Dam Pistons!!!

O.K. I’m a newbie here and just like to say Hi and thanks for all the great info on this site!

Now I have been given a 1984 Honda VF1000FE with an RE motor that did a head gasket. I’m now in the process of doing an engine rebuild. The previous owner ordered a set of .5 oversize pistons and rings and Honda in their infinite wisdom sent 3 1000R pistons and 1 superseded 1000F piston. Now I have 3 high comp pistons and one low comp piston. What to do?

I’ve heard mention on here that the CBR1000 of similar vintage runs the same piston…is this true? Are they the same compression ratio of the R model or the F. Does anyone know the exact year CBR1000 to use?

Any help is greatly appreciated…Cheers Wayne

hi wayne,
i may not be much help as ive not had much to do with the “R” model vf’s, to be honest i had always assumed that the pistons were the same between models, i had also heard that the cbr1000f pistons were the same, but i couldn’t verify this myself, compression ratios between different models could be misleading as other things could effect these, such as thinner head gaskets ect.

cmsl has some 0.5mm oversize pistons advertised so you may be able to find the exact one by part number there.
http://www.cmsnl.com/honda-vf1000r-1985-usa_model1118/partslist/E++12.html#results

hope this helps.

Hi Pete,

Thanks for the info, I have actually ordered a piston from CMS after they told me they had the 1984 R model piston in stock, so I ordered it straight away. Now they tell me that they don’t have it but have the 1985 R model piston. Looks the same except for the last 3numbers being 700 instead of 305. Once they have gone the part number supersedes to the F model piston as well so I’m trying to find out the difference between the 1984 and 1985 R model pistons. Anyone have any info?

Cheers Wayne

Sorry, Wayne, I can’t help you… I have 2 “R” one 1984 E model and a 1986 G model which is very different but alas,1985 F models have not been imported in france so no one in the V4H80 w’ll be able to help. Anyway, the 1991 GSXR 1100 pistons are a straight fit once the sleeves have been bored to 79mm… lol

The last three digits may mean big difference: First set of numbers indicate the part (like piston), second set (like MB6) indicates, in which model it was used for the first time, and last three digits indicate the version. Only way is to compare the parts side by side. Googling with part number every now and then may bring results with luck.

would honda uk have any info on why the part numbers were superseded,