you can probably grab one from the jy for pretty cheap, especially if you take your blown one back as a core.Originally Posted by MessyHonda
you can probably grab one from the jy for pretty cheap, especially if you take your blown one back as a core.
As Rich will probably tell you, most of the improvement in headwork is around the valves. One thing I discovered is that you need to tell the shop you want a "performance" valve grind. In my case they just touched up the seats and basically restored them to factory specs. This is good for long term reliability but much more restrictive for flow, so I took it back and had them do a performance grind. The performance grind has much narrower seats and the cuts above and below the seat are deeper.
Some pictures:
This was the first pass. Look at how wide the intake seats are.
This was the second pass. Much narrower seats and you can actually see the lower cut now.
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how much did that run u
Total for the head was $300. That included before and after washes, remachining the surface, cutting the valve seats, and regrinding the valves. They didn't charge me for the regrind on the seats which was cool since I didn't tell them to do a performance grind the first time (oops). If you're interested you can check out the whole rebuild here:
http://www.preludepower.com/forums/s...d.php?t=238337
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hmmm thats not bad so priity much u gave them a complete head had all the work done then it came bacl complete
Not quite. I gave them just the head casting and the valves. I did all the disassembly/reassembly. It's pretty easy if you have a valve spring compressor.
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it's also nice to have a friend help you take out the springs, casue some of them are pretty subborn
are you going to use the a18a double springs?
Also the machine shop he used were very professional the chamber wall would be razor shape after the head had been skimmed but the machinist took the time and trouble to bevel edge the whole chamber circumference on each one. If this was not done apart from slicing fingures open if touched would also cause pre ignition and detonation problems as the sharp edge would get red hot from firing and would cause the incoming fuel mixture to ignite before it was supposed to. Also they did the seats to a pretty descent spec for a normal machine shop, you can still have a lot of improvements to those seats but would cost more money as machinary needed would be very expensive and the seats would need to be hand finished too which would ramp up costs, but as a cheap performance upgrade he did well to get what he got for the money. The rest of the head he did himself with a bit of advice from myself, be nice to see a pair of DCOE's on there instead of a 38/38 but i suppose you have to start somewhere!! About time you started getting it tuned properly and down the rolling road for some finer tweeking especially when you get your cam pulley!!
Hey Rich! You think I've been slacking off all this time eh? Not so. Well, mostly not so. Heh! I haven't updated my thread over on PP for awhile I guess. I'll get on that.
The 'lude has been running for awhile now and I have been getting some miles in now that the weather is getting better. The leaks are all fixed now. Most were simple things that I just overlooked. I've done a fair bit of tuning on the Weber and have even kept a record in the sticky Weber thread in the carbs section here. It's running pretty good now except that I've recently discovered a major flaw in the 38/38. Because of the way it's oriented, combined with the shape of the fuel bowl, the fuel sloshes to one side or the other during hard cornering. This creates either more or less pressure in the main circuit and causes the mixture to go rich or lean depending on which way you are turning. Right hand turns are bad enough that sometimes the engine will even stall out from being too rich. I asked a local Weber guru about this and he said there was pretty much nothing to be done as it's a result of the basic design of the carb. This is really disappointing because it's such a fun carb to play with, and the throttle response is amazing. So anyway that's why I've been thinking about a FI conversion.
Anyway this is getting off topic for here. I did want to mention though that I actually did the bevel on the chamber edges, not the shop. It's kind of a pet peeve of mine to have machined edges that haven't been smoothed over. I also did more work on the head after that picture, mostly to the chambers and around the valve seats. I thought I had some later pictures than that but I can't seem to find them now. Oh well. I did ask the shop one time if they could do 5-angle seats, and they said certainly, but the cost would be higher.
The cam gear will be interesting to play with when it comes in too. As well as the S&S header, whenever I finally get it back. The coating guy is slower than molasses in January. Hopefully in the next couple weeks.
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Not sure who you're asking but I used A18 exhaust (double) springs for the exhausts and A18 intake (single) springs for the intakes. The A18 intake springs are significantly larger than A20 intake springs.
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were can u get them and are they price and hard to install
I used the springs from the original A18 head that was on the engine (an A18 of course). You can get them from a junkyard or from one of the various honda parts web sites. Easiest thing to do is probably to go yank a whole head from a junked Prelude (carburetted, 83-87). That way you have all the platforms and retainers and stuff. You could buy all new parts but for springs it's not such a big deal. If you're getting a new cam though you should get new rockers.
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so u would say rockauto would have everything
oh and what would they be calle di tryed to look but found nothing
Last edited by ghettogeddy; 04-26-2007 at 07:32 PM.
Rockauto doesn't have everything and their prices aren't that good. Try here:
http://www.hondapartsdeals.com/
If you decide to get all new springs get the A18 ones. They cost the same and you won't ever have to worry about valve float. Honestly though I would just find a used head for the springs and such. It will be much cheaper and work just fine. Do get new rocker arms though (if you use a new cam).
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should the rocker arms be form a a20 or a18 or are there better lol
The rocker arms are all the same.
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ok cool ya i found the parts on the website u posted maybe if u have aim or if i send u the pic of the parts if u can tell me what all i will need i figure if im rebuilding i might as well go new u know
Now THAT is "kickin it old school"
That is the kind of motor I would like to have/see/run
Ghettogeddy are you going to bore over even if your block doenst really need it or not? You can save alot of money by not and still have a strong durable motor. A lot of these Honda motors dont need boring even after 200K and such.
well i figured boring is a good for performance right or am i wroung it should give me a tiny bit more power or shoudl i just spend the money on proformance pistons and and stay stock size with stock rods
Later tonight I can post a list of all the parts you need. I'm a master at navigating that website. I had LOTS of practice during my rebuild!
And I even printed out the diagrams and parts lists to make sure I didn't miss anything during assembly.
You will get very little extra power from over-boring. If you don't have to it's not worth the trouble. The shop will be able to tell you if it's needed or not.
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ok well then ill just get the regular piston size and go from there the ones im getting are about 60 are there any better performance wise pistons in the 150 range
agreed!
Ghettogeddy....
What are your goals for rebuilding? turbo, nitrous or just some na pep?
possible nitrous but more na build i was actually talking to a frind of mine and he said to have to tops of the pistons powder coated if im gona fun spray so thats another question ive never heard of anyone doing that is it legit
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