What's to be gained with port and polishing the heads? Is there enough gain to warrant the cost? I was told today buy someone who has been around the MM world a long time that he doesn't think it's worth the extra cost. Opinions...

...are like assholes...

What are the goals for you rig..

Good valvework and decking go a long way. Will you be mad when your buddy slowly pulls by you 1 mph faster and you think shit, I should have ported them. if the answer is no then don't sweat it

Castleman?

You get your most gains off decking or rods/pistons. More compression. Port/polish is one of those things that might add 1-2% more power but every little bit helps.

the man who gets paid to port/polish probly sees the most gains from doing a lawn mower engine. lol

These are Kawasaki heads on my shit, what do you think the air flow is doing. Oh and BTW, the air flow effects power, speed, load , and all the basic functions of the engine.

Stock
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Cleaned up
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Notice all the sharp edges are removed to allow a better transition and flow throughout the head.

But then again, that's my opinion.

When done correctly it will compliment better airflow in and out of the engine. If you look at a raw casting there are flaw all over the place. Just cleaning them up will help, reshaping the port is more complex, but when done to match a specific build to match camshaft and target RPM you can really make some improvements.

Will C made good points about valve work. It is probably one of the MOST important things about head work. I don't care how "pretty" your port work is; if your valves are not properly sized to the seat and seal to the seat, you have one pretty piece of shit.

Opinions are like assholes and I have my own method of what I think works the best in everyday work horse engines. This appeals to most guys using their rig for multi purposes. IMHO if you want to go fast all the time get an outboard. I'm about making useable torque in a given range to make the engine work and be pretty darn reliable.

so I'm not trying to be that guy who is racing everyone...I don't fish my boat much but I do take the fam out they love to ride where my big boat can't go...I want the better performance gained by the headwork, carb, exhaust. A cam will come later...my boat is smaller but carries a load decently now with the 3 blade but haven't tried with the BB I just put on but I expect it to be better.

And as far as the outboard statement you know good and well why we don't have outboards they won't go where we need them to go and we would like to have a "faster" motor than stock. If not you would just replace the weak links with good stuff and roll out. Especially with all those pages I read through last night about the reliability of the kawi's why would you build it and have speed videos posted in the thread? Good read by the way. Thinkin out the box is what made America what It WAS to begin with.

I didn't realize you had a Pd. If it's not a newer wet gasket engine you will likely have case leaking problems

I wasnt asking a question it was a statement about what I want out of my build in a way. I don't have a PD I have a GTR but I'm not one of those "GTR" owners

10 4

On the other hand you did just spend a lot of money on a carb and exhaust setup. Why not complete the package

Yeah I'm gonna. I got a guy here gonna port and polish for $200 he does great work. Have the heads shaved and valve job done at the hot rod machine shop local. I spent the majority of 3rd shift last night reading through thread after thread trying to figure out all that needed to be done.

Good call. You will sleep better

I work 3rd shift we never sleep lol

South Carolina

It does help!My engine was turning 6400 RPMs and I ported and polish the intake and throat on carb and now it turns 7250 rpms

You got a rotary motor

Summm bitch!

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