Hello
I am new here and could use some advice from the incredible experience here!
I have a 4107-078 , which needs a motor and transmission
<------ :)
And a "donor bus" Grumman Flx 8V-71/v730
The label in the bus, 1980 Grumman Flxible
Bus Mdl# 53102-8-1
Eng# 8VA402035 Mdl# 8V-71 7087 4523
Trans# V-730 13371 axle ratio 4 5/9 : 1 ?
- - - - -- - - -- - - -
The trans. # plate reads... Model#? 23013542
?? 80J27
V-730-D
I have the manuals for 4107 and the v730 conversion ligature (I'm not sure if it is complete, no wiring for 4107?)
And I will get the Grumman manuals If can use them.
Questions
1. Before I pull the donor motor and make the FlXiblex a "n0n-runner"...Will this motor/trans. Swap work? Electronic control??
If it is DDEC what does this mean for a swap? I have the whole Grumman. It runs and starts great. I think I want the air throttle and shifter?
2. Do I really have to cut/relocate a bolt in the cradle support bracket? Any reports of long term (RV) failures in the modified bulkhead? If properly reinforced?
3. Is there a big enough advantage/difference in the brakes or axle/rear to change it as well? (But not with the Flx's transit 4 5/9 : 1 ?? rear gear)
Thanks for all the Great Information you all have here..
Happy Friday
Jason
I have basically the same setup in my transit conversion. The rear end is probably a 4 5/8 (usually was in fractions) which converts to 4.625. This is the ratio I have and will give you 65 mph at 2100-which is alright to run all day. Although, it be better down around 1800 which is 55mph.
If the doner is a DDEC, then take ALL engine and transmission wiring from the Flx including the gas pedal and shifter. If it is mechanical, then by all means go with the air pedal-I have it and love the light pressure needed. Good Luck, TomC
Here is a site you might lok at he used the engine and transmission from a 1981 Grumman-Flex. http://home.att.net/~kirbybus1/
I also used a engine from a 1980 Grumman-Flex. You have to use the engine cradle from your GM. You have to cut the cradle and relocate the RH cradle to firewall mount to clear the V730. There is a lot of wiring and lines that can be eliminated. The fan drive was different on mine then the GM no angle drive and about 7" shorter. I used a 4.33 rear end ratio which gives me a top speed of about 73mph. A 4.125 will give you abvout 78mph top speed. The data plate on my donor bus also stated 4 5/9 for it's rear end ratio. I have many pictures of this project. I can send some of areas that might help.
We both installed these into GM 4104's. There are differences but the end results is basically the same
Craig C
4104 8V71TA/V730
Lemoore,CA
Craigc at hughes dot net
Hey Oregon, send me your phone number. I have done this engine swap using a 6V92ta. Frank in Idaho