Planet Minis

shmalphy · 01-15-2009, 05:49 AM

Has anyone ever tried porting their head for larger valves? What valves work? What are the specs to port it out? I live next to a technical high school with a machine shop that is going to help me

chasetheface123 · 01-15-2009, 05:54 AM

pm dood

firepower354 · 01-15-2009, 10:26 PM

Stock/Mod class? Otherwise, it's turd polishing at it's finest.

vetmxer · 01-16-2009, 05:03 AM

get an e22 head and the approriate piston. alot less work

dood · 01-16-2009, 09:35 AM

Unless you wanna spend alot of money and time, you are better off doing what VETMXER said.

The combustion chamber and ports are so small and while there is enough material to do things, It's not cost efficient to do it reguardless of if you have access to machines or not.

Paxracing · 01-16-2009, 10:03 AM

We are doing 4 now and will dyno next week. We also sell the over size valves with seat and yes we will have DOOD do some porting.

cyclerider57 · 01-16-2009, 01:27 PM

I've taken a stock crf50 head to 23mm intake and 19mm exhaust. I made ampco45 seats and titanium valves. To take it that far requires a great deal of work. Just to get the valves to clear you have to sink them in the head a lot. You then have to rework the combustion chamber including decking the head. A really experienced person will have hours alone just in the combustion chamber and valves not including porting. You can get +1mm intakes from fast50s and pax but anything bigger will require new seats to do it properly. Unless you are restricted to a stock head and want a big project, just get an aftermarket casting.

b-dub675 · 01-16-2009, 02:20 PM

maybe a stupid question but is it worth porting a stock 70 head???

firepower354 · 01-16-2009, 02:29 PM

Quote:

Originally Posted by b-dub675

maybe a stupid question but is it worth porting a stock 70 head???

Yes. About it being worth it. One of the better ways to go for an all-around 88-ish engine.

Kurlon · 01-16-2009, 03:12 PM

Quote:

Originally Posted by firepower354

Yes. About it being worth it. One of the better ways to go for an all-around 88-ish engine.

Hell, even 72cc motors respond, just don't go crazy...

firepower354 · 01-16-2009, 03:15 PM

Just did one for a buddy's daughter, with a 47mm Wiseco. Runs great. For an 11 year-old girl, or someone of similar mass

shmalphy · 01-17-2009, 04:34 PM

PAX, I PMed you and, I looked on your site. I can't find anything. Please respond.

NEWSCHOOL · 01-17-2009, 08:43 PM

how about an xr70 head on a 49cc high compression piston.

Paxracing · 01-17-2009, 08:45 PM

Quote:

Originally Posted by shmalphy

PAX, I PMed you and, I looked on your site. I can't find anything. Please respond.

I AM paxracing .,not paxracing tanya

cyclerider57 · 01-18-2009, 01:19 PM

Quote:

Originally Posted by NEWSCHOOL

how about an xr70 head on a 49cc high compression piston.

Easy Peasy Lemon Squeezy. Just deck the head a little to get a small enough diameter chamber.

01-15-2009, 05:49 AM	#1 (permalink)
shmalphy 2nd Gear Member Join Date: Dec 2008 Location: Billerica MA Posts: 591 My Mood:	porting/ oversized valves in stock head. Has anyone ever tried porting their head for larger valves? What valves work? What are the specs to port it out? I live next to a technical high school with a machine shop that is going to help me

01-15-2009, 05:54 AM	#2 (permalink)
chasetheface123 Chuck Norris for president! Join Date: Nov 2007 Location: Boyne City Michigan Posts: 4,817 My Mood:	Re: porting/ oversized valves in stock head. pm dood

01-15-2009, 10:26 PM	#3 (permalink)
firepower354 Advertiser Join Date: Oct 2006 Location: Flint MI Posts: 11,005 My Mood:	Re: porting/ oversized valves in stock head. Stock/Mod class? Otherwise, it's turd polishing at it's finest. __________________ If it has my name on it I did it;) FirepowerMinis.com Custom FPM parts and engines. Parts and service for all makes. Honda Trail Bikes parts and accessories. Pitster/Piranha/Thumpstar bikes, parts, engines and accessories.

01-16-2009, 05:03 AM	#4 (permalink)
vetmxer 2nd Gear Member Join Date: Feb 2006 Location: IOWA Posts: 764 My Mood:	Re: porting/ oversized valves in stock head. get an e22 head and the approriate piston. alot less work

01-16-2009, 09:35 AM	#5 (permalink)
dood 3rd Gear Member Join Date: Sep 2006 Location: Washington Posts: 3,055	Re: porting/ oversized valves in stock head. Unless you wanna spend alot of money and time, you are better off doing what VETMXER said. The combustion chamber and ports are so small and while there is enough material to do things, It's not cost efficient to do it reguardless of if you have access to machines or not.

01-16-2009, 10:03 AM	#6 (permalink)
Paxracing 3rd Gear Member Join Date: Mar 2004 Location: ca Posts: 5,518 My Mood:	Re: porting/ oversized valves in stock head. We are doing 4 now and will dyno next week. We also sell the over size valves with seat and yes we will have DOOD do some porting. Last edited by Paxracing; 01-16-2009 at 01:29 PM.

01-16-2009, 01:27 PM	#7 (permalink)
cyclerider57 Got Un-disappeared Join Date: Nov 2003 Location: Kansas Posts: 4,321 My Mood:	Re: porting/ oversized valves in stock head. I've taken a stock crf50 head to 23mm intake and 19mm exhaust. I made ampco45 seats and titanium valves. To take it that far requires a great deal of work. Just to get the valves to clear you have to sink them in the head a lot. You then have to rework the combustion chamber including decking the head. A really experienced person will have hours alone just in the combustion chamber and valves not including porting. You can get +1mm intakes from fast50s and pax but anything bigger will require new seats to do it properly. Unless you are restricted to a stock head and want a big project, just get an aftermarket casting. __________________ The wise understand by themselves; fools follow the reports of others. Goodness speaks in a whisper, evil shouts. -Tibetan Proverb

01-16-2009, 02:20 PM	#8 (permalink)
b-dub675 1st Gear Member Join Date: Aug 2008 Location: kalamazoo michigan Posts: 179	Re: porting/ oversized valves in stock head. maybe a stupid question but is it worth porting a stock 70 head???

01-16-2009, 03:15 PM	#11 (permalink)
firepower354 Advertiser Join Date: Oct 2006 Location: Flint MI Posts: 11,005 My Mood:	Re: porting/ oversized valves in stock head. Just did one for a buddy's daughter, with a 47mm Wiseco. Runs great. For an 11 year-old girl, or someone of similar mass __________________ If it has my name on it I did it;) FirepowerMinis.com Custom FPM parts and engines. Parts and service for all makes. Honda Trail Bikes parts and accessories. Pitster/Piranha/Thumpstar bikes, parts, engines and accessories.

01-17-2009, 04:34 PM	#12 (permalink)
shmalphy 2nd Gear Member Join Date: Dec 2008 Location: Billerica MA Posts: 591 My Mood:	Re: porting/ oversized valves in stock head. PAX, I PMed you and, I looked on your site. I can't find anything. Please respond.

01-17-2009, 08:43 PM	#13 (permalink)
NEWSCHOOL 1st Gear Member Join Date: Sep 2008 Location: CT / VT Posts: 123 My Mood:	Re: porting/ oversized valves in stock head. how about an xr70 head on a 49cc high compression piston.

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