Modifying heads.........

[Guest]

I,VE got a 1980 gs1000E ,,, i rebuilt the top end.... with 1/2mil over pistons..... etc.... on the head ,,, i opened up the EXHAUST ports slightly to match my header size....and then I polished to a mirror finish the head of each valve .... and angled out the chambers slightly using a head gasget to help me... then ,,,i polished each chamber to a mirror finish ,,,finally I used bearing blue,,, which you can buy from any engineering supplies,, its fairly cheap and will last you a life time... ..and hand lapped each valve in ,,and also checked with bearing blue each valve ........I did not touch the inlet ports at all.... a day later I had a nice head that performs well ... and made a difference .. along with that I rejetted my cv carbs 1 size up on main and pilot and lifted the needle 1 spot up .... .... autosol also does a great job polishing alum....... if you have a bunnings store nearby or something similar.. they sell a small 48 piece demtrell kit for under 20bucks..... with grinding stones /polishing pads carbide bits etc .... and its rechargeable ... it will recharge while you have a coffee..........hope this will help somebody .... regards david from kaniva australia

[feelergaugephil]

Nice job, I too use Solvol Autosol on all my aluminium.
I also polished up my inlet/exhausts valves to mirror finish including the inner chambers. Time consuming, but isn't it all the fun!

[trippivot]

porting the exhaust only will ruin your low end torque and make a engine that is prone to off idle stuttering and de-cel popping and backfiring.

the proper ratio is 60% of exhaust to intake. and stock the exhaust flows over %75 of the intake already. (no need to open exhaust side)

I like a mirror finish on the hemi bowl and the exhaust side ports

intake side is where you clean up the casting flaws with no finer than 180 grit surface finish.

that is good info if you need to tweak out on your head

[doctorgonzo]

I used a dremel on the intake side to get out the casting lines, but left it rough, and only cleaned up on the exhaust side as I had been told you didn't want to open it up any as it would slow the flow of gases.