Rocksolid's billet head review.

adrian101

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Apr 10, 2011
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Well recently i purchased the "Billet Aluminium 70cc Performance Head" from rocksolid engines and thought i should do a review on here to tell you guy's about the pro's and cons of the head.

What I've notice so far with the billet head is the difference in compression. With the stock standard head the PSI was (115), now my engine has PSI (122). The billet head has given my engine a more beefer sound and has increased throttle response by around 30%.

With the standard head i was having trouble with my engine bogging down due to the gear ratio as i am 110kg's and i have a 36t sprocket on the bike. basically my engine had NO B#LLS to move me lol now with the billet head it doesn't have a problem moving my fat a#s :) I can't believe that a change of the head could increase the performance so much. Speed gain is an extra 5km/h which makes my top speed now 61km/h (i know people on here have better speeds but still, its an increase for me).

The only cons is the increased heat of the engine. as there are less air fins then the standard head it heats up more. I fixed the problem by using a richer mix and changing the needle settings to rich. I Have also had 3 blown exhaust manifolds. I don't know if it is caused by the billet head or not. I'm guessing it is due to compression but i don't know. I now have a copper Exhaust manifold Mwahahaha :giggle:. one other problem was piston slap (when spark plug hits piston) which was fixed with a slightly bigger head gasket.

I paid $109 which includes postage for the billet head. Do i believe it was worth it? Honestly yes. Apart from the cons which where easy fixes i have seen a big increase in performance.

I 100% approve this product and think whoever made it is a genius lol I thank him!
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putting a thicker head gasket on will decreas the compression.
"piston slap" is not the plug hitting the piston. "piston slap" is a side to side movement of the piston as it goes up & down in the cylinder, due to worn out rings or a worn cylinder.
if the plug is hitting the piston, the solution is a shorter reach plug.
Are you sure that you didn't just lose all of that compression that the head is giving you by adding a thicker head gasket?
 
Are you sure that you didn't just lose all of that compression that the head is giving you by adding a thicker head gasket?

I placed the thicker head gasket on after i tested the compression. As of now i haven't tested the psi. I'm guessing it would be lower but i will test it later on today :)

sorry about the wrong wording on "piston slap", i only used that word as that is what the guy who sold me the new spark plugs told me that was the correct term for what was happening.
 
yes the bigger gasket will decrease compression. you just need a shorter reach plug. also are you sure the piston is hitting the plug? did it close the gap? or did you just hear a sound and thought that was what was happening? because with the higher compression head, you may get some piging if you dont use a higher octane gasoline. im not sure but you maybe want to go with something like 89 or 91. im not sure what you have in your part of the world... but it wouldnt hurt to try. because you might even get more power too.
 
yes the bigger gasket will decrease compression. you just need a shorter reach plug. also are you sure the piston is hitting the plug? did it close the gap? or did you just hear a sound and thought that was what was happening? because with the higher compression head, you may get some piging if you dont use a higher octane gasoline. im not sure but you maybe want to go with something like 89 or 91. im not sure what you have in your part of the world... but it wouldnt hurt to try. because you might even get more power too.

Yeah it slammed the gap closed. I was like "that didn't sound good" when i took the plug out the gap was full closed :cry:. The engine started, then i heard a really loud "tin tin tin" then the engine died lol.

The spark plug i have now works fine and doesn't hit due to the gasket. Also the PSI compression of my engine is still (122) so i haven't lost any from placing a thicker gasket :D
 
I have a RockSolid Billet Head on my 66cc Grubee engine. Works great :) Never had a problem with the sparkplug. I asked the guys at RockSolid what sparkplug they use, and installed one with the head. Also, ordered their head gasket.
Yes, it's a little pricey... I'm just waiting for my Grubee to die, then I will buy his 66cc engine. Nicely built :)
With just this mod, and a Dellorto SHA 15.15 carb, it made a HUGH difference in power.
It turned that little rice burner into a little power house. I live in a hilly area, and wanted to add power to climb. I used to have to 'help' peddel up steep hills, but no more. Now the engine climbs like a champ. 'O' did I mention I weigh 220 lbs! :)
 
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