Have you a 853 Bigbore Kit Fitted? (This May Worry You!)

egypt220 · 10 Apr 08, 04:12 PM

i have a 748s big bore that i bought from a well known ducati shop,my mate who builds bike all day long was doing my bike today,
striped it down put the new pistons on slip on the new barrel and there was no hole for the dowl so he phones me and says we have a problem with your kit ?
what i say it the wrong one,no its not i said stop pulling my leg,yes it is as the is no hole locatting dowl as there are 2 and one is in the right place but the other is not.

ok let me phone the shop.

phone the shop the and the guy behind the counter was as good as gold looked everything up for me and phoned me back saying yes you have the right kit.

phone my mate it the the right kit,give me the number and i will talk to them,so i said no i will get them to ring you as if my mate says there is a problem there is a problem.

anyway the head technician tell my mate we have fitted 100's of these kits you just take the dowl out and throw it away ??? what he says but it there to line the barrel up as it could be out off line.

dont worry the technician say when you tighten it all up it lines up.

my mate says i like to build an engine properlly.

im going to talk to the manager tomorrow as this is not what i call top workmanship.

if they built your bike like this you would never know as they would not tell you,and if you have a problem down the line like a valve hitting a piston,i bet you would get blamed or they would say sorry thats just ducati's.
and then you would get charged again for a rebuild.

as i dont really want my engine to go bang as it could mean that the valve could be 10 degree's out of line with its grove in the piston.

im going to see what happens tomorrow as i want a hole for the dowl to locate into and i will have to go to an engerneering firm to do it as i would not trust them to do it before building the engine up.

if i have no joy im going to get the trading standards involved,and even the fsa as this is wrong.

update tomorrow.

ray998 · 10 Apr 08, 05:23 PM

give rich at louigi motos a ring 01761 453366 for advice he has done loads of this type of work and is a proper expert

egypt220 · 11 Apr 08, 07:50 AM

cheers will do went tho look at the barrels after work as my mate wanted me to see what the problem was on the standard barrels there is only 1 locating dowl which is ok as its a locating point so when you put the 4 bolts in to thighten down the head and barrels it hold the barrels in place.

on the bigbore barrels there is no locating hole for the dowl so how can a top ducati technician tell to build up the engine and just use the 4 bolts as locators,as the bolts are not the same thickness as the hole hole so if it is built slightly off center that means the piston will still be in the right place but the valves will be out of line.

it may only happen 1 in every 20 or so but where do you think i would stand if the valve hit the piston ?

Rob998 · 11 Apr 08, 07:56 AM

Originally Posted by egypt220

it may only happen 1 in every 20 or so but where do you think i would stand if the valve hit the piston ?

At the side of the road, cursing the day that you thought that the big bore kit was a good idea!

egypt220 · 11 Apr 08, 08:16 AM

thats just what i was thinking yesterday,so im going to ask for my £950 back plus gaskets for the new rebuild.

Ghost · 11 Apr 08, 08:23 AM

As the motor is already stripped, Could you not get a local machine shop to bore the dowel hole??

egypt220 · 11 Apr 08, 08:34 AM

i could and proberlly will,but it's not the point.
you have to find a really good machine shop as it has to be spot on or it will be in the wrong place.
we have said this to the shop in question yesterday and the will not pay for the hole to be done in a machine shop.
as the would like to build it up themself's oh really like im going to let you just throw away the dowl and build it up.
as if it goes bang you will just say it something i had done like over revved it.

Ghost · 11 Apr 08, 08:49 AM

I agree entirely the head can move in relation to the barrel a significant amount, ideally it should have 2 diagonally opposed ring dowels.

Hope you get it sorted to your advantage.

matt#corse · 11 Apr 08, 10:42 AM

Hmmm worrying stuff this

Ive got a Bucci hi comp piston and cylinder kit for my 916SPS ,i will have to look into this before it gets fitted.Surely they should all have diagonally opposed ring dowels as ghost and yourself has stated.

Sounds like poor stuff to me and i dont blame you for not letting them build your engine if thats the way they go about it.

I dont know how there allowed to sell this stuff if its not fit for purpose.

Ill try and post some pics of my bucci kit as im a mechanical numpty so hopefuly some of you in the know can give me some advise.

Worrying thing is i just spoke to a guy of this forum that has just done the same 853 mod.Hs loving it but i doubt hed be pleased if the engine s##t itself when out for a blast.

Dan · 11 Apr 08, 10:53 AM

It'll be interesting to know what 853 kit you've bought because I've heard that there are a number of companies that supply them, so I wonder if they all only have one locating dowel, or if some come with two as desired?

nelly · 11 Apr 08, 11:33 AM

I've seen this once before. Machined the hole in the cylinder and away it went.
There are two cylinders, depending upon year/model. It's the dowel position that moves though, not deleted. If you have cylinders with the dowel hole in a different position, you'd have a similar problem.
The two holes, in the cylinders, are because they are universal, front or rear. You turn one around to suit.

I think it may happen because they are "virgin" cylinders, and the dowel hole hasn't been machined??? The kits I've had done, or had supplied, have used rebored 748 pots so the holes have been there. You still need to look out for the dowel position though.

egypt220 · 11 Apr 08, 09:24 PM

Originally Posted by Dan

It'll be interesting to know what 853 kit you've bought because I've heard that there are a number of companies that supply them, so I wonder if they all only have one locating dowel, or if some come with two as desired?

i believe it's a v2 kit the kit is top stuff apart from this dowel bit,as im now going to have it drilled.

egypt220 · 11 Apr 08, 09:28 PM

Originally Posted by nelly

I've seen this once before. Machined the hole in the cylinder and away it went.
There are two cylinders, depending upon year/model. It's the dowel position that moves though, not deleted. If you have cylinders with the dowel hole in a different position, you'd have a similar problem.
The two holes, in the cylinders, are because they are universal, front or rear. You turn one around to suit.

I think it may happen because they are "virgin" cylinders, and the dowel hole hasn't been machined??? The kits I've had done, or had supplied, have used rebored 748 pots so the holes have been there. You still need to look out for the dowel position though.

its a late 748s 2002,i believe its the same as the first 749.it only has 1 dowel on each cyclinder at the rear i think as the barrels were off when i looked.

egypt220 · 11 Apr 08, 09:33 PM

i spoke to the shop today they just say we have done hundreds of them and never had a problem,im going to just get the hole drilled and have a piece of mind.

im not happy the way they will just build it like this but they seem to know better than me anyway it will all hopefully be ready next week.

egypt220 · 14 Apr 08, 05:14 PM

im glad to say my friend went up and had the dowel holes drilled on friday for me and he has just phoned me with a 853s ticking over in the back ground.

now all i have to do is run it in then take it back and have the head re-tourqed down and the belts tightened and change the oil maybe then its off to germany in june.

cant wait till its got a 1000 miles on it so i can see how it really goes.

i must say he is still one of the best spanner men i know,and a good mate at that.

he is based in kings x if any of you need a good service done.