This post starts at three different locations with three different forum members, apologies for it being posted in general but i feel this needs to be seen by all. As said, three of us were rebuilding two valve engines, all circa 1995. the barrels were all sent off to the replaters at different intervals for replating, all engines were built. SPR Racing got a call from one said member to be asked to comment on the condition of one of these engines, they called me and asked me to comment knowing i have recently had barrels replated. What i found can only be described as utter devastation, everything was worn out, it looked like it had been to the moon and back. This had me thinking and asking questions, my own motor? was it ok? best thing was to drop the front head off and have a look, short answer NO! The other part of the trio came in on this when i told him to check his own, result: lack of compression on the third motor! All these as said being replated at the same place. Since then all have been replated, i dont know about the others but mine came with a bill and a statement that it was not their fault, i cleaned everything 2 or 3 times and re assembled the engine, after 20 mins running in using the dyno i dropped the oil and had a look in the filter (metal screen type), the filter was full of glass bead AGAIN! I checked the barrels with an endoscope and clear evidence of scuffing and contamination can be seen after just 20 mins running. luckily the other two have not yet run their engines. I have now changed the oil about six times to try and get rid of this contamination, i think it has mostly got rid of, the motor does want stripping but i need to run the motor to get the ign and carbs set up before i take it to bits again. interestingly both bikes that were still running were producing good power on the dyno in spite of the issues happening inside. It seems that the replaters blast the barrels before working on them to clean them, i found that the blast media seems to bury itself in the aluminium such that no amount of cleaning will dislodge it, it then comes out of the ally when it gets really hot, the places i found this are on the spiggot and inside the triangular oilway on the side of these particular barrels. I am not prepared for legal reasons ( thinking of recent events) to say where these were done, The company in question has stated to me again that it it not their fault it is someting i am doing wrong, my statement here is that i am a fully qualified motor / motorcycle engineer with over 30 years experience, so i think not. My advice is do not take your barrels or any engine parts to a blaster, unless using soda, even walnut can give rise to problems. and do not use any replater that states that they will BEAD BLAST your barrels to clean them. I openly admit it was my mistake as i should have read the website of the company doing the job, COSTLY MISTAKE! I also am not prepared to divulge who the other forum members are, if they wish to come forwards with their side of the story they will. Finally, A big "THANKYOU" TO SPR Racing in nottingham for all their help with this and the constant use of the dyno to try and run the bike to wash this crap through, I am now a big fan of washable oil filters. YOU HAVE BEEN WARNED.
Sorry to hear about your problems. The below confirms what you have been seeing. I took this from a company that understands how to clean an engine. "Vapour blast cleaning of a casting may cause glass media to impregnate the internal surface. Under the influence of engine harmonics, heat and pressure the shards release from the casting into the engines oil."
Something i was fully aware of, as should the platers, Quote from them "we do thousands of these and never have a problem". As i said, my mistake for not reading the web site. thanks anyway.
Sorry to hear your troubles really does not sound good, I have had many sets of barrels done and always use Langcourt never had an issue with any work they have done Home
As the 'third man' in this trio, I feel I should comment on my experience. Some of you will know that I have built a Monster, basically from scratch. This took me the best part of 3 years and the build included a 2mm overbore/replate (up from 904 to 944cc) and so the barrels were duly bored and plated. I then completely rebuilt the engine with new pistons, bearings, seals, crank balance and many 'special' parts, absolutely no expense was spared (money-pit) in this but I was happy with the end result. The bike made good power and ran very well, however it was always using a lot of oil and this didn't improve after running-in, so this winter I stripped the top-end only to find significant bore-wear after only around 2,000 miles running. I don't know exactly why this occurred (although I have some suspicions) but it certainly wasn't because the engine wasn't built properly, so I contacted the replater and after some discussion it was agreed that they would re-plate them. So as with the OP I forked out more money to have them plated again plus buying new piston rings and the (not-insignificant) time taken to do the rebuild, something I'm not particularly happy about but have had to accept. I now have the engine fitted in the finished bike and, although I've not run it yet, it is ready to go - or is it? I washed the barrels thoroughly both with soapy water and with paraffin in the wash tank to get out any crap that may have been in them (specifically the oil ways). Satisfied that they were clean I repainted them, which involved VHT paint and cooking for an hour and a half in the oven at 200 degrees - I didn't notice any beads/media but then I wasn't looking for it either. Now, after hearing the OP's story I'm in a "do I, don't I run it" quandary. I really don't want to strip the engine again to check/clean it but I don't want to run it and bugger it up either and with the prospect of decent weather at the weekend I was half-planning to start the run-in procedure. So what to do now?
Tim, Thanks for your input, you really are in a "do you - don't you situation", Bootsam's input needs to be taken seriously as does a comment i just had from one of my engineers, he said that when skimming heads that have been blasted you can hear the media as the cutter does its sweep, result is bad cutter wear! Kato said "Sorry to hear your troubles really does not sound good, I have had many sets of barrels done and always use Langcourt never had an issue with any work they have done Home" As for other comments, thanks for the sympathy but i have had barrels done before with no issues but i wont be using the same company again.
I have vapour blasted engines and internals you dont have the problems that you do with bead blasting,the media just washes off with water.
Sounds like they have you over a barrel (sorry :biggrin These guys know about cleaning components I Cleenz Macheenz! | Welcome to our site
