Hond hi-pro head or port & Polish?

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Soapbox kid

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I'm trying to get more power out my Predator 212 mods already made
Blueprinted Carb,airfilter,header pipe,mod-2cam,
mods to come 18lbs springs.flywheel &rod kit.
I came across the head P&P d.i. y. But don't wanna take that chance & a shop would be has much as the head with a hit or miss setup. What should i do?? I may buy a old head & try it but what tools are needed & what can I use has a reference?? Thanks for the help.
 
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Soapbox kid said:
I'm trying to get more power out my Predator 212 mods already made
Blueprinted Carb,airfilter,header pipe,mod-2cam,
mods to come 18lbs springs.flywheel &rod kit.
I came across the head P&P d.i. y. But don't wanna take that chance & a shop would be has much as the head with a hit or miss setup. What should i do?? I may buy a old head & try it but what tools are needed & what can I use has a reference?? Thanks for the help.
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Have you replaced the internals with billet parts. If you haven't, I wouldn't put those valve springs in yet.
 
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smgs92

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once you put that flywheel and valve springs its a world of difference I just regeared my mini bike with the same engine and it hit 50mph easy with room to go.
 
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Ok no springs until I get flywheel & rod.Has for my gearing I've played with them &according to My local law I'm pretty fast...But I want more I want to have the fastest Clone in my town.So will the 18cc be better or just get one made.I've been in contact with Tim of Smallengincam.com & he has a setup he said will be all I need for a very nice price.But that's not really learning that's just buying & installing a part.
 
jamyers

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landuse said:
Have you replaced the internals with billet parts. If you haven't, I wouldn't put those valve springs in yet.
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Soapbox kid said:
...flywheel &rod kit....
Click to expand...

Yup, looks like he has/will. I missed the rod part at first glance too.

Soapbox, I've ported several heads + intake and exhaust manifolds for both cars (Buick 455 and Ford 200) and my kart (Briggs 8hp flatty). My experience and reading is that unless you're truly going for that last 1-2% (where you're going to add material and reshape the ports), you can do it yourself and save the $, plus gain a skill. It's not that hard, all you're trying to do is make a smooth passageway for the gasses to flow.

Check out:

http://www.pirate4x4.com/tech/billavista/PDFs/Head Porting DIY by Standard Abrasives.pdf

http://www.popularhotrodding.com/en...re/0412em_porting_cylinder_heads/viewall.html, and

Do some reading, then practice on some scrap aluminum to get the feel, then go slowly. Your finger is your best reference!
 
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Jamyers thanks for the link I now know what I have to do.Buy one & work on my old one in my time. I hate down time so doing it myself & fouling it up.Will have me side lined I get another one & work on the old one I can R&D my own work & still ride..What tools are needed I've heard people used a drimal to do it.
 
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smgs92 said:
http://www.arcracing.com/servlet/the-815/BSP-Clone-Stock-cylinder/Detail
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Hey, thanks for the pointer - I didn't realize a high-comp head was so cheap!

Although if you look at the bowl areas around the valve guides, those aren't ported - and looks like they'd gain a LOT from diy porting; taking those ledges and sharp edges out will only help.
Soapbox kid said:
Jamyers thanks for the link I now know what I have to do.Buy one & work on my old one in my time. I hate down time so doing it myself & fouling it up.Will have me side lined I get another one & work on the old one I can R&D my own work & still ride..What tools are needed I've heard people used a drimal to do it.
Click to expand...
I'd be real tempted to get that $45 head, clean up its ports and bowl areas, then swap it on.

Some folks use a Dremel, but it'll take awhile - metal cutting with them is really above their capability, but if you've got one and take the time it'll work. I use an air-powered die grinder at 40-60 psi with a round-nose carbide bit for the rough cutting, then switch to sandpaper rolls for the finishing.

It'll pay to practice on something, at the very least practice by taking off the casting flash or some unused part of the outside of the head (maybe an unused bolt boss?). The speed of the cutting tool is very important, best to start slow and work up to a speed where you can cut and control the best.

Here's my take on porting, from a previous post over at fordsix.com:
jamyers said:
The consensus among Buick engine builders/testers is that for anything short of a full-race drag engine, basic porting is good, polishing is bad.
Porting meaning basic stuff - cleaning up casting lines, the bowl area, reducing the enormous valve guide boss, making sure the port floor makes a nice smooth curving transition, and blending the valve cuts. Leave the intake walls rough and the exhaust reasonably smooth (100-120 grit).

Polishing anything but the exhaust side is seen as a waste of time/money, unless you're building a 7000-rpm screamer. Then you go nuts reshaping and polishing while your wallet gets significantly lighter.

In my limited street-engine-only experience, there's a really steep return-on-investment curve...basic port and bowl cleanup will make a real difference, but beyond that the gains go down pretty fast while the cost goes up as fast or faster.
Key areas to look at:
#1 is where the intake floor transitions down to the valve, it needs to be a nice smooth curve without bumps or lips to spoil flow. Most times you can lay this short side back and it'll help (but be careful you don't hit water)
#2 is the valve guide boss, most of these are enormous, and right in the middle of the way (especially on the exhaust side).
#3 is the bowl area where the valve seat cuts are. Make sure there's a smooth transition.
#4 Make sure the entrance to the intake ports aren't bigger than the intake manifold exits (not a problem on Ford integrated-manifold heads), and make sure that the exhaust manifold/heater passages aren't smaller than the heads exhaust passages. From carb to tailpipe everything can get bigger or stay equal, but not smaller.
Click to expand...

Here's a couple more links, just for fun:

A Thread detailing a Gasket-Matching project I did.

Pic of my finished Buick 455 heads, note the bowl areas and compare the valve guides to the ones on the $45 head above.
 
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