[EvokedPotential]

I'm starting to build up a new motor for my G1 track bike. I have gathered a clean core motor (28k, almost all highway commuter miles, great compression), G1 kit intake cam, and a few other items. I tore the motor down yesterday to send the head out for a clean/beadblast/mill/port/rebuild and I noticed a few things.
1. the cam chain is nice and smooth, no kinks, and the adjuster was in the middle of its range. I will replace this chain and add a manual tensioner
2. the cylinders have great hatch but the tops of the bores have darkened areas where the rings change direction. There is no perceptible ridge in this area. Should I be concerned?
3. I will be replacing the oil pickup and the clutch as I noticed quite a bit of fiber/steel sludge in the sump.
4. I will inspect the generator. This is an 04 motor.
Is there anything else I should examine? Should I consider re-ringing the pistons? I did perform a leakdown test on this prior to tear-down and didn't have much on the rings, just on the valve seals which is to be expected at this mileage.

 

[michael4012]

It depends how much money you want to throw at I suppose, what brakes suspension etc? If your looking for a little edge on the other guys with similar machines pick up a set of used 2011 onwards pistons and rods you'll get better compression and less rod stretch meaning you can go tighter on the squish. But make sure there fitted before measure up for the head skim. This is assuming you got a good full system and flash.

 

[gaz]

track bike, .020-025 mill, .45mm hg, good serdi or cnc valve seat recut and that gen 1 cam at 107, ex around 106. porting adds power also, but 2nd to the mill/vj. run 5.50's with this combo including porting. that carbon stain ring at top of cyl no concern, can generally be removed with good solvent on cloth or light scotchbrite pad. no need to rering. like the way ur build looking-clean, but would'nt bead blast the head, glass particles get in oil galleys, embed in all the blasted aluminium but release with oil and heat. degreed gen 1 race int several different lc's, these numbers made best hp, torque. who's doing mill/porting vj?

 

[EvokedPotential]

Head work is being done at competition CNC.
I pulled the generator out, it appears it was starting to run out judging by the paint wear and the "machining" on the case at the rotor shaft area. This confirms that the motor was used as a commuter or someone applied the update early in its life.

 

[EvokedPotential]

 

[gaz]

jim at competition cnc does good work, will run well.

 

[EvokedPotential]

track bike, .020-025 mill, .45mm hg, good serdi or cnc valve seat recut and that gen 1 cam at 107, ex around 106. porting adds power also, but 2nd to the mill/vj. run 5.50's with this combo including porting. that carbon stain ring at top of cyl no concern, can generally be removed with good solvent on cloth or light scotchbrite pad. no need to rering. like the way ur build looking-clean, but would'nt bead blast the head, glass particles get in oil galleys, embed in all the blasted aluminium but release with oil and heat. degreed gen 1 race int several different lc's, these numbers made best hp, torque. who's doing mill/porting vj?

I'm not sure how he is removing the paint (vapor, chemical stripped, etc) but it will be returning raw. Luckily I live in the high desert so I'm not concerned with corrosion/oxidation. This should be a big boost over the stock, tired motor coming out.

 

[EvokedPotential]

It depends how much money you want to throw at I suppose, what brakes suspension etc? If your looking for a little edge on the other guys with similar machines pick up a set of used 2011 onwards pistons and rods you'll get better compression and less rod stretch meaning you can go tighter on the squish. But make sure there fitted before measure up for the head skim. This is assuming you got a good full system and flash.

I have full ohlins/brembo/akrapovic/PCV-IGN-AT/BST/etc. I'd rather not split the cases since I hear the transmission is a PITA to deal with but I will consider it if you think it's worth effort. From my understanding going big-bore doesn't really add much power over the increase in compression and porting.

 

[thundercoupe9]

I would split cases and inspect everything before putting it back together, I'd replace the rings at very least and bearings if they're worn. Otherwise you throw a good head on it and a week later it throws a rod undoing all the work that you have done. Splitting engine is not that hard, you can use service manual and there are videos and write ups too.

 

[michael4012]

I agree with thundercoupe 100% your spending a lot of money on the bike suspension brakes etc your investing in a head for performance but the most likely place your going to lose power is through those rings, at very least check there gaps are in service, but ideally fit new to the tightest tolerance. Your also going to raise the rpm limit I expect to match the cam dialing, so bearings are going to be tortured so to speak, yes new bearings add up extra cost but at least inspect them and check tolerance. You can also boost the oil pressure releive valve while your there. The gearbox it would be a bummer if that has dodgy dogs and you start missing gears with that lovely new build. Yes so even just to inspect and check tolerances it's worth the extra time and effort. Fitting G4 pistons and rods will increase the compression and I have got engines at 14000 with 0.55mm squish. It will give you an extra top 3 hp but the middle range torque is up 5flb.

 

[EvokedPotential]

Ok, I'll crack her open and source those G4 parts. Im curious which HG options I should assemble if the crown heights are taller on the newer pistons. I have .45, .50, and .55.

 

[michael4012]

Those G4 pistons are really tight at 3 & 9 O'clock, on G3 head i have used 0.45mm gaskets and had 0.6mm skim, which gave me 0.55mm squish at thise 2 tight points, I expect the G1 head will need a little more skim as the pentroof is bigger on G1 & 2, But you have to be very methodical on the measure up use solder wire I find it more accurate. Use the con rod bolts that are already in the rods for sizing up your shell bearings and fit new bolts for final assemble. Ring gaps your safe to go for the tightest gap The G4 manual gap not G1 remember.

 

[EvokedPotential]

Those G4 pistons are really tight at 3 & 9 O'clock, on G3 head i have used 0.45mm gaskets and had 0.6mm skim, which gave me 0.55mm squish at thise 2 tight points, I expect the G1 head will need a little more skim as the pentroof is bigger on G1 & 2, But you have to be very methodical on the measure up use solder wire I find it more accurate. Use the con rod bolts that are already in the rods for sizing up your shell bearings and fit new bolts for final assemble. Ring gaps your safe to go for the tightest gap The G4 manual gap not G1 remember.

hrm, well I already sent the head out, not sure if Jim is working on it yet due to the hurricane that just passed by. I specified 0.5mm mill. I'll see about pushing to 0.6 but at this point measuring using the current motor in the bike's head is my only option after the last TD of the season next weekend. I will try to find some OEM rods but I will also consider other options as well as having this crank balanced/knife-edged/etc. Thanks for posting that vid, I have a lot of confidence now is disassembling and inspecting the trans. I've been running a quickshifter for two seasons now and I'm sure the trans in the other motor is pretty beat up by now. Hopefully this trans has been babied.

 

[EvokedPotential]

I got a great deal from a local vendor on a NOS set of wiseco 13.5:1 pistons. I'll have the cylinders deglazed and the new slugs mic'd/matched and balanced. I'm going to split the cases tonight and get the crank sent out for knife-edge/lighten/balance.

 

[michael4012]

They can get good weight of those G1 cranks 1.7kg, it makes her spin so much quicker. What rods are you going to use? Im not sure What squish is safe with the G1 rods, I hope somebody else can chime in.

 

[EvokedPotential]

They can get good weight of those G1 cranks 1.7kg, it makes her spin so much quicker. What rods are you going to use? Im not sure What squish is safe with the G1 rods, I hope somebody else can chime in.

Still looking around for a deal, but most likely Carillo. They're 50g lighter each than stock and quite a bit stronger.

The knife-edge crank and balancing should pay dividends when it's spinning to 13.5k.

 

[thundercoupe9]

Still looking around for a deal, but most likely Carillo. They're 50g lighter each than stock and quite a bit stronger.

The knife-edge crank and balancing should pay dividends when it's spinning to 13.5k.

Carrillo rods are not 50g lighter than stock gen1 rods.

 

[EvokedPotential]

Carrillo rods are not 50g lighter than stock gen1 rods.

Yeah I can't seem to find a reliable number, I've seen 50g in a few spots.

 

[michael4012]

The G4 rods are 25g heavier than the G1 rods but they have more material where needed which means they stretch less so you still benefit power wise, and of course the rods them selves don't fail. Carrilo rods are expensive I thought you were trying to keep costs down? I have a set of the maxspeeding rods for G1 unused still in box, with new unused size 'black' shells, iv cut a notch in the top as carillo rods for extra oil feed. I had bought them for a stroker motor but they won't fit without cutting the cases so there surpless you can have them with the shell bearings for $400 + shipping if you want.

 

[thundercoupe9]

Yeah I can't seem to find a reliable number, I've seen 50g in a few spots.

zx10r rod getting weighted along with carrillo.