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 Low Cost and Effective Head Work

Low Cost, Effective Headwork!

By Mike Kojima

My race in the inaugural MPTCC race ended with a bang in the practice before qualifying as my SR20VE decided not to cooperate in a big way.  Tearing down my engine afterward I found that one of the exhaust valves had lost its head.  Fortunately the valve head did not bounce around in the combustion chamber and cause more damage, probably because I had shut the engine off and pushed in the clutch the second I felt the power fall off.

Low Cost and Effective Head Work

 The normally bulletproof Dog II ran strongly all day at the inaugural MPTCC race until it suddenly lost an exhaust valve with no warning at all.  This was a bummer because it was one of the fastest TU class cars.

I took the head over to my old friend Tom Fujita of Portflow Design to see if he could fix it.  The severed valve head had messed up the valve seat but the rest of the head looked to be ok.  Since the SR20VE is a JDM engine that does not have a lot of spare parts avalibe in the USA  I was hoping that Tom could get it back together.

Low Cost and Effective Head Work
We were having fun with Dai Yoshihara and Joon Maeng, half a lap later Joon was on fire and we had a dead engine.  Real bummer.

Tom suggested while the head was apart that I let him clean up the ports a little and to do a good radius valve job.  Although I didn't need to make any more power for the MPTCC TU class, I thought that cleaning up the head would make a nice tech article.

Low Cost and Effective Head Work
Ugh.

 

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Comments

jamal
# jamal
Monday, April 11, 2011 10:25 PM
Tom at Portflow is THE MAN!
JDMized
# JDMized
Tuesday, April 12, 2011 12:40 AM
Tom Fujita might be the man down in SoCal, but when I called Port Flow several months ago asking if they could massage my 2RZ Toyota head, the guy that I talked to seemed to be a big pot-head. (I doubt I was talking to Tom).
Anyway, when I told him that my head is from a 2004 Tacoma, the guy kept telling me that the only Toyota head they work on is the 1-2JZ.
Like I said, Tom Fujita might be a great guy and knows his stuff, but his staff was incompetent to say the least.
Asides, I hardly doubt Port Flow only works on the 1-2JZ for the Toyota, but that's not the point.
Fly'n_Z
# Fly'n_Z
Tuesday, April 12, 2011 6:30 AM
Looks good Mike! Even if you do have to restrict things somewhat on the tope end to meet the power to weight requirements the improvements throughout the rev range should make it worthwhile.
jeffball610
# jeffball610
Tuesday, April 12, 2011 7:54 AM
WOW! Look at the intake gains at the low lift area. Impressive. Are there any other small tricks to get a little more flow? A lot of people talk about gasket matching the ports, but I would think that might hurt flow and might cost a little extra at a professional shop. What can the average guy do to help some head flow without doing damage?
Mike Kojima
# Mike Kojima
Tuesday, April 12, 2011 8:16 AM
Portflow turns work around fast. Every other head porter takes months or even years and always has some weird excuse why your head isn't done. My last head took 18 months from a reputable head porter.

My prior two heads are at two famous shops in our area. one for 5 years the other for 8 years I will never get them back even though they are partially paid for. Flakey, lagger head porters the main reason why I gave up on the SR20 and now mostly only do engines that Cosworth has CNC heads on the shelf for.

Portflow only used to do Honda heads but now they do all heads. So now I use them and will probably start doing engines again!

Tom talks gruffly and slowly and might sound like a pothead but he knows his stuff. He is always busy and at work so he is not always too patient, but he has to be, he is actualy working and getting your stuff DONE. Their service is refreshingly fast.
Chris
# Chris "Shaggy" Allen
Tuesday, April 12, 2011 10:47 AM
IMO I think .040 is fine on N1 cams.. My thought is that and this is speculation as I have not checked yet but.. The N1 cams though have more lift the duration is greater as well and by this the valve opens and closes at a slower rate due to duration and because of that IMO there is less chance of contact ... I have been running my VVL at .040 without problem as of now. Granted I have not had it at the track for a bit and probably doesn't see the track time yours does. This is my opinion. Also I have my VVL set to shut off above 8200RPM so if it does over rev it drops to the small lobe. Just hope it does it in time to avoid contact..
narcotix
# narcotix
Tuesday, April 12, 2011 11:35 AM
I just brought a pair of Ford heads down to Tom's Sensei...Uncle Rick! Those guys combined have more head porting knowledge than most states....
bill@dentsport
# bill@dentsport
Tuesday, April 12, 2011 12:06 PM
Great article Mike. I need to switch to a VE next winter.
Der Bruce
# Der Bruce
Tuesday, April 12, 2011 4:36 PM
If I'm reading your intake flow correctly, it looks like you could actually make a little power in the lower rpm range while possibly improving throttle response? Looks like the TU class is gonna be tight this year!
Mike Kojima
# Mike Kojima
Tuesday, April 12, 2011 4:57 PM
I think 0.040 is ok for street but not for racing where you are always at high rpm and sometimes mess up.
Mrad
# Mrad
Wednesday, April 13, 2011 4:09 AM
I always liked how the old "how to keep your vw alive for idiiots" back section had a instruction on cc' ing the heads. Not sure how much of a diffrence that was going to make on a 36hp engine
mxpop
# mxpop
Monday, April 18, 2011 3:43 PM
I heart Tom!

He helped us make 750whp on our championship winning Subie :-)

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