEY6bVQU72KGoi11U-d9dHt4y6JdZHEVZiCP2BIP5UkNkmkQeFuGY1P68pSkUjfSz65q2ic45YSqCRgdsxoV3i3YooGcUO2Dn2zFEJJwYJ_qCnGLXsIM6WEwmo.4rcP6zkg0F74C71oYud005q6UHDjQrzY8IVPrDaOVw0&dib_tag=se&keywords=gm%2Bv8%2Bhei%2Bmarine&qid=1747838187&sprefix=gm%2Bv8%2Bhei%2Bmarine%2Caps%2C94&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1
Whitney, your message to me is correct.
Apologies for being so negative on the non-marine distributors but I take this stuff seriously. In 1994 I witnessed a 1991 Carver 538 Montego explode at the fuel dock at the marina. Thankfully everyone aboard survived but I will never forget the experience.