Checklist of changes to swap 1098 for 1275

[tdskip]

Hi guys - hope everyone is doing well and having a good Holiday season.

I scored a healthy 1275 for my Bugeye, and while I should be focused on other projects I'm really eager to do the engine swap.

For planning purposes - what changes or replacements will I need to make to complete the swap from the existing 1098 (itself a swap from the original 998) and a new rib-case transmission?

Seems like new engine mounts etc would be in order since they are going to get touched anyway. Any other make sense things to address?

Thanks in advance for the help!

Tom

 

[bugimike]

Not too many changes, especially with a rib-case AND a 1275 (without the rib-case the switch might involve a new throw-out bearing and perhaps a different clutch fork, and maybe even a shortened/lengthened slave push-rod! New mounts, front and rear (trans) should be done since you have it all out anyway unless they look REALLY good!

 

[drooartz]

I assume the 1098 was running an electric fuel pump, otherwise you'll need to switch out the old mechanical pump as most 1275 blocks don't have the mounting for the mechanical pump.

Just watch the old "while I'm in there" -- or you'll be doing dic brakes, 3.90 rear end, carb rebuild... (I'm there right now).

 

[Jim_Gruber]

Backplates on a 1098 might be different from a 1275 but since you are replacing smoothcase with a rib case you should be in good shape. I'll assume you've already made a conversion to negative ground?

I'll be doing the same swap with Bugsy my '68 Sprite. It came with a "rebuilt" 1098 and a smoothcase. Got a 1275 and a ribcase in the back of the garage that needs a valve job. One of these days it will be "more power", "more power"!

 

[tdskip]

I'll assume you've already made a conversion to negative ground?

Actually, no, not yet. I haven't Does the 1275 set up assume/require negative earth?

 

[bugimike]

No, It is really not a necessary conversion, though I have made the switch!

 

[Jim_Gruber]

Use your generator off of the 1098 so you don't have to repolarize the generator. Also your BE needs a generator with a tach drive off of the back. So reuse what you are using now.

When I first got Bugsy he would start and run as long as you kept squirting gas down the carbs. Could not figure out why he wasn't getting any fuel. I cogitated and cogitated and after about a week, I realized when the DPO installed the 1098 in Bugsy he connected as positive ground instead of negative ground. I disconnected the battery, turned it around, and was rewarded by hearing the fuel pump kick right up and Bugsy fired up and has stayed running well ever since. Amazing enough, even though hooked up backwards, smoke did not come out of the wiring harness, starter worked fine. I repolarized the generator for negative ground and that was that.

 

[tony barnhill]

Somewhere in this thread, you need to compile a complete checklist.

 

[Billm]

While Jim said that his fuelpump didn't work with positive ground I just want to say that it depends on which type of pump you have- the old original SU ones from the '60's didn't care what the polarity was but somewhere in the '70's they put diodes in the circuit so that they would only work one-way (maybe to sell more pumps?).
So if you have an old one (I won't run anything else) just clean the points and keep it running, it will work for a very long time.
Bill

 

[Jim_Gruber]

Yeah, Pump is not an old one. Something newer back there. Again surprised it didn't burn out after being hooked up positive ground.