iainb 4,962 Posted May 3, 2022 I've noticed over the last few years that a number of the top riders in the GP have parts of their engine cases coloured black, Jason Doyle (I think) was riding a snazzy looking humbug at the weekend with a black middle part. My question is are there performance parts or just decorative? It just used to be GM badge that was coloured, red, blue, green etc. again was that just decoration or performance related? TIA Share this post Link to post Share on other sites
steve roberts 9,242 Posted May 3, 2022 Recall that Ken McKinlay used to have a white engine cover! 1 Share this post Link to post Share on other sites
iainb 4,962 Posted May 3, 2022 14 minutes ago, steve roberts said: Recall that Ken McKinlay used to have a white engine cover! Really? Paint, i wonder? I've never seen that Share this post Link to post Share on other sites
SPEEDY69 1,247 Posted May 3, 2022 4 hours ago, iainb said: I've noticed over the last few years that a number of the top riders in the GP have parts of their engine cases coloured black, Jason Doyle (I think) was riding a snazzy looking humbug at the weekend with a black middle part. My question is are there performance parts or just decorative? It just used to be GM badge that was coloured, red, blue, green etc. again was that just decoration or performance related? TIA Decorative only. Some tuners will go for a look for their brand or a rider may want to distinguish between engines. 1 1 Share this post Link to post Share on other sites
rcgods 4 Posted May 3, 2022 Timing covers can be swapped from the standard cast items to bling CNC aluminium ones, maybe better heat dispersion. Some are also vented. The main part the riders have different between engines is either is on the head covering the cam end. These "badges" are available from GM in 3 or 4 colours and there are also bling aftermarket ones with fins etc. Bjerre engines have their own CNC milled ones with Bjerre Motorsport engraved on them (or they did when we had some of their Jawas). This is easiest to spot from the stands. Some riders also have names for engines usually engraved on the timing cases or they refer to them by the tuner serial numbers. 2 1 Share this post Link to post Share on other sites
iainb 4,962 Posted May 3, 2022 43 minutes ago, rcgods said: Timing covers can be swapped from the standard cast items to bling CNC aluminium ones, maybe better heat dispersion. Some are also vented. The main part the riders have different between engines is either is on the head covering the cam end. These "badges" are available from GM in 3 or 4 colours and there are also bling aftermarket ones with fins etc. Bjerre engines have their own CNC milled ones with Bjerre Motorsport engraved on them (or they did when we had some of their Jawas). This is easiest to spot from the stands. Some riders also have names for engines usually engraved on the timing cases or they refer to them by the tuner serial numbers. Thanks, very interesting Share this post Link to post Share on other sites
steve roberts 9,242 Posted May 4, 2022 9 hours ago, iainb said: Really? Paint, i wonder? I've never seen that If I remember it was an actual cover that he placed over part of the engine? 1 Share this post Link to post Share on other sites
OveFundinFan 4,137 Posted May 4, 2022 1 hour ago, steve roberts said: If I remember it was an actual cover that he placed over part of the engine? Some riders used an engine cover on the right side of the engine to protect the left leg from engine heat burns. Is that what you referring to.? For grass tracking I used motox leather trousers and they had a burn mark just abut the inside knee area. 1 Share this post Link to post Share on other sites
*JJ 508 Posted May 4, 2022 The black parts are probably made from magnesium, instead of aluminium, to save weight. we had an engine which had not only the cam cover and timing cover in magnesium, but also the main timing case. Whe we bought it, we did not appreciate that the engine was actually an Ashtech job! Share this post Link to post Share on other sites
Ray Stadia 1,064 Posted May 4, 2022 I remember an engine tuner, possibly Trevor Hedge, used to grind off the 'W' from a Weslake rocker cover and spray the cover black! Share this post Link to post Share on other sites
steve roberts 9,242 Posted May 4, 2022 5 hours ago, OveFundinFan said: Some riders used an engine cover on the right side of the engine to protect the left leg from engine heat burns. Is that what you referring to.? For grass tracking I used motox leather trousers and they had a burn mark just abut the inside knee area. When my brother attended an Olle Nygren Training School at King's Lynn he always referred to a bolt that used to get red hot and cause discomfort on the inside leg! 1 Share this post Link to post Share on other sites
rusky 113 Posted May 4, 2022 Not one of my best photo's but I'm sure you get the ghist... anybody else remember the Erich Baier Red Rockets of the late 80's, early 90's ? Share this post Link to post Share on other sites
jenga 2,998 Posted May 4, 2022 (edited) i was told that painting engine parts black was something to do with the drag factor while going down the non bendy bits of the track , plus te shale did not stick to it as much as the stock ally . ones that were any other colour were not as quick ast he black ones . i think ! thats why Honda mx bikes were the quickest around . hence the name black rockets . LOL Edited May 4, 2022 by jenga 1 Share this post Link to post Share on other sites
topaz325 1,853 Posted May 4, 2022 Minimum engine weight 77.0 Kgs. Share this post Link to post Share on other sites
MARK246 243 Posted May 4, 2022 57 minutes ago, topaz325 said: Minimum engine weight 77.0 Kgs. Minimum 77 kgs is for the whole bike Share this post Link to post Share on other sites
