47-59 VIN & Block Numbers

[Sammy4358]

Can anyone help me figure these numbers stamped on the block on the passenger side just under the alternator. I am trying to figure out the size of motor and what it came in. The first set is the 3/16" lettering ( F1031CEM ) and the second set is 1/8" lettering ( 18L532064 )

I am trying to do repairs and don't know for sure what motor it is.

[mr48chev]

OK V8 What year is the truck supposed to be?

Using both that suffix code and the casting number of the block you can usually nail it down right.

I didn't study this line for line to see how accurate it is but it is usable info.
https://www.speedwaymotors.com/the-t...-numbers/28660

The lime book that they refer to is this one https://www.ncrs.org/ok/LIME_BOOK_2018.pdf

CEM shows to be an 80 305 that came with a 4 barrel and turbo 350

Or what year was the engine sold to you as and what is the casting number on the drivers rear

[Sammy4358]

It's a 1959 apache and probably had a 265 six with 3 on the tree. It now has this v8 with a turbo 350 automatic. I think it it a 305 from a Camaro or Omega
and it will not idle very good and I had a shop look at it and he said the harmonic balancer is not the correct one. He could not set the timing, the number one was not near the timing mark.
So this is why I need to know for sure what this motor is out of so I can get the correct part.

[mr48chev]

I'm thinking that the correct timing mark location for an 80 305 is going to be straight up at 12 Oclock.. There is probably a tube next to the mark on the cover for a probe from a scope. A lot of 70's and 80's small blocks came with the timing mark there because you couldn't get to it with a timing light from the side. If it has an aftermarket timing tab on it you can bet that is what the issue is.

If it still has the long pump on it look straight down behind the water pump at the timing cover and you should be able to see that tab and the tube if it still has the correct cover.

I had a hell of a time with my 71 when I put the 350 out of the 79 Elcamino that my son totaled in it and put the 71 short pump on it. The same exact issues you are having.

I'd pull number 1 plug and bring it up on compression and see if the mark was right close to 12 O'Clock.

[mr48chev]

I'm saving the link to the "Lime book" when you scroll back up the page to see what "CA" means it is Camaro. Meaning that the engine came in an 80 Camaro with a turbo 350 and is a 4 barrel 305. Specs for that engine should get you in the ballpark.

[Rickysnickers]

Sounds like there might be an issue with the balancer. If it's old, it could have rotated enough on the rubber ring that it would cause any timing reading to be way off.

[mr48chev]

Originally Posted by Rickysnickers

Sounds like there might be an issue with the balancer. If it's old, it could have rotated enough on the rubber ring that it would cause any timing reading to be way off.

There is always that chance on that style of balancer that is two pieces with the rubber and nothing else between them. Just as there is the chance that the outer ring will come of on it's own. I've seen that and the carnage involved a couple of times. I also had a guy bring me the two parts and the rubber sleeve years ago after he had used one of those three arm gear pullers to pull the damper off and turned it into a real two part damper. He was wanting to know if we could put it back together.


Back to the subject at hand, Sammy 4358 is most likely going to have to find TDC on number one using traditonal methods and then see where the mark on the damper is and if it is at 12 O'Clock or where ever and go from there.

[Sammy4358]

OK, I took out the distributor, plugs and wire. Got a TDC whistle and located TDC on the number one cylinder on the compression stroke. The old timing mark was about 1/2" to the left of the timing flange. Put new mark on the balancer, set it at 10degree put back the distributor, plugs and wire. Started the motor and was only hitting on maybe three cylinders, had to turn the distributor counter clockwise about two inches to make it run somewhat smoothly. Put on the timing light and the new mark was at about 12:00, way away from my TDC location. It still runs rough like it has an oversized cam and when I put it in gear at idle she tries to stall. Could the motor run if the timing chain is one tooth off?I don't know if the problem is in the timing or Carburator. I have a Holly 4 barrel but the intake manifold has just two rectangle intake holes and the carb. is setting on top of a spacer with the 4 holes.

[mr48chev]

It could run if the distributor was a tooth off.

Pop the cap off and put a socket on the bolt that holds the damper and pulleys on the crank and turn the crank counter clockwise and then clockwise and see how far the crank moves before the rotor turns. If the chain is sloppy or the plastic (if still original) gear is bad it may either be off timing or have jumped time.

[Sammy4358]

I replaced the points with an electronic ignition. So I will take the distributor cap off and rotate the engine counter clockwise. How much should I be able to rotate before the rotor moves?

[geezer#99]

A whistle only gets tdc in the general area of true tdc. You could be Like about 20 degrees off.
You need a piston stop to be accurate.
One like this.


https://www.summitracing.com/parts/s...SABEgLY_vD_BwE

[Sammy4358]

I used the whistle to find the compression stroke and used a screwdriver to find TDC. I could move the pistons up and down with the wrench and I set TDC at the halfway point from when the piston reached the top of the stroke and started to go down, the wrench would only move a few inches. The origional timing mark could be good, it was only 1/2" to the left of the timing flange. I set the distributor with the number 1 plug at 5:00, I don't know why I had to rotate the distributor counter clockwise at least 2" to get it to run. and the timing mark is also about 2" to the left of the timing flange.

[geezer#99]

Yup!
The old calibrated screwdriver trick.
Always good for at least 20 degrees out of wack.

[Sammy4358]

I went ahead and changed the timing chain and gears reset the timing lined up the circles on the timing gears. Took the driver side valve cover off and watched the valves open & close to find the compression stroke. when the number one was TDC on the compression stroke the circles on the crank and cam gear was at 12:00. I put the distributor back in with the number one wire at 5:00. When I cranked it up I had the very same problem, I was able to advance the rotor to the number one plug to about3:30 and the timing mark is behind the water pump. The motor runs the best with the mark at about 11:30. There is still a good rumble out the exhaust and I only get about 14 lbs of vacuum. My vacuum meter says delayed timing?????

[mr48chev]

We have been going through the exact same thing with a guy who goes by WP38 on the Hamb. But he put a chrome timing cover and tab on his 305 and that put the mark in the wrong place.

[dsraven]

lots of guys do this method of adjusting timing with a vacuum gauge. keep in mind that not all engines have a distributor that turns clockwise to advance the timing.
https://automotivemileposts.com/garage/v2n8.html
you should mark your vibration damper hub and ring so you can always know if the hub is rotating inside the ring.
it sounds like you should possibly do a complete check-over on the engine. compression dry and wet, cylinder leakdown test, cam lift check to ensure there isn't a flat lobe (common on the late 70's and early '80's 305 engines. it will make the engine seem to be out of time, popping, valve train clacking and misfiring.https://itstillruns.com/tell-bad-lob...t-6293277.html), valve adjustment etc. then you know what you have to work with.

[Sammy4358]

Someone along the line did the same thing, chrome timing cover. I'll just set the timing at what the motor want's
Thanks

[Sammy4358]

I forgot to mention in the post I replaced the harmonic balancer also. Great info on the vacuum timing, that will help a lot
Thanks

[mr48chev]

If you bought a damper for an 80 Camaro with a 305 the mark is going to be at 12 Oclock/.

Looking at this iisting or Chevy small block dampers on Summit's catalog. There are a number of spots that the timing mark can be at,