New Rotrex C38-91 Supercharger

Oh dear , I feel sick

Neville Lush said:

I have seen the weeny bearing which is now going in that cover. I had one sent out by mistake. If it was me ( and it is not) I would machine the cover to accept TWO of the ball bearings as with only one there is opportunity for the shaft to flex around the ball bearing If I have described that properly. There is a lot of pressure on that part, belt tension needed to drive the blower at 95000rpm etc. The needle roller should be the best really, the *****it runs on should be harder and maybe a small oil feed to the rollers. As far as teardowns, I do not know about that. There are not many blown bikes about here, but each one I have seen has had piston damage from poor tune etc. So they have to come apart anyway. We have a large country where folk can hold the bike at high speed for a fair while, showing problems which don't occur in a 4 second dyno run.

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Yes I was suprised at the size of the bearing myself and plan on looking for a thicker one that is grease paked and sealed like Triump did withthe rear final drive. I do not think I get as much stress down there as the other supercharger guys because I went with a larger pulley on the blower which makes for less stress driving the planetary. I am darn close to a one to one ratio between the crank and the blower I have a 95 mm pulley on the bower which I figured what I lose in boost I make up with thee 11.8:1 compression pistons. The real qusestion is can I find such a bearing I do not mind going with a larger diameter and boring the case because I truly love the added pep using both kits together. It is just plane insane when I turn her on hard. It has so much power I do not care about HP numbers just good A/F ratios and correct timing. You can tell she is strong when you bang fifth gear at 179 mph. So true ower number is not important to me.
Peter you have nothing to worry about you have benn in your before and have had it so long if you wer to have a problem you would have noticed it. besides my bet is the ones Nev is referring to as have piston problems were most likely running just the base tune or the tune with just some percentage of fuel added. Niether one fits your case. Also timing is a factor as the base tune is a wee bit off. I found the fact that gas stations cannot be trusted and fuels can be so different I alkways carry octane booster and add just enough to raise the octane of the amount of gallans I am adding a coule pointsjust incase. In fact I carry a quuart in my hard bag so I can always rely on it being in a good area. Ist a small area to give up in my bag. infact latley I have been thinking about adding a extra over flow bottle with a pitcock valve on the bottom so I only have to carry a little bottel in my bags. A four ounce baby food bottle does the trick as I usually end up adding about 4 gallons a fill up anyway. Tis should be carried over to the Tech site. There is only one guy I know of with a TTS kit on these sites that is not a member yet. That is unforgiven and he can remedy that if he chooses by sending me a PM with his e-mail address and I will take care of the rest.

Pedro

You will be alright, you have had a decent tune. Warp, if you machine your cover and put two of the ball bearings in that will be a good mod.

Neville Lush said:

You will be alright, you have had a decent tune. Warp, if you machine your cover and put two of the ball bearings in that will be a good mod.

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Thanks Nev I will look at it but I do not remember if there was enough material left at the bottom to bore it deaper and have room for the seal. Thats why I was think one thicker sealed bearing. But I will look at it when I take her apart. Just waiting on new style head studs instead of bolts. I believe the Triumph bolts are a little on the week side. But of course that is just my opinion and I am by no means an expert on bolt stretch calculations. I know I do order a new set of bolts everytime I take her apart. Have you ever re-used them before?

warp9.9 said:

Thanks Nev I will look at it but I do not remember if there was enough material left at the bottom to bore it deaper and have room for the seal. Thats why I was think one thicker sealed bearing. But I will look at it when I take her apart. Just waiting on new style head studs instead of bolts. I believe the Triumph bolts are a little on the week side. But of course that is just my opinion and I am by no means an expert on bolt stretch calculations. I know I do order a new set of bolts everytime I take her apart. Have you ever re-used them before?

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WOT new style head studs????????????????????

ruzzle said:

WOT new style head studs????????????????????

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that would be Art !! ha!

ruzzle said:

WOT new style head studs????????????????????

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Yes Ruzzle trying to get something sorted out I will let you know if it ever comes thru.

I did away with the stretch bolts some time ago, in favour of big chunky bolts lots of room for bigger & longer in there .

Les - So how do the non-stretch bolts handle the different expansion rates of the bolts and the head, and maintain pressure on the gasket????

ruzzle said:

Les - So how do the non-stretch bolts handle the different expansion rates of the bolts and the head, and maintain pressure on the gasket????

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Ya got me thinking Ruzzle. If we are concerned about expanding from thermo coeficient of expasion then we would certainly have the same problems with the OEM stretch bolts.

We torque the stretch bolts and then turn then 1/4 turn more more after torquing them to 50 NM at this point the bolt stretches. The question is does the bolt just stretch or does it have elasticity to return to original setting after several heat cycles. If so I would say all bolts have some sort of elasticity not to mention the expansion of the block and head. which brings me back to the original question does the OEM bolts return and if so, why do they have to be replaced everytime the head comes off? (according to the manual)