1968 International School Bus

[whoolieshop]

Picked up a 68 model "race bus" from a good friend of mine as I had been after a bus for some time.

The body / frame are in quite good condition considering the age of this bus, she cranks up and runs great uses no oil and has no oil leaks.

The seats have been removed, and four bunk beds in the rear with a kitchen / seating in the front. A 5' deck is attached to the rear with a stairway up to the roof platform.

Things I know need repair:
1) The brakes have been re-done with new lines and wheel cylinders however the pedal requires you to pump it once before the brakes engage. They will put you in the windshield after one pump so I am not sure if this is a vacuum issue or they simply have air in the lines.

2) Right side exhaust manifold needs to be replaced and exhaust. Right now there is no exhaust on the bus, just past the manifolds, and the right hand manifold is leaking badly.

Are there any suggestions on what else I should check? There appears to be a large brake booster mounted to the frame, also suggestions on where to find a new exhaust manifold would be appreciated!

[Tango]

We need make, model, engine and tranny info at the least to speak with any accuracy.

[cowlitzcoach]

It sounds as if you have a Loadstar chassis with an SV V-8 engine.

The SV V-8 engines used in Scouts, pickups, and Travelalls were identical to the SV V-8 engines used in Loadstars with a few minor changes to fit them into the smaller chassis. The hard parts were all pretty much the same from the first ones made in the late '50's to the end of production in the '80's.

One of the following should have the manifold you need.

IHOnly--http://www.ihonly.com/
IHPartsAmerica--http://www.ihpartsamerica.com/store/
SuperScoutSpecialist--http://www.superscoutspecialists.com/store/p-454-exhaust-manifold-scout-scout-ii-pickup-travelall-gas-v84cyl.aspx


The booster on the frame rail is your hydravac unit. It uses engine vacuum to boost the brakes. When a brake job is done on a rig with a hydravac it is really hard to get all of the air out of the lines. It will take a lot less effort if you get a pressure bleeder to purge the air out of the lines. Trust me when I say that you will wear someone's leg out trying to pump the air out if you have to go through a hydravac unit.

Brake Bleeder Tank
https://store.snapon.com/Non-Diaphra...--P648539.aspx

[whoolieshop]

Originally Posted by Tango

We need make, model, engine and tranny info at the least to speak with any accuracy.

Okay some identifying information!

International Harverster Company

Model: 7.17 GR / 1603
WB 238?
Max GVW 22,000

On the rear of the bus near the emergency exit there's a Thomas Bus Emblem
On the nose a big IH Emblem
and not attached to the bus but inside theres a LoadStar 1600 emblem

[cowlitzcoach]

Model 1603 tells me that you have a 1600 series Loadstar Schoolmaster chassis with a gas engine. 1653 would have been a 1600 series Loadstar Schoolmaster chassis with a diesel engine.

1600 series is generally considered a 2-ton with GVWR in the 16,000 to 24,000 GVWR range. The differences in GVWR were determined by brake and axle groups.

Your bus with a GVWR of 22,000 tells me it is right in the middle of the model range and will have pretty standard and easy to find brake and axle end parts.

[whoolieshop]

Thanks for the info. Don't see my pictures from earlier so I'll try again.






The Whoolie Shop - ATV / UTV lighting & accessories - www.whoolie.com

[whoolieshop]

Originally Posted by cowlitzcoach

Model 1603 tells me that you have a 1600 series Loadstar Schoolmaster chassis with a gas engine. 1653 would have been a 1600 series Loadstar Schoolmaster chassis with a diesel engine.

1600 series is generally considered a 2-ton with GVWR in the 16,000 to 24,000 GVWR range. The differences in GVWR were determined by brake and axle groups.

Your bus with a GVWR of 22,000 tells me it is right in the middle of the model range and will have pretty standard and easy to find brake and axle end parts.

Where would I need to look to figure out which size engine is actually in the bus? the SV V8 came in like 4 configurations it seems.

• SV-266 (266 cu in (4.4 litres))
• SV-304 (304 cu in (5.0 litres))
• SV-345 (345 cu in (5.7 litres))
• SV-392 (392 cu in (6.4 litres))

The bus is equipped with a manual 5 speed with reverse on the left rear (in relation to 1st gear)


I saw on some other threads that the rear end should have some identifying marks to let me know what gear ratio is in them. (I have yet to crawl under and look) She seems to top out at about 48ish MPH.


EDIT: I may have answered my own question above about the engine size, stamped on the identification plate under the hood it states the Net Horsepower is 180.0 @ 4400 RPM. While googling I found a site http://www.binderplanet.com/forums/i...q-specs.94992/ that seems to tie HP ratings to engine sizes:

According to the above site I should have a:
V-304
Brake H.P. (Max) @ RPM 193.1 @ 4400
Brake H.P. (Net) @ RPM 180 @ 4400
Torque (Max) Lb. Ft. @ RPM 272.5 @ 2800
Torque (Net) Lb. Ft. @ RPM 262 @ 2400-2600

There was also mention of a boss near the fuel pump that should have some identification on it but I was unable to locate it.. Mostly because the gull wing hood on the bus doesen't let me get down very low inside the engine compartment.

[cowlitzcoach]

Don't rev that SV engine any faster than about 3500 RPM. Any faster than that and all you are doing is making a lot of noise and using up gas faster.

Many buses of that vintage had top speed gearing of only 47 MPH. I have driven many miles in buses that were geared that way. When you are heading back to the bus garage on a hot spring day afternoon it can feel as if you are never going to get back home again.

With reverse all the way to the left and down I would guess you have the most common 5-speed that has 5th gear direct drive. It is a very good transmission and the gear splits work really well with your engine.

There are other gear sets available. I would not go much faster than top speed of about 60-65 MPH. Any faster and you really start to drink gas in copious quantities. Trying to move that brick any faster will require the engine to really work hard. Which means your manifold vacuum will be way too low. Low manifold vacuum means the power valve will open on the carb and you will be pouring gas through the carb.

That size bus with that size engine 50-55 MPH will be the ideal speed for fuel economy and top speed. Gearing for that top speed will also allow for some hill climbing ability. Any faster and every hill will require downshifting into some pretty low gears.

[whoolieshop]

Originally Posted by cowlitzcoach

Don't rev that SV engine any faster than about 3500 RPM. Any faster than that and all you are doing is making a lot of noise and using up gas faster.

Many buses of that vintage had top speed gearing of only 47 MPH. I have driven many miles in buses that were geared that way. When you are heading back to the bus garage on a hot spring day afternoon it can feel as if you are never going to get back home again.

With reverse all the way to the left and down I would guess you have the most common 5-speed that has 5th gear direct drive. It is a very good transmission and the gear splits work really well with your engine.

There are other gear sets available. I would not go much faster than top speed of about 60-65 MPH. Any faster and you really start to drink gas in copious quantities. Trying to move that brick any faster will require the engine to really work hard. Which means your manifold vacuum will be way too low. Low manifold vacuum means the power valve will open on the carb and you will be pouring gas through the carb.

That size bus with that size engine 50-55 MPH will be the ideal speed for fuel economy and top speed. Gearing for that top speed will also allow for some hill climbing ability. Any faster and every hill will require downshifting into some pretty low gears.

55-60 mph would be my ideal target just for not holding up everyone else on the road constantly. Would a rear end gear or tranny swap be the ideal method for achieving this?

[cowlitzcoach]

Originally Posted by whoolieshop

55-60 mph would be my ideal target just for not holding up everyone else on the road constantly. Would a rear end gear or tranny swap be the ideal method for achieving this?

Because you have spoke wheels the only way to change your top speed would be to change your rear gears or swap your transmission to one with OD gear(s).

It will be much less expensive to rear gear the rear end than to update the transmission to an OD transmission.

IHC used various rear axles over the years. Finding one that will fit should not be that difficult even though the running gear is almost ready for Social Security.

[Brad_SwiftFur]

Having looked into doing an axle gear swap, doing the labor myself, will run me somewhere between $850 - 1000. This will basically get me a rebuilt "chunk" with new ring gear, pinion, pinion bearing and seal, and ... I forget what else. 1 year unlimited mileage warranty. The "chunk" is heavy, somewhere between 250-300 pounds; I'll see about buying/borrowing a transmission jack to remove & replace it when I'm ready. All that is required to remove it is (1) drop the driveshaft (should be 4 bolts), (2) pull the axle shafts (typically 8-10 bolts each), and remove the 10-12 bolts holding the chunk to the axle housing (recommend draining the oil first).