69/70 front isolastic with spring

OK, starting a new one here. I took off the exhaust, carbys, front engine mount, loosened shocks at rear, so now the engine/cradle/etc. should all be suspended by the rear iso mount. Unless I'm missing something. Spring is installed but no head steady. I tensioned the spring at 1.5" before removing all this stuff. When I take out the front engine mount bolt, the whole engine drops down and the only thing stopping it from going farther down is the cradle hits the frame brace by the sump, remember this is a 69. I can jack up the engine and when the front mount center iso holes line up with the frame holes, it lines up pretty good, within 1/16", so I don't really have to push things around to get the bolt through all the holes. I measured from the front iso bolt center to the rear iso stud center and I get real close to 18.28" as close as I can measure with a tape. So nothing appears completely whacked out with the frame. The distance from the rear iso to the shock top is also 12 5/16" real close to spec.

So what's the deal with the spring? It's certainly not holding the engine up to keep the weight off the front isos and even if I tighten up the spring, it still just drops down and the cradle hits the frame brace. Or is this just the way it is? I thought the spring would hold the engine up so the front isos aren't pre-loaded?



Dave
69S

Dave, FWIW, I did some measurements on the spring in this thread:

post89775.html#p89775

Dave, I think I read somewhere that the spring is intended only as a "support'

and was never meant nor engineered strong enough to actually support all that weight

I have the Comnoz CNW head steady, without the optional spring, and it works every bit as well as the Dave Taylor
with the spring that I had before

Edit:

I think perhaps you are expecting too much of the spring?

OK, I saw that thread on the spring earlier when I was looking around. BTW LAB, I now have the spring on the correct way, it looks to pull straighter that way, I just have to take the coils off to adjust it. Yes, maybe I'm expecting too much. I had been thinking after I saw how much my front isos droop (without the gaters) that if I could get it centered so there was no pre-load to the isos it may reduce the vibrations a bit. I guess I'll live with what I've got, and go on with my aluminum Taglieri head steady project. I've got all the parts now except a few bolts and they should arrive today. At least I know my frame is not all whacked out of dimension. I was wondering about that.

I'll have to play with the spring adjustment when I get everything back together and on the road again. It's been too hot and muggy anyhow. It's not bad in the garage with the fan on.

On the other hand, ludwig only puts a 44lb or 20kg spring on his.

Dave
69S

Dave,

Is the spring hung from the forward lip of the saddle, or the rearward lip?

If it's on the rear lip, try re-hanging it from the forward lip.

On the front (tightest) one.

Dave