what do I need to fit a tonti engine in a loop frame

[amamet]

I have a lemans IV project and an eldorado project. was toying with the idea of sticking the lemans engine in the loop frame. why?, why not. I like to keep busy and have fun playing with these bikes. I know the 4ls doesn't have adequate stopping power for the engines power.  again just thinking about it.
-Allen

[guzzisteve]

Something like this--------

[Antietam Classic Cycle]

Didn't we discuss this same topic back in the Winter?

[amamet]

This was discussed recently, I usually bookmark interesting discussions but can’t seem to find the thread. I know I’d have to drill and tap for the alt bracket, but I also remember some discussion about the lower mounting mods.

[GeorgiaGuzzi]

If you have access to a fab shop anything’s the limit! Kinda like racing, how fast you want to go is entirely dependent on your budget! 😀

[Antietam Classic Cycle]

You need to decide which way you want to go about the swap. There are two ways basically:
1. retain the crank mounted alternator and make adapter brackets as guzzisteve posted above. The alternator cover may interfere with the front fender brace, which can be rotated downward after new holes are drilled.
2. swap the Loop timing cover onto the later engine, use a crank adapter to mount the belt pulley, drill and tap holes for the generator on the top of the engine case.

Then there is a decision to be made about the ignition - dual-point timer or single point distributor?

Loop headpipes will need adapters or different flanges to seal properly in the cylinder heads.

[dxhall]

Mike Tiberio may chime in here, but he told me that the motor mount in the diagram was his original design and that it broke.  Here’s an early mock-up photo of the ones I made:





These differ from Mike’s in that they don’t have a step.  The final version has hardened washers in spotfaced bolt holes.

You can see that the Tonti motor is a tight fit in the loop frame, but it does fit.

[Tom H]

Loop headpipes will need adapters or different flanges to seal properly in the cylinder heads.

With all due respect. Stock loop headers will fit at least round fin Tonti. You need to use 2 Tonti exhaust gaskets. Set the gaskets on the header, if the Loop pipe is past the 2 gaskets, add another or trim the header. If you go with 3 gaskets, you will most likely need longer exhaust studs.

Tom

[Antietam Classic Cycle]

With all due respect. Stock loop headers will fit at least round fin Tonti. You need to use 2 Tonti exhaust gaskets. Set the gaskets on the header, if the Loop pipe is past the 2 gaskets, add another or trim the header. If you go with 3 gaskets, you will most likely need longer exhaust studs.

Tom

I did it that way once and it leaked and eventually burned through one of the gaskets. I had a set of stainless headpipes made with the Loop curve but Tonti style flanges and never had any problems after that.

[Tom H]

I will have to keep an eye and ear on that.

I have heard that you can also just cut off the nipple of the Loop header leaving just the flange and use one Tonti gasket. What do you think?

I wanted to keep my headers stock in case I needed them for a Loop.

Tom