81 Ford van, mebie a 351w prior owner installed it.

Just got this thing going so it runs decently, and it has a problem I have noticed, first off, the carb would speed up and slow down while idling, not enough to die out, but enough to bother me. So while checking this out, I notice some paint on the Harmonic Balancer...it looks like a timing mark somebody had painted on it, but wait, this balancer is suppose to have a grooved mark already on it. While inspecting it, it is there, but appears to be on the other side, so this is telling me, somebody has installed the distributor 180 degrees off...and it still runs, but no pulling power going up hill.

 

You need to find Top Dead Centre on # 1 cylinder then remove the distribiutor and re-install it in the correct location give or take 1/2 a tooth..Also ensure firing order on the plug wires is correct...No big deal....

 

Not sure what an "mebie a 351w" has for timing marks, but have seen issue w/much newer Harmonic Balancer that ruined timing mark. The rubber ring inside harmonic balancer can grow old, dry out, shrink, go soft from oil leak, and/or get wrenched by stuck belt driven component. When this happens the timing mark gets moved relative to the crank pulley's core.

Good idea to do as blageurt says, but to 1st confirm if the timing mark is still accurate. If the timing mark on harmonic balancer is found to be correct, then open distributor & determine if rotor is "in the correct location". If it isn't, then may be time to "remove distributor and re-install in the correct location". After 30+ years someone may have distributor off a couple of teeth & the spark plug wires playing Musical Chairs.

 

I set a timing light on it, and it's moving when the motor is revved and isn't steady as it should be, the mebie 351w looks like a 351w...judging from other motors I have looked at and I have brought parts for this thing that I suppose could be a 351w...from the PO that had it before me, this is the second engine that's been in the Van...and he sold it because he couldn't get it to run right (lucky me didn't know that until after the sale)

I realize I'm going to have to get the timing right as it should be, and I know how to do it, but I didn't know that the engine could run "kinda" decent with the timing as far off as it is...am not even sure it's close to 8 or 10 degrees, but know that the Harmonic Balancer will have to be replaced if it's moving as much as I am seeing it move when the engine is advanced to higher rpm's. It starts up first time the starter is engaged and stays running (except for the low an high throttle while idling ..hunting for smoothness it seems...could be carb problem there)

No smoke, but pings going up inclines (could be distributor advance not working).

 

Pinging is a sign of to much ignition advance. Back off of the timing a few degrees and see what happens.

 

Sorry, don't "know" about that kind of "moving". Would think that "if it's moving as much as (you're) seeing" it would be extremely loose & should be EZ to diagnose.

The issue I described wrenches the harmonic balancer on its rubber sleeve, displacing the timing marks. However they tend to stay in the position they got twisted to & aren't seen "moving". It doesn't effect running, just puts timing marks off.

EZ way to check for this is to paint a stripe across the harmonic balancer rubber. Run it, then turn off & check if the core slipped inside pulley & stripe split.

 

i would start by verifying the timing marks. this can most easily be done by removing the #1 spark plug and turning the engine by hand, while using a probe such as a zip tie to feel the piston move up. find its absolute highest point, and it should match the timing mark.
i suspect that you and/or the PO may have been trying to time it from the wrong cylinder, causing the confusion, or else your mark has moved.

 

I have come to the conclusion that the distributor is at fault after reading others posts about the timing on the Harmonic Balancer moving while accelerating in the park position. Viewing the timing marks while using an timing light at their prescribed mark on the Balancer is a puzzle to me as to why go through all the trouble of making a mark on the Harmonic Balancer in the first place...if you're going to do a job right, then make sure the job isn't done wrong in the first place.

So now I'm going to buy another distributor and redo the mistake of the prior owner (PO) and hopefully, it'll be done correctly..using some of your good tips about setting up the timing.
On another note, the Sticker for this Engine was found on the top underside of the hood, after looking for it around the bay area to no thought as to look up to see it there.

The sticker says its suppose to be a 302w with an 8 degree timing.
I thought that the PO had stated that the engine was a 351w after they replaced it.

Is there a way to tell which engine it is by looking at the heads? I would perhaps need to know what type of engine this is to replace the Distributor, or would there be a difference, it does have a motorcraft 2bb carb on it.

 

i believe that both of those engines would have a 2bbl carb from the factory, and look pretty similar. IIRC you could tell the difference by looking at the distance between the water pump mounting vs the head, but thats just recollecting something i read around here, so don't take my word for it.

for the distributor swap, i believe the two engines would likely take the same one, you might look it up at your favorite parts store's website, such as oreillyauto.com - they have the best site of any stores local to me, and any of them can give you interchange info like that.

 

I am quite sure the the 302 and 351W are the same engine Family so there should be many similar parts...Like the 351M and 460...But Joshofalltrades has an excellent suggestion...

 

302 and 351w have different distributors. The 302 has a 1/4" shaft and the 351W has a 5/16" shaft thickness IIRC.

 

So..other than having to pull the distributor completely out, this is the only way of finding out which engine is actually in it? I had went to some sites that show what the picture of the carb looks like and it seems the use the same carb as well.

It seems that it doesn't have the carb that supposed to be on it as well, as I have a automatic and whats on it seems to be for a manual transmission (RockAuto)

I have done buisness with Orielly's here and they either always order the wrong parts for me or the part (s) fail almost to the warrenty so I been getting my parts from RockAuto or the local Napa.

I still haven't figured out how it will run like it is...

 

If memory serves me right, the way to tell the difference between the carbed 2barrel 302 and 351 is to measure the distance between the heads across the intake. One has a 9inch span, and the other an 11 inch span. Again, my memory may not be right on this, but I am pretty sure the 302 has the 9 inch span and the 351 an 11 inch span.

 

The 302 has a 1 inch shorter deck height. You can see this if you look at the distance of the timing cover/water pump from the top of the block surface that the cylinder heads sit on. The 351 will be 1 inch taller versus the 302.
There will be just a bit little space on a 302 and about 1 inch on the 351.

 

Thanks Rico and Jim...I'll check into it today since the weather will be better than 30 degrees...and will follow up on it.