Post by: stevush on September 22, 2015, 05:52:17 PM
I've just bought a used engine today and taken the barrels to S.E.P in Kegworth for assessment. The verdict ?
I need a rebore "See what you pistons and rings you can get, preferably 0.50, but 0.25 would do".
I see David Silver do oversize piston sets at £48ish. Before I go down that road I just thought I'd ask, does anyone have a set they're willing to part with ?
Thanks
Steve
Post by: Chris400F on September 22, 2015, 08:54:31 PM
Might be worth checking with him to see where he got his parts from.
DS price for four piston kits is the best part of £200 with delivery and VAT, don't know whether you will find cheaper.
Post by: stevush on September 23, 2015, 07:56:05 AM
Yes, looking around last night I've seen a couple of sets all around the £200 mark, anyone got any experience regarding the quality of the pattern parts ?
Steve
Post by: mike the bike on September 23, 2015, 09:44:07 AM
Post by: andut on September 23, 2015, 10:22:49 AM
I got oversize pistons from DS and so far all is well - As Mike says, a big bore kit would potentially be a cheaper option, but I didn't investigate suppliers or quality of kits etc - I didn't want to get involved in rejetting / dyno work that would be likely with cc increase.
Andy
Post by: stevush on September 23, 2015, 04:17:08 PM
Cheers
Steve
Post by: Chris400F on October 11, 2015, 09:51:51 PM
http://www.ebay.co.uk/itm/HONDA-CB400F-CB400-FOUR-F1-F2-PISTON-KITS-0-5mm-NEW-PARTS-P11034-02-377-RiK-/151719631170?hash=item235331d942
They also have +1.00 sets.
Post by: hairygit on October 11, 2015, 09:58:00 PM
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Post by: Chris400F on October 12, 2015, 08:56:34 AM
Think the chances of OEM parts are slim and certainly unlikely at this sort of money.
Post by: royhall on October 12, 2015, 09:14:55 AM
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Post by: stevush on October 12, 2015, 09:25:17 AM
Cruizinimage... I've only seen Big Bore kits from them and that's not what I'm looking for. I emailed them and asked if they had +0.5 pistons and they didn't have any. After recommendations for them I was kinda hoping they'll have a production run shortly and produce what I want.
Regards
Steve
Post by: Chris400F on October 12, 2015, 12:01:30 PM
This quote came from RiderSite.com, from a guy apparently rebuilding a Triumph 6T:
"There are a few sets on eBay, but all the cheaper castings and mediocre rings. I know people who use them, but they don't use their bikes the way I'll be using mine. At £140, they were about £50 more expensive, but that extra buys me the piece of mind that comes with quality components. These two were found on eBay by a company called IMD Pistons. A few others had slipped the net by the time pay-day came around mind, but glad they did."
Thread at http://www.ridersite.ws/rs/viewtopic.php?p=106561&sid=265a6b8cbe278baffbf7b7a4d819a967, quote from page 6.
Yes, Cruzinimage stuff generally seems good but can't buy from there if they don't have the stock, and the big bore kit currently listed on their US site says it doesn't ship to the UK.
Post by: Bodd on October 12, 2015, 05:50:00 PM
Post by: stevush on October 13, 2015, 04:15:41 PM
Cheers
Post by: AshimotoK0 on October 13, 2015, 07:24:41 PM
Well I still have lots to do, the frame is away for powdercoat at the moment and I've not tackled the motor yet so I'm not in any desperate hurry but I'll certainly be keeping an eye on the Cruisinimage site in case the piston set comes up.
Cheers
I reckon they may only offer the big bore kit, as lots of variants to consider as the 400 in japan was just under 400cc and Europe & USA was 408cc.
Ash
Post by: Bodd on October 14, 2015, 06:00:08 AM
I reckon they may only offer the big bore kit, as lots of variants to consider as the 400 in japan was just under 400cc and Europe & USA was 408cc.
Ash
So what size would these (http://www.ebay.co.uk/itm/75-77-Honda-CB400F-Standard-Piston-Rings-Set-4-Rings-Set-Include-CB400FPR-/261954222975?hash=item3cfdb03b7f) standard rings be ?
Post by: Bryanj on October 14, 2015, 06:09:09 AM
Post by: Bodd on October 14, 2015, 08:12:00 AM
"To comply with licence restrictions in France and Japan Honda also produced a 398 cc (24.3 cu in) version by fitting a shorter 48.8 mm (1.92 in) stroke crankshaft."
Post by: stevush on October 14, 2015, 08:36:50 AM
Good question... I'd assume that they're to fit a standard 51mm piston.
I need 51.5 mm pistons and rings, however I do have another option..
I could ask SEP to make and fit new liners, then rebore to std size, then re-use my std Honda pistons with new rings.
Swings and roundabouts really, save on new pistons but pay for new liners ?
Steve
Post by: Bodd on October 14, 2015, 09:07:32 AM
Post by: Trigger on October 14, 2015, 09:12:26 AM
So what size would these standard rings be ?
Good question... I'd assume that they're to fit a standard 51mm piston.
I need 51.5 mm pistons and rings, however I do have another option..
I could ask SEP to make and fit new liners, then rebore to std size, then re-use my std Honda pistons with new rings.
Swings and roundabouts really, save on new pistons but pay for new liners ?
Steve
To have a new set of liners made is not cheap.
Post by: stevush on February 09, 2016, 03:39:20 PM
My bores are STD at the moment but need a .50mm rebore and these pistons slip into the bores now. Surely they should be too large to fit ?
Maybe a stupid question but I'd appreciate some help
Thanks
Steve
Post by: Gixxer-18 on February 09, 2016, 04:41:06 PM
HTH
Nigel.
Post by: stevush on February 09, 2016, 04:46:53 PM
Thanks
Steve
Post by: Johnwebley on February 09, 2016, 05:26:46 PM
I'm ressurecting this thread because I've acquired a set of oversize pistons, or at least I'm led to believe that they're oversize. I have no vernier gauges or the like to measure them but the guy recons they are 51.5mm when he measured them. They are genuine Honda but looking on the crown, I can see no oversize markings anywhere to show the size, are they ALWAYS marked with an oversize ?
My bores are STD at the moment but need a .50mm rebore and these pistons slip into the bores now. Surely they should be too large to fit ?
Maybe a stupid question but I'd appreciate some help
Thanks
Steve
the tolerance on pistons is very close,
those pistons are standard,no other piston would get anywere near ,
Post by: stevush on February 09, 2016, 06:21:36 PM
Thanks
Steve
Post by: Bodd on February 09, 2016, 06:59:20 PM
Post by: stevush on February 09, 2016, 07:16:26 PM
Steve