Gillig engines 6v or Cummins 8.3?

[pengyou]

I have fallen in love with the tall windows of the Gillig Phantoms...I have read that they also have pass through storage underneath...I am in bus heaven! The wikipedia page says that the Cummins 8.3 was an engine option https://en.m.wikipedia.org/wiki/Gill...tom_School_Bus but I have never seen one for sale. The buses I have seen all have the v engine. I can see why that would be convenient because the v engine is probably 30% shorter than an inline 6. Where they just rare? Has anyone ever done an engine swap - replacing one of the two strokes with a more modern engine - an 8.3? My preference now for a drive train would be an 8.3 with a 3060 transmission - in an ideal world. But I would also like to get a bus old enough so that there were no smog devices installed.

[nightanole]

All the school buses had 6V92 (they had 2 HP versions, but the only different was the RPM limiter) and just about all of them had the MT643, which you could say is the mother/father of the 300/3060.

To get a 8.3 mechanical + a 3060 installed, is going to be up to 5x the cost of the bus.

At that point you might as well get creative and try to mount a m11/ism from a garbage truck, using phantom transit model hardware, since they did come wiht m11's.

Also if you do find the school bus, enjoy your 45ft turning radius.

[Iceni John]

If the Phantoms had the 253HP version of the 6V92 they would have used the smaller MT transmission, but if they had the 277HP 6V92 they needed the big HT740 transmission because that engine exceeded the MT's input torque rating. The lower HP 6V92s are fine for level ground but will climb long grades slightly slower than the higher HP 6V92s, but they also have less tendency to overheat because they're burning less fuel. The big 6V92s however have the better transmission: the HT locks in 2nd, 3rd and 4th, while the MT locks only in 3rd and 4th. If you have a bus specced for mountain use with a Jake brake, it won't be much good in 2nd gear if you have a MT.

If you really have to swap engines from a 6V92, a Series 50 is the only practical option, but then the usual 4.10 axle will be too low geared for the Series 50. Just keep with the 6V92 - it's a fine engine if you know how to drive it correctly.

One thing about the high windows and the flattish roof - it prevents using overhead cabinets inside, unless they are very small.

John

[cadillackid]

Originally Posted by Iceni John

If the Phantoms had the 253HP version of the 6V92 they would have used the smaller MT transmission, but if they had the 277HP 6V92 they needed the big HT740 transmission because that engine exceeded the MT's input torque rating. The lower HP 6V92s are fine for level ground but will climb long grades slightly slower than the higher HP 6V92s, but they also have less tendency to overheat because they're burning less fuel. The big 6V92s however have the better transmission: the HT locks in 2nd, 3rd and 4th, while the MT locks only in 3rd and 4th. If you have a bus specced for mountain use with a Jake brake, it won't be much good in 2nd gear if you have a MT.

If you really have to swap engines from a 6V92, a Series 50 is the only practical option, but then the usual 4.10 axle will be too low geared for the Series 50. Just keep with the 6V92 - it's a fine engine if you know how to drive it correctly.

One thing about the high windows and the flattish roof - it prevents using overhead cabinets inside, unless they are very small.

John

you can "program" a 643 to lock in 2nd and in fact they will lock in 2nd on the off-throttle on their own so if you are concerned about descending hills slowly your 643 will stay locked well down into 2nd gear. and at light and light-mid throttle once locked in 2nd will stay locked.. the pan can be dropped and the lockup adjusted on these.. 2nd to 3rd is a bit of a tall shift so running locked in 2nd results in quite an RPM drop... 3rd to 4th is a huge drop as well. and the trans stays locked during the 3-4 shift..



-Christopher