I think this may be the timing set we are all talking about. Here is the link....
COMP Cams 3221 - COMP Cams High Energy Timing Sets

 

dont get me wrong, cause im not a master mechanic, but.....
isnt the cam the problem and not the gears?

 

I went through this a couple years back with my 351m. I finally bought a timming set from summit that could be set 4deg advanced ,straightup or retarded 4deg and set it for as advanced as it would go. it made a difference but as the previous set was pretty worn it was hard to tell whether it was from advancing the timming from factory or whether it was from just replacing the worn one.

 

I went with a comp cams doublerow timingchain and have -4,0,+4. I set to 0 (straight up) and had no problem for instalation

 

I had the same question when I rebuilt my 400. I used a Crane Cams gearset and chain, (along with the cam and all the other valvetrain parts) and I called the Crane Tech line during my installation because I found that the piston went past TDC, and was down in the cylinder bore .040", when the timing marks on the crank gear and cam gear were exactly lined up. I thought lined up marks on the gears should be with the #1 piston at TDC, or within a few thousandts of TDC. I was convinced that I had screwed up the cam to crank gear alignment by one tooth, but it turns out I didn't. To answer your question, two different tech reps said that the Crane gear sets removed the six degrees (if I remember correctly) of retarded valve timing that is built into the factory Ford gears.

However, the performance articles I've read say you're taking a risk that the valve timing can be off a significant amount if you don't check cam timing, because in about one out of a few hundred engines, the keyway in the crank can be cut "wrong", or have other problems that will result in valve timing far enough advanced or retarded from straight up (outside of about four degrees) that it will deleteriously affect engine performance.
I did my engine in the car, and was under time constraints to get it done, so I didn't check my cam timing. I'll never know If I'm where I want to be or not. I'd check it if I were you.

 

RCrawler. what year engine did that original set come out of?

there is a visable difference between the early and late factory crank sprockets, you can see it in the relationship of the keyway to the nearest tooth. on one the tooth is centered on the key, the other is visibly offset. i just don't recall which is which...

cams are not all the same either, the Bubba info shows the valve event timing is different for different cams/years... http://tinyurl.com/d7q68y

 

stupid question but what do you mean when you say "straight up" for the cam?

 

slang definition is that the cam is installed with the timing set at the 0 position, not advanced and not retarded.

technical definition is that the cam is installed to the manufacturers intake lobe centerline spec. this may require using advance or retard key slots, keys and/or degree bushings to achieve the manufacturers intake lobe centerline spec.

 

It is a '79 400.

Calling around to several local parts houses and some online parts sources, I found that the '71 and the '79 timing sets always carried the same part number. I found another source that said that the truck engines went to straight up timing in '78. I don't know.

Jason

 

It is a '79.

I came across a site that claimed the '78 and newer trucks went back to straight up timing.


Jason