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78 b600 361swap to 429?

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Old 06-11-2018, 12:15 AM
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78 b600 361swap to 429?

Ive got a 78 b600 bus with a 361 and allison allison at540 auto trans, i cant pull a hill over 20 mph, it takes forever to get up to 45mph on flat ground, i cant believe that this is all this turd has got in it! The motor runs good, no smoke or knocking. Im thinking of putting the 429cj from my 3/4ton 4x4 in the bus so it will have more grunt. What will i need to do to put the 429 in place of the 361, or does anybody have any suggestions as to what is keeping my bus from pulling its own weight?
 
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Old 06-11-2018, 08:59 AM
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Make sure the mechanical advance in the distributor is working, and then check the timing.
 
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Old 06-11-2018, 12:12 PM
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Originally Posted by Krewat View Post
Make sure the mechanical advance in the distributor is working, and then check the timing.
Ive taken the cap off the distributor and the advance weights move against the springs, vacuum advance seems to be working as it changes idle when i unplug it from vacuum. Points look newish and gap ok...starts just fine runs good, maybe a pop or two when going down a hill and my foot is off the acccelerator, no smoke or engine knock or ping under load. My vacuum gauge plugged onto the manifold vacuum tree reads "late valve timing/intake manifold leak" but ive checked all my vacuum lines, tightened all clamps, made sure carb is sealed, and sprayed all over the intake w carb cleaner and cant seem to find any leaks. Maybe my timing chain has stretched that its making my valve timing that far off? Im not new to ford v8s or anything else with an engine, but this has me stumped. Im going to pull a compression test today to get solid numbers for each cylinder, but ive usually seen smoke or had another sign of a worn out motor if the compression was low enough to make it as gutless as this is.
 
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Old 06-11-2018, 01:05 PM
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Generally, Fords usually don't have vacuum on their vacuum advance at idle. When you pull it, which way does the idle go, up or down?

Valves that aren't seating (burned or just plain worn) will cause lose of compression, so definitely do the compression check too.
 
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Old 06-11-2018, 09:52 PM
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Idle goes down when i pull vacuum
 
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Old 06-11-2018, 09:56 PM
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As for the motor swap, can i use the flexplate and tc thats on the 361? And will the bell housing match my 429? Motor mounts and exhaust im not worrying about...
 
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Old 06-11-2018, 11:38 PM
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Nothing matches. The 361FT uses a different bell and truck mounts vs. your car 429.

If you want to move this thing down the road you should look into a diesel conversion.
 
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Old 06-11-2018, 11:45 PM
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I'm not sure how much help I can offer, but here's my two cents worth. I've remembered vividly riding in many buses powered by gas engines as a kid. Even had the pleasure of driving a couple of those buses, one a B600 powered by a 361 with a 5 speed (1st was never used to start off). I've even driven a B600 powered by a 361 with an Allison once, and I remembered its top speed was about 45 mph on flat ground. So, going no more than 20 mph climbing up a hill would sound about right. That said, you can tweak around as much as you can with the timing and carb settings all you want but you're likely wasting a lot of time for very little to no reward.

As far as you're intent on an engine swap goes? A 429 V8 is part of Ford's "385" Series V8 engine family if I'm not mistaken. This would be the 370/429/460 family of engines. That said, the bellhousing bolt pattern on your 429 V8 is different from the 361 V8, which I believe is what Ford called their "FT" engine from the 330/361/391 lineup. For lack of a better way of describing it, the "FT" have a much more circular type of pattern compared to that of your 429. I'm not sure as to why you're not worried about engine mounting because if your 429 is coming from a light duty truck, it will be mounted by the left and right sides of the block whereas your 361 is supported at the front of the engine along with the left and right sides of the transmission bellhousing.

Now, Ford did begin using the 370 and 429 engines from 1979 onward, but on those applications I believe the engine was also supported from the front on medium duty truck applications, so I'm not sure if the engine front covers will be medium duty truck application specific (different from the 460 which was used only on passenger cars and light trucks). Your bellhousing issue will likely be your biggest hurdle.

EDIT:85e150six4mtod beat me to the punch!
 
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Old 06-12-2018, 08:03 AM
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Originally Posted by Dbush72 View Post
Idle goes down when i pull vacuum
You shouldn't have vacuum on the vacuum advance. If the vacuum advance dashpot dual-ported or single? And if it's single, it's sticking out towards the front of the vehicle? Where does the vacuum advance line connect to on the carb? Can you post pics?

Vacuum on these should be "ported" vacuum - they should only have vacuum as you step on the gas, not at idle.

If you're using manifold vacuum for vacuum advance, the advance will RETARD as you get into the go-pedal and the engine won't accelerate correctly.
 
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Old 06-12-2018, 07:31 PM
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Ok, so ive just finished compression test...holes 1-4 are 115,115,105,110. Holes 5-8 are 105,105,120,105. Number 3 plug didnt appear that it had been seated fully, it had a bunch of carbon build up around the base of the plug and it only took a couple turns to get it out. Plug number6 was finger "tight" and wiggled when i pulled the plug wire off. Plugs 7 & 8 were tight, but with a thin smooth black covering everything in the combustion chamber like not firing while all 6 other plugs looked nearly new with no appreciable deposits or discoloration.
 
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Old 06-13-2018, 11:53 AM
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Intake manifold gasket leaking. Pull intake off ( caution : heavy ), install new gaskets and correct sealer. Torque down bolts in proper sequence.
 
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Old 06-13-2018, 06:42 PM
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Put new plugs in it, make sure they are in there, and run it for a hundred miles. Pull and recheck. That "smooth black coloring" is the cylinder is rich (soot). I wouldn't jump on an intake leak right away without further diagnosing the issue. Why 7 and 8 would be rich, and the others normal-to-lean, makes me wonder if there really is an intake leak, but I'd run it a bit to make sure.
 
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Old 06-13-2018, 10:54 PM
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Intake vacuum leak would be sucking oil wouldn't it?
 
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Old 06-14-2018, 02:28 AM
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I sprayed carb cleaner allover the intake and carb already, no indication of a leak. Btw, yes the motor was running.
 
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Old 06-14-2018, 02:33 AM
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Originally Posted by m-chan68 View Post
I'm not sure how much help I can offer, but here's my two cents worth. I've remembered vividly riding in many buses powered by gas engines as a kid. Even had the pleasure of driving a couple of those buses, one a B600 powered by a 361 with a 5 speed (1st was never used to start off). I've even driven a B600 powered by a 361 with an Allison once, and I remembered its top speed was about 45 mph on flat ground. So, going no more than 20 mph climbing up a hill would sound about right. That said, you can tweak around as much as you can with the timing and carb settings all you want but you're likely wasting a lot of time for very little to no reward.

As far as you're intent on an engine swap goes? A 429 V8 is part of Ford's "385" Series V8 engine family if I'm not mistaken. This would be the 370/429/460 family of engines. That said, the bellhousing bolt pattern on your 429 V8 is different from the 361 V8, which I believe is what Ford called their "FT" engine from the 330/361/391 lineup. For lack of a better way of describing it, the "FT" have a much more circular type of pattern compared to that of your 429. I'm not sure as to why you're not worried about engine mounting because if your 429 is coming from a light duty truck, it will be mounted by the left and right sides of the block whereas your 361 is supported at the front of the engine along with the left and right sides of the transmission bellhousing.

Now, Ford did begin using the 370 and 429 engines from 1979 onward, but on those applications I believe the engine was also supported from the front on medium duty truck applications, so I'm not sure if the engine front covers will be medium duty truck application specific (different from the 460 which was used only on passenger cars and light trucks). Your bellhousing issue will likely be your biggest hurdle.

EDIT:85e150six4mtod beat me to the punch!
So 45 mph on flat ground and 20 on a hill was the best these busses could /can do? Even when new? My f-ing god!!, How did anyone ever get to where they were going? Theres no way that wouldve been accepted by any school district.!
 
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