More barrel questions.

[andyroach]

Does anyone know if the 350 barrels are all iron and can be bored to 500, so I can buy some pistons and fit them to the 501 bottom end?
Cheers
Andy

[SupermotoDave]

No.

David

[andyroach]

Is that no, you don't know or no you can't bore the 350 barrels to 500 or the 350 barrels don't fit in the 500 cases or are the barrels not iron and can't be bored at all?
Andy

[morinipete]

No, you can't bore them out. They will take 500 liners but if you're going this far it would be cheaper to buy some 500 barrels. You'd also have to make up some compression plates to go under the 350 barrels as they're much shortr than 500 barrels.

Pete

[andyroach]

Thanks Pete,
Have you had any experience of the 450cc big bore kits being sold on the continent? theoreticly they should make the engine rev better than with the longer throw 500 crank, but i would rather find out what they are like before spending a wad of cash on one.
Cheers
Andy

[EVguru]

Fridegotto had 500 pistons made with a smaller gudgeon pin to suit the 350 rod, but I don't know if they needed new liners. http://www.morinispecial.it/motociclism ... egotto.pdf

The 350 barrels are two fins shorter than the 500 so you can't run the 500 stroke. The liner skirt might not be long enough if you ran a spacer. The big bore kits for the 350 (and I've seen a 520 conversion) mostly use a flat top piston and then don't let it come to the top of the bore to leave a combustion chamber. Given how important the combustion chamber shape is meant to be for mid range torque, I'd worry that such a crude chamber shape wouldn't work that well.

In any case, barrels aren't the biggest problem. You're going to need bigger valves to fill the bigger cylinders and there's not much room in a 350 head. People did once move the valve guides apart and modify the rocker gear, but really you need 500 or 501 heads and the latter have a bit of a reputation for cracking between the seats.

A 501 bottom end with the timing side converted to a roller bearing is meant to be good for 10,000 rpm plus.

350 and 500 barrels have the same size spigot, but I think the 501 barrels use a larger one.

[andyroach]

I have a complete 501 motor, but as I have said in another post, it will push me in to the unlimited class and i will be up against 900 hondas, 1000cc BMW's with tuned motors etc and in this company(with this rider) I don't think I will be competative. I had thought about doing something with the 501 barrels, but they are nicosil and again it looks like it's going to be a lot of hassle/cash. I think I need to go back to the original idea of getting hold of some 500n barrels for the 501 motor.
If anyone has said 500 barrels and pistons that they would like to part with they can PM me.
thanks evguru for the insight.
Andy

[John Bunting]

Hi Andy,
Are you looking for a buyer for the 501 engine??
Regards
John

[andyroach]

Hi John,
I don't want to sell my 501 motor, but I may be able to supply you with a 501 motor if you really want one.
There is a chap I know who may sell one of his motors that he doesn't have a bike for(he has around 50 morini's).
P.M me and I will contact him. Also I will need to know if you want a running engine or one in bit's etc.
Out of interest how much does one of these motors go for?
Cheers
Andy

[George 350]

Hi Andy,

Something you might not have considered (and I have no idea how Morini cranks would cope with it, nor where you would get it done in Spain) is to get your crank built up by metal spraying and have the big end journal reground to give a slightly shorter stroke - something as little as 0.5mm stroke reduction ought to be enough to get you under the 500cc limit. It is a well recognised method of modifying cranks in the motorsport industry. You may need to fit thinner base gaskets to the barrels as you will obviously lose a small amount of compression. Just thinking it might be easier than trying to find special pistons/barrels?
George

[John Bunting]

Hi John,
I don't want to sell my 501 motor, but I may be able to supply you with a 501 motor if you really want one.
There is a chap I know who may sell one of his motors that he doesn't have a bike for(he has around 50 morini's).
P.M me and I will contact him. Also I will need to know if you want a running engine or one in bit's etc.
Out of interest how much does one of these motors go for?
Cheers
Andy

Hi Andy,
I have an 81 500sei, I rebuilt 478 engine of this bike with all rotating and reciprocating bits lightened plus offset rockers to increase valve lift, now I would like to go a bit further
I have been on the lookout for a 501 engine for more than a year with the plan to rebuild it with roller bearing crank and a new2+2 cam which I bought in Italy.
I don’t know the value but recently bought a Gilera Nordwest engine for £150 as a spare for my Nordie and RC600, “bikes are a sickness”
An engine in bits would be ideal as I’m going to strip it no matter what its condition
Regards
John

[andyroach]

Hi John,
spoke to Alejandro this morning and he doesn't want to sell any engine parts, especially 501, as he is going racing next year and suspects he will need all the engines he can get.
I don't know where you are in the world, but there is a 501 excalibur for sale in northern Spain(I live in the south) and it is advertised for 700 euros complete.
PM me off line If you are interested in me ringing the chap for you(unless you speak Spanish) and find out the condition etc.
Regards
Andy

[John Bunting]

Hi John,
spoke to Alejandro this morning and he doesn't want to sell any engine parts, especially 501, as he is going racing next year and suspects he will need all the engines he can get.
I don't know where you are in the world, but there is a 501 excalibur for sale in northern Spain(I live in the south) and it is advertised for 700 euros complete.
PM me off line If you are interested in me ringing the chap for you(unless you speak Spanish) and find out the condition etc.
Regards
Andy

Hi Andy,
I'm a long way from Spain and most other places in northern Nigeria, thanks for trying with Alejandro, I don't think I want a complete Excalibur, the cost of shipping is quite high without the cost of buying a bike just for an engine.
I will be patient a little longer.
Thanks for your help
John

[Jem]

Andy,

a friend has asked me to post the following. He has spent time in the past tuning 478/501 motors.

"The 507 barrels are a larger diameter on the spigot and therefore the holes in the crankcase are larger. If he fits 478 barrels they will drop in but won't have the integrity or rigidity as the barrels will be a sloppy fit. When I fitted 507 barrels to a 478 crankcase I had to turn a 2mm (I think) off the spigot diameter. He needs therefore 478 crankcases and to fit 70mm pistons which will bring him up to 496cc just under the 500 limit.

If he intends to race, then he should use forged pistons not the Morini ones with the split skirts as the skirt where the hole ends the split has a tendency to crack and break off. I have rebuilt a number of engines which when on stripping have had this problem either a crack propagating to the edge or the bottom already broken off. The pistons I had made some time ago were forged because at the time Asso only had one piston with no intention of making anymore."

He was offering a 500 which had been worked on, a couple of months ago. I'll ask if it's still available.

Jem

[andyroach]

Thanks for that Jem,
If you could PM me with your friends email or give him my email I would be interested in talking to him about the motor he has for sale. If the motor is no longer available I would be interested in talking about tuning work on the motor, as I have had conflicting opinions about cams and various things like the use of air filters or cone filters and it would be nice to talk to some one who has actually raced one of these.
Cheers
Andy