H Model Restoration

[h67st]

I finally got the alternator bracket straightened out, installed the radiator, hooked up temporary fuel and air start tank, etc. One question; the fan belts vibrate between the WP and crank pretty heavily at certain RPMs, even though I have them pretty tight. Will worn sheaves cause them to vibrate? Any other ideas? I don't want to throw the belts.

 

[h67st]

One other question--I have to pour fuel in the inlet line to get the primer pump to work, even then a lot of pumping. It also loses prime, even though I put all new fittings, fuel lines, filter, etc. Will a bad primer pump cause it to lose prime? I had the injection pump rebuilt but I don't know if they checked out the primer and check valves.

[terry]

1 hour ago, h67st said:

One other question--I have to pour fuel in the inlet line to get the primer pump to work, even then a lot of pumping. It also loses prime, even though I put all new fittings, fuel lines, filter, etc. Will a bad primer pump cause it to lose prime? I had the injection pump rebuilt but I don't know if they checked out the primer and check valves.

definitley check out the two plastic check valves first.   terry

[Vladislav]

Yes, as said above. If a valve's leaky it would allow the fuel to run back into the tank and also cause loose of pumping allowing the fuel escape that same way instead of traveling to the injection pump.

The matter of the belts jumping could be pulleys out of center. Or unevenly worn grooves. I never meet such issue just figuring. Maybe uneven hardness of rubber in the belts due to drying out during storage?

[Vladislav]

Congrats on the first start!

Didn't you bother the injection lines so they kept fuel in the injectors? Looked like pretty easy start for newly assembled fuel system.

[mowerman]

I also loose prime but I haven’t done anything to the lines (very ) old plus the primer leaks that engine sounds great no Smoke nice work bud thanks for sharing With us good luck with the prime issue . Bob

[doubleclutchinweasel]

Old belts can definitely cause "flutter".  So can off-center, bent or unevenly-worn pulleys (sheaves).

[Freightrain]

Yup, pull the two plugs on the primer and make sure the plastic check valves and springs are okay and the seats are clean.  My 237 was gunked up, once cleaned out work fine.

As for belts?  Mine flop around too but not sure compared to yours.  How is the crank pulley?  Run true?  Watch each pulley and see how they run.

Love the air start.  Like mine you can't let go of the valve fast enough because it starts so easy.

[h67st]

On 3/31/2021 at 3:49 PM, Vladislav said:

Congrats on the first start!

Didn't you bother the injection lines so they kept fuel in the injectors? Looked like pretty easy start for newly assembled fuel system.

I primed it before starting...had to fill the fuel filter and pour fuel in the inlet line before the primer would pick it up. I'll have to check out the valves.

 

9 hours ago, doubleclutchinweasel said:

Old belts can definitely cause "flutter".  So can off-center, bent or unevenly-worn pulleys (sheaves).

I put new belts on but the WP pulley is pretty worn...that may be the issue.

[h67st]

9 hours ago, mowerman said:

I also loose prime but I haven’t done anything to the lines (very ) old plus the primer leaks that engine sounds great no Smoke nice work bud thanks for sharing With us good luck with the prime issue . Bob

It actually does smoke but I had some round duct clamped to the exhaust pipe, carrying the smoke outside.

[mowerman]

OK gotcha I was thinking it should’ve been smoking a little bit first start thanks for the response..... bob

[mrsmackpaul]

I typed out a reply must of not pushed submit

 

Anyway I'll have another go

 

Fantastic effort so far

Your vee belts need to be a matched pair, lots of manufacturers say they are matched belts but this isnt exactly true

Say for example yiu have B 85 belts and buy three belts that are meant to be matched, if you look closely at the belts there is another number made up of may 5 or 6 numbers in smaller writing, this number is the matched number and the closer these numbers are to matching the closer the belts are to be matched

 

This isnt some made up B.S. this is fair dinkum and when they numbers are really close the belts (providing the pulleys are in good nick) will run smooth as silk

 

So check the belts out, most spare parts people dont know this, a older spare parts gentlemen showed me this many years ago and it still proves correct today

 

Paul  

[Rob]

8 hours ago, mrsmackpaul said:

I typed out a reply must of not pushed submit

 

Anyway I'll have another go

 

Fantastic effort so far

Your vee belts need to be a matched pair, lots of manufacturers say they are matched belts but this isnt exactly true

Say for example yiu have B 85 belts and buy three belts that are meant to be matched, if you look closely at the belts there is another number made up of may 5 or 6 numbers in smaller writing, this number is the matched number and the closer these numbers are to matching the closer the belts are to be matched

 

This isnt some made up B.S. this is fair dinkum and when they numbers are really close the belts (providing the pulleys are in good nick) will run smooth as silk

 

So check the belts out, most spare parts people dont know this, a older spare parts gentlemen showed me this many years ago and it still proves correct today

 

Paul  

A set of calipers easily confirms the measurements between belts. Best not mix brands on the same sheaves, (pulleys, drives, etc.) and stay as close to same dimensions as possible. 

There used to be available a set of "master" blocks for checking wear in the sheaves of "vee" belt drives also but I've not seen any in years. These you would slip into the groove and use a round wire feeler gauge to check for wear in the angled section of the drive.

Many times new belts installed onto worn out drives shorten the life of the belts considerably.

[mrsmackpaul]

If you just sit the same belt in each groove and check how much it protrudes from the groove I think would give a good indication if the pulley is badly worn I would of thought, totall open to correction 

 

Paul

[h67st]

1 hour ago, mrsmackpaul said:

If you just sit the same belt in each groove and check how much it protrudes from the groove I think would give a good indication if the pulley is badly worn I would of thought, totall open to correction

Paul

The belts sit down into the sheaves on the WP pulley, the pulley is definitely worn. Anybody know a part number or where I can get a new pulley? I will definitely try to get a matched pair of belts--I've seen those in the past.

[Rob]

These folks have helped me in the past with automotive applications. I don't know about heavy trucks:

https://marchperformance.com/tech-support

[Vladislav]

On 4/4/2021 at 4:35 AM, h67st said:

The belts sit down into the sheaves on the WP pulley, the pulley is definitely worn. Anybody know a part number or where I can get a new pulley? I will definitely try to get a matched pair of belts--I've seen those in the past.

Couldn't the pulley being put into good shape using lathe? They're cast iron parts in many cases and may have enough of meat to cut off.

[mrsmackpaul]

11 minutes ago, Vladislav said:

Couldn't the pulley being put into good shape using lathe? They're cast iron parts in many cases and may have enough of meat to cut off.

Thats probably what I would do 

[Vladislav]

12 minutes ago, mrsmackpaul said:

Thats probably what I would do 

Yup. And dial checking its center when installing for the cut would allow the belt grooves exactly where they should be.

[Rob]

The largest problem when remachining vee belt drives is the depth of the the belt riding in the pulley, (sheave) increases where the belt rides. This exacerbates the aforementioned problem as there is little power or torque absorbtion if the belt is bottomed in the groove which will happen if the angled sides are trued to linearity in many cases.

[h67st]

I looked at my parts trucks, one of them had a pulley with a lot less wear. The belts sit up in the top of the grooves and vibrate less now. The part number on it is 302GC2187A; they are still available from PAI.

[doubleclutchinweasel]

I have been making commercially available, industrial V-belt pulleys (among other things!) for a living for the last 39 years!  So, this one hits close to home.

"Matched" belts are cut from the same belt of raw material.  So, the individual belts are as close to identical as possible.  Each raw belt will be slightly different.  So, 2 belts of the same number cut from different raw material could be different.  Matched sets are ESSENTIAL in an application like this.

There are standard V-belt groove dimensions defined by the MPTA (Mechanical Power Transmission Association).  I can probably sanitize a drawing and share some of the information, if anybody needs it.  Just need to know the belt type (A, B, 5V, etc.) and the outside diameter (OD) of the pulley.  The groove angle changes as the pulley gets larger or smaller.

To measure the effective Pitch Diameter (or PD) of the belt, we simply measure over a pair of dowel pins.  The pin diameter changes depending on the groove type.

Lots of manufacturers of pulleys (we actually call them "sheaves") use a form tool to generate the V-form of the pulley groove.  But, I have found that this gives bad angles, chatter in the grooves, bad flank finish, and deformation of the web between the grooves...which can throw off the PD of one or more of the grooves.  So, for the last 35 years or so, I have been profiling the grooves with a 35-degree insert.  This gives far better groove integrity than can be achieved with a form tool.

Let me know if I can help with anything on this.

[Vladislav]

1 hour ago, doubleclutchinweasel said:

I have been making commercially available, industrial V-belt pulleys (among other things!) for a living for the last 39 years!  So, this one hits close to home.

"Matched" belts are cut from the same belt of raw material.  So, the individual belts are as close to identical as possible.  Each raw belt will be slightly different.  So, 2 belts of the same number cut from different raw material could be different.  Matched sets are ESSENTIAL in an application like this.

There are standard V-belt groove dimensions defined by the MPTA (Mechanical Power Transmission Association).  I can probably sanitize a drawing and share some of the information, if anybody needs it.  Just need to know the belt type (A, B, 5V, etc.) and the outside diameter (OD) of the pulley.  The groove angle changes as the pulley gets larger or smaller.

To measure the effective Pitch Diameter (or PD) of the belt, we simply measure over a pair of dowel pins.  The pin diameter changes depending on the groove type.

Lots of manufacturers of pulleys (we actually call them "sheaves") use a form tool to generate the V-form of the pulley groove.  But, I have found that this gives bad angles, chatter in the grooves, bad flank finish, and deformation of the web between the grooves...which can throw off the PD of one or more of the grooves.  So, for the last 35 years or so, I have been profiling the grooves with a 35-degree insert.  This gives far better groove integrity than can be achieved with a form tool.

Let me know if I can help with anything on this.

Thanks, interesting points.

[Freightrain]

Awesome information.  Just to show the vast variety of knowledge that is available from people on forums like this.

[h67st]

I meant to post these photos earlier...I had the pump and injectors rebuilt at a local shop, they charged $1,100 to rebuild the pump and $500 for the injectors. Looks like they paid a lot of attention to detail and the truck seems to run well (that is, without a load on it).

I painted a bunch of parts.

Some of those parts installed.