V11 Engine Hot Rodding advice

[Kuni0]

Hello everyone,

 

I was hoping I could get some advice from the great people here and get some opinions/ options to mildly hot-rod my Guzzi motor. 

 

Because of some transmission issues, I had to pull the motor from my Guzzi to diagnose (which I soon discovered was likely caused by literally disintegrated clutch plates) and I figured with over 45k miles, might as well take the opportunity to service and modify my Le Mans as I saw fit, especially with trying to squeeze a little more power out of the motor while still maintaining everyday reliability.

 

What are the opinions on Cams/ Valves/ Springs/ Pushrods, anything else I might be missing?

 

I was looking heavily at the Megacycle 620x10, but I'm unsure of the modifications needed for it. For street use, I've heard the 620x9 is better?

 

Ghezzi Brian also sell a camshaft, but don't list the specs so if anyone knows anything about that I would be interested to hear.

 

I know valves/ springs/ pushrods would help with the motor (and in some cases are necessary for a hotter cam) but I'm pretty lost when it comes to this aspect of Guzzi tuning. 

 

I know for sure I was going to try and find a Roper plate and get the heads ported and polished. I've decided against Hi-comp pistons because of how crappy the fuel can be here in California.

 

This will be a street bike through and through! I don't want to make sacrifices to reliability as I want to continue to tour on it and put thousands of more miles on her. Though I'll take it to a professional when needed, I would like to do most of the work myself when possible.

 

Thanks in advance!

[GuzziMoto]

The cam in the V11 seems to be a really good cam for street use, and likely as hot or hotter than the MC9 cam. If you want more, you are going to likely have to give up some street manners.

My wifes V11 has the stock cam, but has been ported and the heads / cylinders have been machined to set deck height and improve the squish (stock there is no squish). Perhaps a better route to the machining I did is to get a set of Mike Rich pistons that create a squish band without the machining. But they seem to be available only some of the time. If you can get a set that would be a good way to go. Slightly more compression but because of improved squish they are less prone to detonation. I was able to achieve the same basic thing by having the heads and cylinders machined, more compression but less detonation because of improved squish.

I always say that I think the Guzzi motor is a great candidate for hot rodding as there is so much room for improvement, unlike so many other bikes out there that are already sqeezing every last ounce of power out. But be realistic about your expectations, you can get it to make more power, but it will never be as fast as a more modern motor. But there is a joy for some that comes from making things better than they were. And the Guzzi lump is a good candidate for that. There is room for improvement.

[Pressureangle]

Having made every conceivable mod to my '85 LM1000 (save stock displacement/pistons) and riding my stock-but-mufflers-and-ECM '97 1100 sport i 10,000 miles around the country last summer, I'd say the best return on dollar is having the heads done by a *very* competent and experienced porter. Guzzi ports are notoriously poor, but not easy to make enormously better without very specific knowledge; making it worse is that on an injected bike, you can't just raise the ports carelessly as the relationship between the throttle bodies can't change. I'm working that out this summer with my engine guy, but I'll probably have to have the bike in the shop to be certain it all works out. Conceivably it's a simple matter of geometry but I wouldn't take it for granted, and the 45* angle means you can't raise the port along the cylinder axis. 
Given the experience of the stock LMIV, stock 1100 sport, and the modded LMIV, I do not believe that a cam change will net you any satisfactory return for the work involved. You may find more RPM and upstairs performance, but that always comes at the cost of low RPM torque and drivability. 
Also you have to consider tuning; I installed a Jeffries MyECU and it's awesome, but would not be a lot of fun if you have no injection tuning experience. 
So if you can't resist tinkering, let your wallet be your guide; but if you just want to ride it, put pipes on it, tune it, and go faster from the saddle not the motor. 

[Admin Jaap]

And there is a option for twin-spark. Has been done a lot as far as I know.
Here is an old topic: https://www.v11lemans.com/forums/index.php?showtopic=15316

[GuzziMoto]

We ran twin spark conversions on our Ducati 750 racebikes.

I think that is a good idea, especially when you start to increase the compression ratio.

The newer CARC 2 valve motors use them from the factory.

[al_roethlisberger]

We probably need an FAQ for this one day, something like "stage 1" through "stage 3" with the associated list of part numbers, tested power output & benefit, and cost. 

 

The problem is that the population of V11 Sport and Le Mans owners is so small that have tried various options and measured them, and distilling the parts list appropriately, that it is hard to actually produce such a list... as we've discussed over the years.  But it would be nice 

 

 

That being said, I feel like I just commented partially on this topic the other day, and I did 

 

https://www.v11lemans.com/forums/index.php?showtopic=20253&page=3&do=findComment&comment=236884

 

From the thread "Camshaft recommendation needed":

 

https://www.v11lemans.com/forums/index.php?showtopic=20253

 

 

 

 

And this on dual/twin plugs:

 

https://www.v11lemans.com/forums/index.php?showtopic=320&do=findComment&comment=2919

 

From the thread: 

 

https://www.v11lemans.com/forums/index.php?showtopic=320

 

 

 

Hope that helps 

[ScuRoo]

“Guzzi ports are notoriously poor, but not easy to make enormously better” - isn’t this a bit oxymoronic?

 

So what are the specific attributes that makes the stock Guzzi V11 port so poor?

Is it:

• Casting slag restrictions?

• Too long or too short?

• Too narrow or too voluminous?

• SSR drop off too severe?

• Bowl area too big or small?

• MCSA too large?

• Lazy port velocity or choked?

 

Please enlighten & add some meat to the bones of “notoriously poor”??

 

If a port is “not easy to make enormously better” - isn’t this often said is a hallmark of good/great ports, ie., great ports are hard to improve on and so shouldn’t a poor port be easier to improve?

 

These port problem areas would be great to know... head work is on my list!

 

And what makes Chuck’s port’s so mighty?

[Chuck]

Talk to Mike Rich..

[ScuRoo]

Yeah but... I’m sure Mike’s too busy just to natter over our Guzzi’s notoriously poor ports!

 

However, this is what this forum is for isn’t it - bung around a few opinions, share some knowledge, create a worthwhile talking point, challenge viewpoints etc., and in the process there’ll be gems that usually come to light oftentimes...

 

Like for example, there used to be a guy with a Centauro called the beast who had his intake manifolds epoxied to speed flow - Bill Finnegan (hic) recommends filling the SSR port floor by 6 or 7 mm to narrow & D shape it - an old Maico champion (Strosek?) who D ported & hogged on his old LeMans to impressively gain more CFM - even Motoguzznix managed to take moulds of V11 ports but can’t remember if that showed if it was poor or not... then again there’s Wittner’s preference to rework the medium valve heads etc.

 

Without some thots from any narly old Guzzi coots then the status quo won’t expand much! I’m thinking if the new V85 genuinely hits its 80hp spec then maybe our V11 donk could do with a couple of titanium intake valves etc & take some tips from its improved development R&D. Got any drunken thots??

[GuzziMoto]

The issues I have heard of associated to the V11 ports are things like poor layout with a bad bend at the end, issues with the port getting to large in cross section down near the bend, slowing the flow, and the port not having the right flow angle compared to the valve angle.

The port can be either enlarged everywhere to match the large area, which will increase flow but reduce velocity. Or it can have the large are filled to make it more consistent.

But the bend at the end and the angle of the flow at the valve can't easily be corrected. 

But, I still believe there is plenty of room for improvement and at least a few people have shown they can get a fair bit more power out of a V11 lump by porting the heads.

[motortouring]

Wat about nicely litering and loosing some weight from the flywheel.

Balancing the crankshaft.

Installing the windage tray.

 

And I always think high voltage coils make it run better at high refs.

 

These mods all add to better road usable riding.

 

 

Verstuurd met Tapatalk

[Pressureangle]

The issues I have heard of associated to the V11 ports are things like poor layout with a bad bend at the end, issues with the port getting to large in cross section down near the bend, slowing the flow, and the port not having the right flow angle compared to the valve angle.

The port can be either enlarged everywhere to match the large area, which will increase flow but reduce velocity. Or it can have the large are filled to make it more consistent.

But the bend at the end and the angle of the flow at the valve can't easily be corrected. 

But, I still believe there is plenty of room for improvement and at least a few people have shown they can get a fair bit more power out of a V11 lump by porting the heads.

That pretty much covers it. The port floor entry into the valve is the main concern here- it can't have the radius increased without raising the roof to suit, and you can't raise the roof to suit without moving the port mouth to suit. My LM1000 heads flow about 240cfm, but they've been raised a half inch. That is a lot harder to do with EFI since the relationship between the two heads has to stay the same unless you do some serious rethinking of throttle activation and expense. I'm going to examine those possibilities this summer, see if we can come up with a significantly improved port that keeps the stock throttle bodies on their mount. 

The point of the exercise is not to make an extreme racer, but to find something economically viable, reliable, and streetable that you can install in your own garage.

[LowRyter]

You might talk to a local shop that does cylinder head port work and port matching. 

 

I was talking to one of Chuck's friends from Chicago (whose name escapes me) that had a hot rod Loop.  He mentioned he took it to a shop that did a lot of hot rod stuff.  

[ScuRoo]

 

Thanks guys! See, now that was worth it - I’m sure from the number of readers there’ll be many cogs spinning & awhirrin’ around with these thotfull gems.

 

I cannot quite remember where I read this, I think maybe on a Thumper forum but I’ll try & paraphrase what some old hand opined his recommendation to “economically” do to ports - which I retained in my head because it was a ‘best bang for buck porting tip’ I’d heard put forward succinctly.

 

It went something along lines of - if you find someone experienced with porting heads - but hasn’t previously worked on heads like yours before now, just ask him to do his favourite angled valve job, clean up & pocket port only - I seem to recall it was suggested to even excessively hog out on the pocket AND then lay down epoxy for raised flat floors & D shaping the SSR.

 

It wasn’t the nth degree in porting advice but always produced improvement across all & sundry heads .

 

...care to add your thots?

[GuzziMoto]

That sounds like a decent plan. Sometimes it is better to do less than risk doing too much.

I would add that I am a fan of cleaning up and matching the various bits, making sure that the intake manifold matches the port in the head, and making sure the valve seat is blended to the port. Those are simple things to do that on a lump as primitive as a Guzzi can make a decent difference.

Sometimes just making sure you are not adding any more turbulence to the flow then you have to is going to help.

Another area of concern is how you deal with the valve guide. It sticks out into the port at a bad spot, as I recall right before the port turns toward the valve. So improvements there can help a lot.