V7 820cc Kit from Italy

[sign216]

Beowulf saw my V7's 820cc kit on another site, and I told him I'd post the details.  Here you go:

Purchase - Kit is a non-catalog item from Agostini.  Contact is Nicola, who speaks English, and took pains to answer my questions both before and after the sale.  A great sales representative!  The kit is actually put together by R.A.M., a small Italian engine parts firm.  The pistons are made by C.P.S, an Italian custom piston maker.  Both of them were unresponsive when I had issues.

Kit - Consists of big bore cylinders, pistons, rings, wrist pins, and headgaskets.  These are done in small runs, and you must carefully inspect and measure pieces to catch things missed by the makers.
Cylinders - Well made and finished.  Better than you see on some aftermarket Harley kits.  However, an oil passage wasn't shaped to mesh with an oil guide.  Easy to fix, but ...
Pistons - Nicely finished, but with excess metal (and weight).  Stock Guzzi pistons were svelte, trim, and showed efforts to keep the reciprocating piston as light as possible.  This wasn't done with the kit pistons.
Wrist Pins - Here, the kit pins were light.  They were shortened, chamfered, and drilled out to save weight.  Stock Guzzi pins were heavy.
Head Gaskets - Flimsy, without the silicone insert of the Guzzi gasket, and didn't fully match the head.  I fixed the resultant leak, but I won't bore you with those details.

Balancing -
Guzzi Stock 750cc piston + wrist pin = 306 + 100 = 406 gm
Big Bore 820cc piston + wrist pin = 356 + 74 = 430 gm
lightened Big Bore  820 piston + wrist pin = 419 gm       approx. 3% difference = heavier

It would be best to disassemble the engine and balance it with the new components.  I merely took the big bore pistons, which are heavy, to a retired engine machinist (Dunbar of Massachusetts).  He lightened the pistons by 12 gms, leaving the new ones only 3% heavier than stock.   More could have been done, but it would have been difficult.

Warning; you need to adjust the fuel-air mix after doing this, as the increased displacement will lean it out.  I did it w an Aussi programmable Ecu, MyECU.  Also note the engine isn't as smooth as pre-kit.  I compared it to four other 750s at a rally, and my bike's vibrations are within the normal range.  Some were worse, some better.  But I can tell the vibrations are a shade more than before the kit. (perhaps 3% more?).

[sign216]

1st photo w the yellow circle shows the skirt later removed to adjust piston's weight.

2nd is the lightened piston

3rd photo is the beefy kit piston, showing the excess metal.  But the overall quality is still good.

4th photo is the svelte stock Guzzi piston, showing the factory's efforts to lighten it.

last photo is the cylinder that's supplied in the kit.

[TN Mark]

Do you have Before and After dyno graphs and the total cost of the big bore kit?

[Beowulf]

Wow thank you. That is very helpful info. 

[sign216]

Do you have Before and After dyno graphs and the total cost of the big bore kit?

I didn't dyno it.  It's on my list of stuff to do (a list that's never completed).  Reportedly big bore kits increase torque, but don't do much for top end horsepower.  This must be esp true on the orig V7, because the small valves of the Heron head limit top end hp (but increase low to mid torque).  On the Files page of this group, there's a bunch of V7 dyno charts, some w big bore kits, some standard.   https://groups.yahoo.com/neo/groups/MG_750/info

The kit was 550 Euro 8 or 9 yrs ago, from the maker, R.A.M.   But that's the "American price" which is higher than they quoted a Euro friend of mine.  When I pointed out the discrepancy, R.A.M. stopped talking to me, and I had to buy it through Agostini, which increased the price even more.  Guess that's the Italian way.

Joe

Edit:  This was done before the V7 got popular, and this big bore kit was orig designed for the Nevada, which had a strong following in Europe. 

[Roebling3]

Thanx for sharing, Joe.
Several years ago I was tempted by that kit, hoping raise the power on a Lario. Learning it would be very foolish, all things considered, I took a pass.
Way back I had modified an R-65 to an R-855. It would easily out run any air head (pre bmw wet heads of any type). Sleeved to 100mm bore, major head & intake valve work + dual plugs. Blue printed, too. Top speed was perhaps 112 mph. 6 up on stock! :(   R3~ 

[TN Mark]

I didn't dyno it.  It's on my list of stuff to do (a list that's never completed).  Reportedly big bore kits increase torque, but don't do much for top end horsepower.  This must be esp true on the orig V7, because the small valves of the Heron head limit top end hp (but increase low to mid torque).  On the Files page of this group, there's a bunch of V7 dyno charts, some w big bore kits, some standard.   https://groups.yahoo.com/neo/groups/MG_750/info

The kit was 550 Euro 8 or 9 yrs ago, from the maker, R.A.M.   But that's the "American price" which is higher than they quoted a Euro friend of mine.  When I pointed out the discrepancy, R.A.M. stopped talking to me, and I had to buy it through Agostini, which increased the price even more.  Guess that's the Italian way.

Joe

Edit:  This was done before the V7 got popular, and this big bore kit was orig designed for the Nevada, which had a strong following in Europe.

Fantastic information, thank you.

With the Victory forums I'm on the Big Bore kits are a near constant conversation as they're very popular. The before and after dyno graphs are really interesting when different cams, head work, valve size, throttle body, injector changes and tuning (PCV v Maximus) setups are considered. Many love to show a graph with a high peak number. Of course different dynos record differently and some manipulation of the readings can also be done buy the operator. I always love the high, wide and fairly flat torque curve as well as watching where they start in the rpm range.

Many Victory owners have the same 'low hanging fruit' performance mods that mine has. The difference was simply amazing. But like all performance mods, they quickly become the new normal and then more serious, and expensive, alternatives are readily available. In my case, I'd love to have another 20Hp and 30Ft/Lbs or Torque but not at the dollar figure it would take to get their. In hindsight, the fastest way to a 200Hp/215Ft/Lbs Victory 106 is to add a Supercharger and leave the rest of the 106" engine alone. Bump it up to a 117" Big Bore engine with the supercharger and 240/250 is readily available. Anything above 150/150 and the clutch needs to be upgraded as well. I'm well in the safe zone of about 114/115.     

[Beowulf]

I got to ask. In hindsight do you think bumping up to an 820cc was worth it? Secondly how much should one squirrel away for this modification? Really appreciate you posting this.

[sign216]

I got to ask. In hindsight do you think bumping up to an 820cc was worth it? Secondly how much should one squirrel away for this modification? Really appreciate you posting this.

Beowulf,

I did this because I like wrenching on my machines.  If I had to pay someone else, it wouldn't happen.  Every bike I've owned, I've improved.  Putting on the 820 cylinders was good, but I was unprepared for the fueling adjustment afterwards.  The new ECU took some time to dial in, and was a real time draw. It's hard to tell if I'd do it again.  The torque improvement is a big improvement for me, but the fueling adjustment (and timing too) was no easy road.  But hey, that's why we work on our machines, right?

In short, if you like hot rodding, it's all good.  But if you're going to pay a shop to do it, then buy a bigger bike.

Joe

[Cam3512]

I can just hear Pete Roper’s head exploding into a pink mist.  Doubt he’ll chime in.

[pete roper]

No. If people think it's worth $/€ hundreds to fart about with stuff like this I say 'Go for it'. If though you go to this sort of thing thinking you are going to get some sort of GSX-R slaying monster then you are clearly deranged.

Personally I would of thought that exploring whether the barrels and pistons from a V9 could be adapted to work with the Heron heads would of been a better bet, the RAM kit sounds very 'Bargain Basement/Poverty Pack' to me.

The other thing that really limits performance with the MUIG-3 system is, Ta-Da, the MUIG-3. Its a pretty horrible piece of kit with a tiny choke size. Trying to persuade more air through it and then through the right angle inlet port is an excercise in futility in my book.

YOMV.

Pete

[Beowulf]

No. If people think it's worth $/€ hundreds to fart about with stuff like this I say 'Go for it'. If though you go to this sort of thing thinking you are going to get some sort of GSX-R slaying monster then you are clearly deranged.

Personally I would of thought that exploring whether the barrels and pistons from a V9 could be adapted to work with the Heron heads would of been a better bet, the RAM kit sounds very 'Bargain Basement/Poverty Pack' to me.

Im just curious. How much modification would it take to insert a V9 engine into a v7 ii or iii? Would it be as simple as swapping frame rails to get it to bolt up? Would that be a less complicated approach than swapping cylinders and pistons?

Silly questions i know. As far a gsxr slaying machine im just not interested in that kind of speed. This is just for fun. I don't have any notions of racing.

[Cam3512]

Im just curious. How much modification would it take to insert a V9 engine into a v7 ii or iii? Would it be as simple as swapping frame rails to get it to bolt up? Would that be a less complicated approach than swapping cylinders and pistons?

Silly questions i know. As far a gsxr slaying machine im just not interested in that kind of speed. This is just for fun. I don't have any notions of racing.

Probably easier to put V7 tins on a V9.  Someone on another thread did just that.

[sign216]

Personally I would of thought that exploring whether the barrels and pistons from a V9 could be adapted to work with the Heron heads would of been a better bet, the RAM kit sounds very 'Bargain Basement/Poverty Pack' to me.

Pete

The R.A.M. big bore pistons and cylinders were quality, as good or better than the kits for Harley bikes. 

This is all about making your machine better.  Wrenching for fun.  Like countless people did w Model T trucks back in the day. 

You do it because it's there.

Joe