My 350 Vento

[themoudie]

Aye Sam,

Spanish engineering and neglect in all there glory!

A good engineer/welder should be able to sort your cracked barrel fin/s. Check that the bore isn't squint from the cylinder base and cylinder liner top.

The crankshaft will definitely need splitting and a proper clean/rebuild. As for the rocker arm, build it up with weld and then reprofile, probably the cam will be capput as well. The bunged up centrifugal oil filter having reduced the oil flow to the cam and rockers, there may have been a tempering problem, with the rocker cam pad, to add insult to injury.

All that lot will add at least another £1,000 (Euro 1,200), to £1500 (Euro 1,800) to the rebuild costs, unless you are feeling able to do the work yourself.

Sorry to be a party pooper, but my late Spanish built 350 widecase engine cylinder muff bore had been machined squint and only run for 1,400 miles before the engine stopped, from new! Mototrans quality control was not the best.

I hope that you have the patience and resources to sort the engine out.

Good health, BillR

Google translation:

Salut Sam,

Ingénierie espagnole et négligence dans toute leur splendeur !

Un bon ingénieur/soudeur devrait pouvoir réparer vos ailettes de cylindre fissurées. Vérifiez que l'alésage ne soit pas déformé par rapport à la base du cylindre et au sommet de la chemise.

Le vilebrequin aura certainement besoin d'être fendu et nettoyé/reconstruit correctement. Quant au culbuteur, refaites-le avec de la soudure, puis reprofilez-le ; l'arbre à cames sera probablement également endommagé. Le filtre à huile centrifuge obstrué ayant réduit le débit d'huile vers l'arbre à cames et les culbuteurs, il y a peut-être eu un problème de trempe au niveau du patin de l'arbre à cames, pour couronner le tout.

Tout cela ajoutera au moins 1 000 £ (1 200 €) à 1 500 £ (1 800 €) aux coûts de reconstruction, à moins que vous ne vous sentiez capable de faire le travail vous-même.

Désolé de gâcher la fête, mais l'alésage du silencieux de mon moteur 350 à carter large de fabrication espagnole, récemment construit, avait été usiné en diagonale et n'avait roulé que 2 250 km avant de s'arrêter, depuis son origine ! Le contrôle qualité de Mototrans n'était pas optimal.

J'espère que vous aurez la patience et les ressources nécessaires pour réparer le moteur.

Bonne santé, BillR

[graeme]

A good aluminium welder can repair your fins.
A cam repairer or grinder can regrind your rocker and cam.
Usually built up with stellite first, if done properly it will last.
If not the stellite can crack and flake off.

Good luck.

Graeme

[SamC]

Welding is not a problem for me

I bought all the necessary parts, including a racing camshaft. Regarding the crankshaft, I'm sending it to a specialist company to change the connecting rod.

The cylinder and piston are in good condition ! I did a metrology and everything is within tolerances! I'll just change the segmentation

[SamC]

The engine is on standby while I receive the parts, so I'm getting back to the chassis. And I need some information:

What is the length of the shock absorbers?
Do you have any pictures of the rider footrests? I need to find some.


Thanks

[themoudie]

Aye SamC,

Shock absorber length between the eye centres is 300 mm for the Ducati MKIII and Desmo widecase models. I have fitted 310 mm between eye centres units and this does make a difference to the speed of direction change and clearance, if these things matter to you? But, reverted to 300 mm, as I no longer perch my wife on the pillion!

You can pay all sorts of fancy monies for rear shocks, but I have found that Hagon shocks are perfectly adequate for the everyday road riding that I do and many classic racers over here in the UK, use them as well.

As for the footrests, the folding pillion type footrests that you have on the exhaust side of the machine and fitted to the riders position/behind the brake pedal on the other side would be perfectly adequate, if the OME is difficult, or impossible to find. I am not familiar with the Vento, so Mototrans may even have used the same footrests for both the rider and pillion?

There are loads of images of Vento if you put "Ducati Vento 350" into your preferred search engine. Personally, I would prefer to use the reversed gear lever that you have fitted, rather than the linkage gear change fitted to may Vento in the pictures. Less to wear and give slop in the gearchange, that is already a bit marginal in it's design. At one time I was going to fit rearsets, with linkages, to my 450 MKIII, but ended up making my own pegs, mounted in the pillion position and just using the rear part of the heel and toe lever for gear changes and a wee tap on the front lever, with the heel, to select neutral. Using the reversed lever gives a "down for down" shift pattern, rather than the "up for down", usually found on the MKIII and the Desmo arrangements.

Good health, BillR

[SamC]

I search 310mm shock
Indeed Hagon has a good reputation and the price is attractive.

Concerning the footrests, I only have one that is a little rusty, but I will keep the fixing that allows it to be folded down to make a new one in stainless steel and a fixed one on the right side.

[Jon Pegler]

The Vento originally had 310mm Telesco Hydrabag shock absorbers.
310mm Hagons will be a good substitute.
The standard footpegs were fixed both sides, not folding on the LHS, but unless you have the correct Vento kickstart lever you need to make the LHS peg folding, together with a folding brake lever. This is actually a much better arrangement compared to the standard Vento set up. It allows you to use a straight Ducati kickstart lever instead of the angled Vento item.
Jon

[SamC]

Thanks for the information

[SamC]

More work than I wanted to do to repair the cylinder head.








I received the connecting rod kit and sandblasted the engine parts

[Duccout]

Good progress.