RB20 fitment issues.

[Muppet]

suspense is killin me,

[10 inch Terror]

Ok, I think I've sussed it. I've removed the excess stud thread at the crank case. I've also discovered that the base gasket I made was slightly too big and was pinching between the spigot and crank mouth.
With the gasket trimmed and the thread removed the barrel now slides all the way down by hand a with just a very gentle final push it goes all the way home. There is still a very slight resistance but it's 100% better than before. I think it will now be ok as it is. Thanks for all your comments and input fellas.
Pete.

[Adam_Winstone]

^... glad to help. Well done for sticking with it and resolving the problem.

Adam

[warts]

Hope its all hunky dory now.

Other than possibly voiding any warranty, is there a reason not to just slightly relieve the lower cm in the barrel?

[10 inch Terror]

Hope its all hunky dory now.

Other than possibly voiding any warranty, is there a reason not to just slightly relieve the lower cm in the barrel?

I did think of doing that and if it was still tight this time, I would of done it. I'm happy with the way it fits now, so I'll leave it as is.

[ducksta]

glad you sorted m8, would of been wise to mention the home made gasket earlier as it might of speeded this thread up for you the more info the better.

[Adam_Winstone]

Please note, this was never up for debate as it is an issue as old as the hills. Although I have not played with an RB20, I was sure that changing to standard shaft diameter studs would resolve the issue, as it does on so many other rebuilds (ranging from factory standard iron top ends to all sorts of kits from a range of producers). The first time that 'fat' studs caused me my motor build (factory barrel on Innocenti 200 casing) was about 1990 and is something that others have been suffering (or ignoring) ever since!

Please note that this was not a thread aimed at any specific dealers' product but it became perceived as a dig at MB (not my intention) as they sell oversized stud kits. Whilst I appreciate those that have contacted me on here by PM, via email and on FB, saying that they have had exactly the same problems with fat studs, PLEASE can you give this feedback to those that are supplying them?! Unless you do so, the problems will continue and nothing will be done about it. Indeed, one of these contacts was from a guy that has just stripped and rebuilt a motor, only to find that he can no longer fit the same iron barrel back to the same casing because of the 'fat' studs that he bought as part of his rebuild order... and THIS THREAD made him aware of the problem (replacing the original studs has resolved his assembly problem too). This is not the fault of the barrel or the casing!

Hopefully, we've resolved the issue, highlighted a potential/common problem (noting that plenty of engines will not have any issue with fat studs, plenty of others will), helped others to avoid this same issue in the future, and it may even result in dealers getting the feedback they need so that they can improve on their current offerings.

As far as MB is concerned, they are still up there with the very best dealers, products and service available.

Cheers to you all.

Adam

[jason frost]

I use the MB studs and they have always worked for me, but I can see what you are on about Looking at the MB stud the end that goes into the casting is short, 15mm or so and is stopped by the step of the fat bit from going in anymore, when a rolled stud is used it would just keep on going, 25mm I think on a full retapped M8 with a number 3 tap, this would then leave the top of the studs uneven to use the longer nuts that seem to work better than 1/2 nuts. Need to have alook at this some more as I say its not something that I have come across.

[soosh]

Adam,you have probably solved a lot of issues that people have had over the years but they just put it down to just "one of those things" or a bad barrel.

[slangen]

Best thread ever, thanks to all involved you made my day!