Small Block Forum - Timing issue

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Timing issue

Printed From: The Ford Torino Page
Category: Powertrain Specific Forum
Forum Name: Small Block Forum
Forum Description: 221, 255, 260, 302 and 351W engines
URL: https://forum.grantorinosport.org/forum_posts.asp?TID=20232
Printed Date: 26-March-2026 at 3:21PM
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com

Topic: Timing issue

Posted By: StarskyHutch75
Subject: Timing issue
Date Posted: 19-June-2022 at 4:11PM

I have a 408w in my 75 and I just installed a ready to run msd distributor. The engine builder said timing should be set at 12° at 1000rpm and full advance should be 36° at 3000rpm. I changed the springs and bushing out using the msd instructions and charts. My bushing and springs would give me 35° at 3000rpm when set at 12° at 1k. Is the 1000rpm what my curb idle should be set at? It seems kinda high to me. I installed the msd to replace a junky amazon hei distributor but the car ran fine before msd install. Now it runs rough and isn't drivable in its current state. Should I just replace the msd back to the way it came out of the box? I forgot to mention I'm running vacuum advance but I've made sure to cap it off when setting timing. Any help is greatly appreciated as I miss driving my car

Replies:

Posted By: 72 RS 351
Date Posted: 20-June-2022 at 1:29AM

The initial timing you can play with and vary to see how it helps the running, at idle and transition etc. It's good to have a baseline recommendation from the engine builder. I'm not going to criticize him at all for that. He may have built other engines like yours that he learned run very well at the 36* total, etc. But he may also be off some if he hasn't built one just like yours, and is guessing based on other engine builds.

So it hopefully it's just some adjustment you need to do with the timing, or the fuel. What carb do you have on it, and is it made or set up for that 408 combination?

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Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000 rpm 351 stroker
73 Ranchero GT 351C-4V &4R70W for sale later.
92 Lincoln Mark VII SE GTC, OBDII 347/4R70W

Posted By: Big Bird
Date Posted: 20-June-2022 at 6:31AM

At 1000 RPM, the distributor will be getting some advance from the vacuum, and likely the mechanical advance as well. The builder is giving you good "initial recommendations" but the "best results" final numbers will depend on your distributor, idle, carb, intake, etc.

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"What we do in full frontal view, is more honest than your cleaned-up mind."
Randy
1979 T-Bird
2005 F-150 STX RCSB 4.6, 3.55 LSD
How the Heck does a REGULAR CAB SHORTBED weigh over 5200 pounds?

Posted By: Rockatansky
Date Posted: 22-June-2022 at 11:15AM

the rest of the world sets base timing at normal idle in park with the vacuum disconnected and plugged. 12* is a good starting point but you might find that any combination of bushings and springs might need a slight tweak to achieve a base timing that gives your desired 'total timing. total timing does not include any vacuum advance, just what the base setting and what the internal mechanical advance mechanism provides at 'X' rpm. so you might find 13* base and your bushing gives 36* total for example.

the question is "why the heck does it not run well with the MSD distributor?

back to basics, vacuum leak? have you done anything with or changed the carb?

hopefully your cam & lifters are not failed

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72 GT Ute