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LeMans III Superbike Race-Build - Please Advise

FreshEgg

Just got it firing!
Joined
Feb 11, 2012
Messages
15
Location
Seattle, WA
(Cross-posted to WildGuzzi.com)
Hi All:

Just obtained a beater LeMansIII clothed in T3 bodywork from the fairing back and oddly equipped with 2 left-hand PHM40s. Mileage is 90K. I'm hoping to build a vintage racer to superbike spec (rules in red, below) and run it in Washington Motorcycle Roadracing Assoc (WMRRA) events. I'm a Moto Guzzi newbie and have some questions for the racers, builders and experts on this board. Please comment on my off-the-cuff speculations that follow for best plan and cost-benefit:

(1) Engine - Bike comes with 1000cc jugs (SP1000?) combined with 850 LeMans heads. Keep this combo. Send heads to Mike Rich for dual plugs, rebuild and port job. Rebuild the short block locally. Timing Gears? Carillo Rods? Oil Cooler?

(2) Carbs - Dellorto PHM40s. Does the Keihin FCR41 kit for 1100Sport offer much benefit? Anyone have right-hand PHM 40 to trade or sell? Please PM me.

(3) Race Rubber - Are the Avon AM22 and AM23 the only option for the stock LM III's 18" wheels?? Options for race slicks??

(4) Front-end / Swingarm swap - SV650 front-end swap with RaceTech emulators or FZR same. Will an LM IV swingarm bolt on to allow 18X130 section tire??

(5) Bodywork - Anyone have LM III tank, seat, tail and fender for sale?? Please PM me.

(6) Fabrication - Please recommend bike-friendly machinist and fabricators in Seatle area.

Sorry for long post. Your collective expertise much appreciated.

Jin
Seattle, WA



5. Classic Superbike class regulations.
a. Includes model years 1973 through 1985.
b. The classes consist of:
I. Lightweight Classic Superbike (up to 550cc)
II. Classic Superbike (up to 1025cc)

The intent of the reintroduction of this class is to replicate the AMA Superbike class from 1976 through 1982. Participants are encouraged to build machines in the spirit of that series. Tubular handlebars only unless the machine came with clipons stock. No aftermarket fairings – only bikes that came with fairings stock should have a fairing, and it should be a silhouette of the OEM fairing (Suzuki GS1000S, Kawasaki KZ1000R, Ducati 900SS, Moto Guzzi LeMans, BMW R90S, Suzuki Katana). Machines should retain the stock seat bases, headlight shells and fenders as required in the series. Displacement should be 1025cc max.

Actual reproductions of specific period machines are strongly encouraged, including removing and rewelding steering heads to change steering head angle ala Wes Cooley and Reg Pridmore’s bikes, frame bracing of the era, reproductions of Calfab swingarms, etc.
47
As a concession to the lack of race rubber in 18” sizes, changing to 17” wheels (including changing front forks/triple clamps) is allowed/encouraged. Forks should look of the era – ie no upside down forks. For instance – SV650 wheels/forks/brakes fit on GS1000s with very minor modifications.
c. Engines must be air cooled.
d. Rear suspension must be twin shock.
6. General vintage regulations: applies to all vintage and classic superbike classes.
a. Modifications may be carried out to upgrade a motorcycle to period specification only. No components are allowed that fall outside of the era of the class.
b. Downgrading of racing machines is not permitted.
 
Late model Cali forks, 40mm with adjustable compression & rebound, have Brembo goldlines.
Spoked wheels means different rim sizes can be laced up, although Guzzi hubs are made of lead.
 
hey Freshie,

Sounds like a real adventure!

I started racing with a '73 V7 Sport. A real eBay basket case. I wanted to set a new world speed record using a Guzzi.

So:

Phile Wyatt heads. Extreme modifications plus dual plug... more about that later...

Using stock timing gears... considering straight cut but can't really see an HP improvement there. Since the bike only runs about 2 minutes per run... the wear really isn't an issue...

Carillo rods. Man are they Expensive! The BOLTS are $40 EACH!!! I felt very comfortable using them for 3 years but the price of $160 for four stinking bolts (plus tax and shipping) gets to ya if you want to replace them every time you check the bearings. I mean how much are you really gaining here? ... I still use em.

My cam is a Mega Cycle beast. 620X7 Required extensive piston modification$, exhaust manipulation, copper gasket thickness tweeking, on and on. CP billet pistons needed due to the crazy cam overlap. Absolutely horrible compression unless pistons are carefully made.

In my case, Land Speed Racing, the bike must not show modifications. The dual plug was noticed at Speed Week this year and we were put into modified class... we are not competitive in that class (Pepperoni Bros. V7 Sport sure is) so we are going back to single plugs etc.

Anyway.. after 3 years of effort and dough we put a new world record up in 2010 (reset by Big D's Norton this year!). But learned a few things along the way.


Some notes:

Pay attention to the regulations. You can blow tens of thousands of dollars making a Guzzi beast ... only to hafta redo it, maybe, later.

Get access to a dyno. Learn it. Use it. Check, modify, check, modify...

Start with the cam. Get an idea of what ya wanna do and talk to a pro before ya buy anything. Mike Rich has been very kind to me, explaining all of the aspects of what he offers. He is NOT CHEAP... but that's racing. If you wanna win... being cheap will not make ya go faster etc. Spending the most will not make ya the winner... find someone you enjoy working with.

As far as the rest of your questions... coolers, body work, swing arm ... out of my experience.

Good luck. Post some pics.

Ciao

Alex
 
Carillo rods. Man are they Expensive! The BOLTS are $40 EACH!!! I felt very comfortable using them for 3 years but the price of $160 for four stinking bolts (plus tax and shipping) gets to ya if you want to replace them every time you check the bearings. I mean how much are you really gaining here? ... I still use em.


Carrillo bolts are re-useable.Use their rod bolt lube too. Good stuff.

Use a rod bolt stretch gauge. If you use the same lube and torque wrench you'll have consistent results when re torquing if you aren't able to measure stretch.

I experimented with Red Line assembly lube and Carrillo lube and found different torque setting to achieve the necessary stretch so all lubes are not equal. e.g. with Carrillo lube I use 38lbs. With the Redline I would have needed over 40lbs which exceeds Carrillos recommendations.

The great thing about Carrillos is once installed you know there won't be any problems so you gain peace of mind which is important when you're win ding the bike to 8K and above.

And they are WAY lighter than stock.
 
FreshEgg said:
(Cross-posted to WildGuzzi.com)
Hi All:

(1) Engine - Bike comes with 1000cc jugs (SP1000?) combined with 850 LeMans heads. Keep this combo. Send heads to Mike Rich for dual plugs, rebuild and port job. Rebuild the short block locally. Timing Gears? Carillo Rods? Oil Cooler?

(2) Carbs - Dellorto PHM40s. Does the Keihin FCR41 kit for 1100Sport offer much benefit? Anyone have right-hand PHM 40 to trade or sell? Please PM me.

(3) Race Rubber - Are the Avon AM22 and AM23 the only option for the stock LM III's 18" wheels?? Options for race slicks??

(4) Front-end / Swingarm swap - SV650 front-end swap with RaceTech emulators or FZR same. Will an LM IV swingarm bolt on to allow 18X130 section tire??

(6) Fabrication - Please recommend bike-friendly machinist and fabricators in Seatle area.

Sorry for long post. Your collective expertise much appreciated.

Jin
Seattle, WA

I can only give you my perhaps very personal opinion:

1. try to get somebody knowledgable with heads and serious experience in (like valve reangling) porting work to port you the heads and mount preferably 47mm valves since imho the Lm Valves are way too small.
Imho ascan example bill jones from salt lake city would come to mind as he is a porting god with decades of experience and reasonable prices.
Get the thing bored and sleeved up to 90mm´s than you have less valve deshrouding and better flow.
I got told that for a racebuild a good modern (guess like the stucchi or agostini) camchaintensioner does more than enough, thus no need for camgears. Besides most of the modern camgear kits are "all" aluminum and therefore have somewhat a tendency to galling.

2. I also have two identical carbs since a lot of people get them of single cylinder bike demolitions and the pricetag is therefore a lot cheaper.
Personally i think the FCR carb is a far superior carb alone for throttle response, thanks to the flatslide.

3. Wouldnt know bout race tires i allways used bridgestone BT45´s that alone was allready a nice improvement.

4. Cant say too much bout the fork as i have myself a marzocchi MR1 of a bimota breaker

5. CAMSHAFT: Imho forget about all that flimsy moody megacycle business end (unfortunately they seem in terms of customer service a lil moody, so to say)
My recommendation: try to contact the american headquarters of the AVL/Schrick corporation.
They have a very nice semi-modern Race grind that has reasonable lift (bout 12mm´s) nice duration (bout 270ish) and best of all is reasonable priced and precisely ground.

Good luck and kind regards

christian
 
Hi, here are some of my experiences:

A stock LM4 or 950cc LM3 engine is surprisingly competitive. If you are not already a very experienced racer, don’t bother to try to hot-rod your engine. Just rebuild it and get it right as it is. Instead put your efforts into lighten the bike and set it up with good suspension. If you have a limited budget, the best way to spend your money is on good rubber and track time.

The Avon AM22/23 in race compound are VERY good rubber – on the same level as modern slicks. BT45’s are very good street tyres. OK for a track day but not for real racing.

IF you dive into engine modifications, this is my tips:

- The heads don't need expensive porting: The valve lift is so modest on a Guzzi (even with a race cam) that the valve and seat always will be the restricting area anyway. Just clean up the seats and transition from seats to port.
- Long duration cams are not easy to really get power from. Just use an 1100 cam or some other medium duration, high lift cam. Avoid long overlap so you don’t have to recess the valves and/or use high dome, slow burning pistons. I have good experience with HTMoto cam kits. (Germany)
- Get the squish right. 1.0mm seems to work.
- Twin sparks are beneficial in a big valve, high dome engine. Let you run slightly higher compression and slightly higher ignition.
- On a 850 or 950cc engine the stock LMIII heads and valves will make almost as much power as the LM4/1100sport/1200 2V heads with 47/40mm valves – with a nicer power band.
- You don’t need Carillos unless you seriously hot-rod your engine. Just be sure to get new GUZZI bolts, not Chinese pattern bolts. If you do use Carillos, you need to rebalance the crank – which you also need to do if you change to pistons with a different weight.
- Stock Guzzi parts are always preferable over after marked parts. Superior quality and easily available. For big-bore conversion, use stock 92 or 95mm pistons and cylinders. The 95mm items are especially nice and give you serious power with stock big valve heads and a high lifting cam. Just be aware that they are made for 80 and 81.2mm stroke so you have to shorten your cylinders if you run them in a 78mm stroke engine.
- Buy an oil thermometer (the easiest are the type you screw into the dipstick hole) and check (during a race) whether you need an oil-cooler. Depends on power in your engine, driving style, compression, ignition and carburation. Get a cooler if you exceed 120-125 degree Celsius.
- Get your carburation right. Either on a dyno or with a lambda meter ala Innovate.
- Get a RAM clutch
- Modify your gearbox by milling away every second “dog” on all the gears and rings. Makes it shift a lot more positive.
 
Ups, forgot to mention the differences in pin hight for stock Guzzi pistons:

All big block Guzzi engines run the same cylinder hight. There are however two different con rod length: Up to and including 1100 Sport and V11 use 140mm con rods, Griso1100/1200, Breva1100/1200 and so on use 144mm con rods.

The pistons vary accordingly, the pin hole are 4mm higher on the newer items so you actually need the longer con rods for running the new type pistons in an old engine.....
 
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