Paul's Karts Head

Trivia: If you've ever wondered what that stands for, it's "Fischer Aktiengesellschaft." It is a bearing company founded by Friedrich Fischer in the middle 1800s which of course predates the modern meaning if pronounced as an acronym. The brand is now owned by INA. They're good bearings IMO.
This comment sent me into a world of reading about that company. Quite interesting.

Turns out that the Fag factory was right down the road from where the Army had me stationed. schweinfurt-company-headquarters-of-the-bearing-manufacturer-schaeffler-HJ4TCE.jpg


I'm running one of Paul's heads on my drag project. I only recently got the engine going and am probably going to be swapping carbs and putting in a billet cam due to running the 60lb springs (was talking to my friend about that few days ago as he's doing a destroked 212 in a Bonneville bike). From the very little I've ridden the bike it feels like it's making some good power so far. It sounds great and is ridiculously loud.

I went with one of his heads with all the bells and whistles. He even did some shit for free due to his welder crapping out making me wait an extra week and a half. I'm running all the billet parts (rod, flywheel, side cover), a .308 cam, Black Venom 1.3 rockers, billet lifters, CM push rods and a 28mm flat slide carb. The carb is a knock off and the one spot I cheaped out. I want to get a real Mikuni for it as I'm not a fan of these Maikuni carbs after running one on another bike. My problem now is that the bike is so fucking loud I can't really mess with it at my house.

I don't have any experience with other modded heads. My friend (the one building the Bonneville bike) did do some porting on the head I have on my CT200U. It was mild though so I wouldn't put it in the same category as built heads.

I will say that Paul has great communication. He answered all my questions and kept me updated through the whole process. I've bugged him via text about some other stuff and he was always fast to reply.
I ordered the non Hemi 212 head with the big valves and the cam. Will have everything except I cheaped out on the carb too. I will Admit too that Paul visited with me for about 30 minutes before I purchased it. He also helped me out with some of the technical stuff too! I’ll let you know how the build turns out. Got about two weeks until it arrives.
Before going into any build, determine what it'll be used for, i.e. drag racing, short course, street bombing, etc. Then check availability of parts needed and what's going to need done to make them work, i.e. tires, brakes, wheels, shocks?, welding, etc. Having the wrong tires on a drag bike or not being able to stop within a reasonable distance because you couldn't weld on the right caliper bracket defeats the purpose. Building a drag racing engine and using it on a MX course, again, defeats the purpose.

There is a science to engine building but trial and error and implementing your own ideas can often make the difference. All these guys seem to use big terms and the one who uses more of them sells more parts. A lot of the 50 point list he talks about in his video are just things that need to (or should be) done when building a head anyway.

I noticed in his video he talks a lot about "Flow" and how his heads flow better. Well that's all fine and dandy but if your intake manifold doesn't match the intake port on your head, it becomes a bottleneck. I have one of those 24/28mm flat slide intakes and I noticed it tapers to the stock port size, If left alone, it will restrict airflow and defeat everything that went into the head.

What I do is, determine what I want to build it for, choose a cam that is suitable for what my intended use is, figure my target RPM range, compression ratio, valve size and spring pressure and go from there. Bigger isn't always better, matching the right components will outperform the bigger is better mentality. Take polishing ports for instance, one would think that the smoother the better/faster the air flows thus making more power. I've seen stepped ports outperform polished ports of the same size on race car engines, due to the design the turbulence actually mixed the fuel/air better going into the combustion chamber.

The one thing I noticed on all of the Pauls Karts heads is the pitting in the welded portion of the combustion camber. While it is hard to weld cast aluminum, those pits will cause carbon "Hot spots" and can cause pre-ignition which can cause catastrophic failure. Also take into consideration that race engines are rebuilt/replaced on a regular basis and they aren't intended to be built for reliability. 60lb. spring pressure may work on an engine that's going to be torn down after every fifth race but don't expect it to run down to the corner store every day for a month without ruining your cam. Speaking of cams, invest in some cam break-in lube. Breaking in the cam properly is probably most important thing one can do to prevent premature lobe failure!.
what can I expect out of this thing?
To be pissed off unless you do the cam, intake, carb etc etc at the same time without drooling over the lift and picking the first one you see.
Theres no magic one part.
The head cam intake carb and exhaust all have to match up or one is wasting their time.
And then I didn't see thst you mentioned a new clutch?
Be ready to replace that the first day.