1000 round head vs 1000 square head

[ritratto]

Ok, so, a hypothetical question. Can a 1000 cc round head (G5) engine and frame be make to handle and preform as well as a 1000 square head ( LeMans etc. ) without spending a fortune? It has right now new fac dampers and progressive springs up from and Koni's in the back, a LeMans II tank and foot peg setup. Engine is basically stock with rebuilt tranny (MPH) and VHB carbs. I can easily put the CX100 clipons on to improve riding position. Exhaust and jetting?

So, what say ye folks?

[Piglet]

It should handle every bit as well.  They're basically the same bike.  Maybe getting the rider lower with the scooped out seat might help.  My Lemans II had a tubular bar on top, and never came with the proper clip-ons, thank goodness.  I liked my IKON shocks which were essentially KONIs I suppose.  Exhaust and jetting is another thing.  If I had to hop up a small valve engine, I'd probably just install  36 or 40mm round slides or even Mikunis (shock horror...) and see how far that got me.  They're supposed to do a lot

[Perazzimx14]

What is you defination of "fortune"? If its a couple hundred dollars the answer is no.

[ritratto]

No, but maybe less than a grand. I have quite a bit in it at this point. Pic below.

[blackcat]

I have an 81 CX with 36mm delorto's, lightened flywheel and some sort of cam that I can't remember, but it was a drop in. Yes, it's better than stock but it isn't going to pull off my arms and it isn't even close to my 1000S. Well, it's closer that it was in stock form.

I could put in a lumpier cam, have the head flowed,etc.etc. but why? It is what it is.

[Aaron D.]

If your goal is to ride fast with friends on twisty roads, put the money into suspension and you'll likely be able to keep up with anyone, within reason. And within budget.

If your goal is to blast 600 SuperSport bikes on a track, cheaper to sell the Guzzi and use the money for an R6.

If you want to replicate a proper LM, never for under $1000, not really, but not really necessary.

[PeteS]

Are the 1000 LeMans heads and pistons the same as the G5's as far as compression and valve sizes? My guess is no. I would expect differences like a T3 vs 850 LeMans.
If they are different then you would have throw much more money at it to make them perform the same.

Pete

[ritratto]

OK, so Blackcat and Pete have given me what I was after. To make as much as possible like my 1000S was the goal. I guess I should keep as is and makebe later add some better pipes and carbs and be happy.

Thanks guys.

[blackcat]

Install one of Ed Milich's lightened flywheels.

[Arizona Wayne]

Part of what you want comes down to weight.  The original LeMans versions have thinner wall tubing than the more robust Guzzi models, so no matter what you do to the motors they're not going to weigh as little as the earlier LeMans models did.  I had a `87 LM IV that pretty much stock would do 139 mph top speed.  The factory claimed 145 mph top speed.  Part of speeds like that is aerodynamics   My LM IV made 61 dyno hp. but it was designed in a wind tunnel too.   1 time I got in a race with a brand new Camaro tested w/a 140mph stop speed and drafted it since it was barely faster than my LM IV.   When we went from a 4 lane to a 2 lane road he had to hit his brakes, where as I passed him and the cars he had to slow down for.      That's when I decided it was time I got rid of my LM IV before I got nailed.   

[Arizona Wayne]

The non sporty Guzzis have smaller carbs and smaller valves than the sporty Le Mans types.  But that means you have to rev the carbs more to get acceleration on the faster bikes.  I like to get good gas mileage and run @ 4-4.5K rpm.  My small valve(SP) `81 CX100(Le Mans chassis w/SP motor) has more midrange and then the cam kicks in @ 5,500 rpm for more ripping acceleration, but I hardly ever go there.  On the street midrange is where it's at.

Bigger valves on Guzzi heads mean more wear on valve guides.  Smaller Guzzi valves are trouble free.  I've been riding Guzzis for 30 years and have 3 right now, `81 CX100, '04 750 Breva. `77 Convert. acquired in that order of those I haven't sold( `80 Convert., `87 LM IV)._

[Tom]

Biggest improvement is the ecu in your head.  Rev higher before shifting and maintain the rev's.  You'll never get the round head to out perform a square head.  All the tweaking and the gains are minimal.  Usable horsepower is there.  Just making sure how to use it is another story. 

[trumps]

Well from my experience you can make reasonable and very useable power fromm the small valve round fin 1000.
I built my 1000SP/NT engine last year, has now got over 7000km on it, and it has proven to be a joy to ride.
Spec I went with were
 B10 cam stock valves, with heavy duty springs
 new Phf36's with straight manifolds porting cleaned up and matched K&N's
 C5 optical ignition
 HT Moto exhaust
 Ergal aluminium flywheel, lightened pressure plate std twin plate deep spline clutch
 sump spacer

the motor is beautifully responsive, I run it to 7500rpm max, and push it pretty hard quite regularly
obviously it isn't a massive power house, but power and torque are totally linear in delivery.
the attached dyno chart was done with the motor only having about 1000kms on it and has freed up
since then and I would think has picked up a little more go. very happy with it. i figure it is
in the ballpark with a early lemans performance wise, going on the numbers i have heard bandied about
being as my figures are at the rear wheel, where as all quoted numbers from guzzi seem to be flywheel!

Craig

[Gliderjohn]

Had fairly similar results on my T-3.
!,000cc kit
V-7 Sport cam
36mm round slides
Ported and polished heads
S&W valve springs
K&N filters
$80 Emgo Dunstill replica mufflers

GliderJohn

[ritratto]

So Craig and John,

About what did you spend getting these results. It does seem like a good way to go. Cam, flywheel and carbs. Already has the sump spacer.

Ted

[Gliderjohn]

That was about 15 years ago so trying to go by memory. With parts and labor (I did nothing) it was about $2,400 or so. It is a wonderful real world motor.
I have tried a lightened flywheel and really could not tell any significant difference. When it was on the dyno it had the stock flywheel. The only regret is not balancing. It does have a bit more vibration and at cruising speeds it tends to make my nose itch of all things which can get annoying after a while. Another rider that had the almost exact same setup in an Eldo did 80 miles at 105 mph avg. with no issues.
GliderJohn

[cwiseman]

After my recent a Eldo engine rebuild with all the goodies I say the $2400.00 mark is about spot on. I will probably not get her on a Dyno any time soon but low to mid 50's for HP should be about right

[trumps]

Hiya ritratto, mate to be honest I could not put a figure on it as I rebuilt the whole bike at the same time, also I did a few things which were not strictly necessary like th C-5 ignition, and brand new carbs, along with new pistons and barrels. I tend to go over the top on these things and many would say they aren't required but I built this bike with the idea of being able to flog the daylight a out of it,
And for it to remain as drama free and reliable as possible in the process. I have too many other bikes that are finicky and require constant tuning and attention to add another to the fleet LOL!

[ritratto]

Ok Craig,

So which flywheel, clutch, pistons and barrels did you use?

Ted

[trumps]

Hello Ted,
I am running an Ergal 3lb flywheel, with lightened ring gear, std twin plate deep spline clutch. and Gillardoni pistons and barrels.

a couple of the reasons I wanted to build the guzzi to be as hassle free as possible LOL!



Craig

[Murray]

OK, so Blackcat and Pete have given me what I was after. To make as much as possible like my 1000S was the goal. I guess I should keep as is and makebe later add some better pipes and carbs and be happy.

Thanks guys.

Niksil Big valve motor verses small valve iron lined or similar, would be cheaper and quicker to update the motor in entirety.

[blackcat]

http://www.guzzipower.com/store/Flywheellightening.html
$500 bucks.

36 mm carbs will cost $300 each + or -.

http://www.mgcycle.com/index.php?main_page=product_info&cPath=68_129&products_id=2128
$342.00.

http://www.guzzipower.com/store/Camlifter.html
Megacycle cam- $450.

$2k plus with your labor.

[charlie b]

I went through several calculations on how to increase the power of my T5.  I ended up above the $2500 mark as well.  Decided I could buy a bike with the right motor for not much more so I left my bike as is.

[cwiseman]

Ok Craig,

So which flywheel, clutch, pistons and barrels did you use?

Ted

Well this Craig used stock eldo flywheel lightened 1 Pound, Stock 4mm spline clutches for a modern big block 1100, G-doni 950 kit, stock carbs and a C5 ignition, ported heads and mega cycle 620X3 cam.
Just tonight I got the carbs dialed in darned close with bigger pilots and mains, WOW what a difference that made! This thing pulls like a train now

[trumps]

Well this Craig used stock eldo flywheel lightened 1 Pound, Stock 4mm spline clutches for a modern big block 1100, G-doni 950 kit, stock carbs and a C5 ignition, ported heads and mega cycle 620X3 cam.
Just tonight I got the carbs dialed in darned close with bigger pilots and mains, WOW what a difference that made! This thing pulls like a train now

sounds like a very nice set up mate, the old girl will be transformed! which carbs 30's or 36's?

[ritratto]

Thanks for all the info everyone! Of course this will take some serious thinking and planning and saving for all the bits. It will be into next year before I get way into it, but like my ol dad always said "Plan your work and work your plan". Still looking at exhaust options as well. When all is said and done, it will essentially be a new motorcycle. A new, and better than original, 1978 motorcycle! And until then, it is still a good ride.

Cheers and best of luck to all in Mandello this weekend!

[cwiseman]

sounds like a very nice set up mate, the old girl will be transformed! which carbs 30's or 36's?

She's running the original VHB29's for the moment, I hope to put some PHF30's on her over the winter.
Just Installed my new Mistral exhaust system & she's running & sounding great.

[trumps]

She's running the original VHB29's for the moment, I hope to put some PHF30's on her over the winter.
Just Installed my new Mistral exhaust system & she's running & sounding great.

if you can go with the 36's mate, much better I would think, they get the most out of the rest of your combo.
it would be sad to do all the rest and starve it on the air and fuel side!

[Gliderjohn]

 :1: on the 36s.
GliderJohn