Camshaft/Layshaft questions.

I'm looking into something for a racing engine.

How hard would it be ( and how expensive )
to have a layshaft made to run in place of the cam (in block, pushrod engine)

I couldn't use an actual cam as a layshaft because it would need to be lengthened, and a second cam shaft sprocket would have to be fitted to the lengthened side.

Unless there would be a way to lengthen a camshaft and machine it so it would accept the sprocket...

The lay shaft would not have to have any cams on it since it would not open the valves anymore.

( it would drive two different camshafts, instead...)


The actual identity of the engine doesn't matter ( mostly because its Off Topic )

But I bet that you guys can figure out from the way I've worded my question what I'm trying to do.

 

Magic acronym...TGP, turned ground and polished shafting. Available in various lengths for every engine alchemist. Wouldn't there be advantages though, to belting directly to the newer cams?

 

I'm looking into maybe doing a headswap on a vintage engine.

The head happens to fit better backwards than it does with the drive side of the cams on the drive side of the engine.

It looks like I might have ( almost? ) enough space to drive the new cams off the back of the old camshaft ( but it would need to be longer, and it would need a sprocket )

I can buy the parts to reverse spin the old camshaft so it would match the rotation of the new cams.
( those are available off the shelf )

 

First, I think all cams are chilled cast iron, so adding on is probably not the best idea. I don't know if all cam bearings in your engine are the same diameter, so the TG&P idea may, or may not work. (great if it does) Making a straight shaft with bump-ups to journal diameter shouldn't be too expensive. I'm guessing at $150 = material. Take all your pieces to a good job shop and tell them what you want and let them measure your parts so you get the correct "fit". I don't think most automotive machine shops would have the right kind of lathe to do the work.

 

3 different sizes of bearings, unfortunately.

About 31mm , 43mm , 38mm.

But I could sleeve the bigger ones back to the size of the smallest one.


There is one critical thing, though.

The layshaft would have to have the oilpump drive gear, that is on the camshaft...


Thanks for the Info, guys.

This is really helping me out a lot.

 

Any decent machinest could make one, to your exact specs.

I had a Cadillac flathead cam blank made, and it cost $500 dollars. I would think you could get one made for half of that.

Off topic or not, I'd sure like to see this DOHC conversion!

 

Thanks for the Info.

For pics look in my Misc. Album.

They are next to the little red car this engine would be going into...

 

I might be able to simplify it a bit.

By not putting a layshaft through the camshaft bearings, but have a gilmerbelt driven layshaft on the outside of the engine.

That would mean I'd have to reverse the rotation of the overhead cams, but since they are two separate cams ( one for intake one for Exhaust ), and the ramps look symmetrical ( at 1st glance...) that shouldn't be a problem.


Thanks again for all the Info, guys.

I really appreciate it.