Guzzi Racer

[guzzigray]

Hello gentlemen. A quick question regarding the racer i'm building. I'm using a Sport 1100i engine in a Mk 3 Tonti frame and i plan on using the frame tube as a breather (the Mk 3 has this set up as stock). My question is this... will there be enough volume in the tube?? I'm trying to avoid building a breather box. Also would i need to do an oil return line back to the engine and if so would it have to return to a certain point in the engine. There is the option of machining the case and using an oil return line from an earlier engine. Of course if there wouldn't be much oil to return then a simple catch bottle will be much easier.

 

 

I know this is not a V11 question so my apologies. Thanks in advance.

 

 

 

P.S. If someone has a Lemans 1 tank for sale at a reasonable price.........

[Skeeve]

I know this is not a V11 question so my apologies. Thanks in advance.

 

How not? The V11 is just the Sport1100i mill w/ a new ECU & some minor refinements (6 spd gearbox chief among them), after all...

[guzzijack]

Like this? V11Sport engine in high neck, LMV Tonti frame.

 

 

 

http://img339.imageshack.us/my.php?image=p7270502dt7.jpg

 

Third pic didn't thumbnail for some reason - click on link.

 

GJ

[jihem]

My question is this... will there be enough volume in the tube??

 

Just to give you an idea, the Ghezzi frame is also used as an airbox, and I believe it boasts more volume than a Tonti.

There are two small entrance at the front. to suck air in. While this set-up works well when the engine isn't touched, adding a Scola cam and race exhausts made the breathing inadequate and no more could the frame be used as airbox and we had to find other ways to have the engine breathing enough so the "additional power" (cough...cough...) could be dialled in correctly. Hope this helps !

 

[guzzigray]

Like this? V11Sport engine in high neck, LMV Tonti frame.

 

 

 

http://img339.imageshack.us/my.php?image=p7270502dt7.jpg

 

Third pic didn't thumbnail for some reason - click on link.

 

GJ

 

 

Thanks for the pix. Looks like we're on the same track. Mine's a Lemans1/3 lookalike, i'll post some more shots.

[guzzijack]

Thanks for the pix. Looks like we're on the same track. Mine's a Lemans1/3 lookalike, i'll post some more shots.

 

Guzzigray - as you have probably gathered I welded shut the R/H oil return spigot on the Tonti frame crossmember, cut off the L/H one and welded a larger boss onto it so I could drill and tap for a suitably sized banjo for the braided steel oil return line, which I think came from an 1100 Sport. Don't be tempted to make up a larger diameter return line than the O/E one. Guzziology warns against it - something to do with the engine plumbing needing that specific size to create some backpressure to avoid reverse flow? Are you using an oil cooler?

 

Jihem - I think you are at cross-purposes on this one. It's the engine oil breather system not the airbox.

 

GJ

[jihem]

Jihem - I think you are at cross-purposes on this one. It's the engine oil breather system not the airbox.

 

 

yes, i stepped on my english

[motoguzznix]

Gray

 

My suggestion is the Tonti frame will not have enough volume to breathe a 1100cc race engine.

 

Dynotec has a good solution:

They install a breather box into the frame by welding some sheet metal behind the steering head. Thus reinforcing the frame and building a brether box. The return line must always lead to well below the oil level, otherwise the crank case pressure also occurs in your breather box.

[guzzigray]

Great responses and thanks for the imput.

 

Guzzijack: thanks for the advice re: oem hose. I have the Sport 1100 original hose x2. I'll take your advice and weld up a lug to accept the hose. Yes i'm going to run the oil cooler (again , the oem one from the Sporti) The sump has 2 fittings for oil return. I was planning on using just the one like the newer V11's and block off the second one. Also i think it might be a good idea to put a filter in the return line. I cleaned the frame and its amazing the amount of hardened oil deposits and scale that came out!!!! not to mention swarf that will go into the frame from welding, tapping etc.

 

Motoguzznix: how much volume would you recommend?? You're spoiling my carefully thought out plans

 

Thanks again and please feel free to offer any thoughts or ideas. This is an important part of the project and i want to get it right. The idea of pumping 4 qt's of oil over the bike and a track is not a good one.