850-T Engine

[Hahnda]

Yep, its a crusty one. It was in a minor garage fire and then the bike sat outside for a few years. I think the weather was harder on it than the fire was. The only thing damaged from the fire was the points cover. Customer wants it refurbished. All the aluminum will get vapor blasted and should look pretty good again. Supposedly it was rebuilt shortly before the fire. The cylinders are iron bores with 88mm Venoilia pistons. One bore is rusted pretty bad so it will probably be getting a new set of Gilardoni's.

I was a bit surprised to pop off the timing cover and see gears instead of a timing chain.

[Vasco DG]

Gears have obviously been installed after manufacture. If you look at the crank sprocket nut it's on back to front. They look like Eldo gears to me. Charlie would probably know for sure.

Pete

[NCAmother]

Honestly, if the other cylinder is good I would stick with just buying one Venolia 88.  The compression ratio will be same and the motor would be built by you to what the owner planned.

[Hahnda]

Yes gears have been obviously changed. I guess someone didn't like the chain. I think the gear set is from a V7 Sport.

[Vasco DG]

I thought the V7S used the earlier oil pump? I'm not familiar with them though only having worked on a couple. That's why I suggested I hoped Charlie would chime in as he's a wealth of detail knowledge like this.

Pete

[rodekyll]

I too want to know how the oil pump was changed/modified to work with gears.  If you take the pump off, would you snap a few pics for us?

[Hahnda]

I am basing it on that the oil gear has 31 teeth. I think that is what the V7 Sport used. Ambo and Eldo had 29.

[rodekyll]

Assuming the other gears are the same through the models, that suggests the V7 pump shaft is farther away from the crank than the ambo/eldo?

[Hahnda]

I think the V7 Sport used the same pump as the Loops. This is an early 850T with no oil filter. Uses the same pump as the earlier bikes. The pump has the tapered shaft.

[JoeW]

I think the V7 Sport used the same pump as the Loops. This is an early 850T with no oil filter. Uses the same pump as the earlier bikes. The pump has the tapered shaft.

Timing chain bikes use dowels to locate the oil pump, you can see the holes in the block. The driven shaft on a gear driven pump extends into bore in the case.

[rodekyll]

So how is this mod possible?

[JoeW]

So how is this mod possible?

Machine the case to accept the shaft. The pickup and feed ports are in the same place and the wear marks from the pump gears will give an accurate location.

[rodekyll]

hmmmm.

I got me this bare 'paint recall' engine case, a timing gear set and most of the other innards . . . .   Any reason why I shouldn't try it?

[Hymes Inc.]

hmmmm.

I got me this bare 'paint recall' engine case, a timing gear set and most of the other innards . . . .   Any reason why I shouldn't try it?

Do it 

[canuck750]

V7 Sport motor