oversized valves

[stephensimmons]

Dose anyone know of a company that makes oversized valves for the a20a3 or what other honda engine valves would fit that are larger?

[guaynabo89]

not off the top of my head, but as long as the valve stem is the same length and the keeper groove is in the same spot the rest is easy. Well easy for a compitent cylinder head machinist.

all that needs to be done is the valve seats need to be opened up of course and valve guides can be replaced for ones with the matching valve stem diameter.

[A20A1]

Who did the larger valves... rjudgey, sean, openloop?

I think I remember 33mm intake / 37mm exhaust, the intake were modified exhaust valves.

[stephensimmons]

That size sounds bout rite i just didnt no where to get them after all my searching and thats probly why.

[guaynabo89]

ferrea couldn't help you?

[stephensimmons]

Ill give them a try

[cygnus x-1]

I've been investigating over-sized valves for many weeks now. There is NOTHING off the shelf from any of the major companies that will really work. Lots are close but none are quite right. Just yesterday I dropped off some specs at the local shop so they can order some custom from Ferrea. I don't have an exact price yet but I'll get one soon.

The intakes should be 32mm and the exhausts should be 37mm. You can maybe shoehorn in 33mm intakes but it really depends on how straight the seats are in the casting. I also added an extra 1mm to the tip to make up for what you would lose with a reground cam. I'll of course post pictures when I get the valves in.


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[Oldblueaccord]

That size sounds bout rite i just didnt no where to get them after all my searching and thats probly why.

Pics of Head development work


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[2drSE-i]

In for price on the custom valves

[guaynabo89]

back in d day (96-98 or so) it was really expensive. Not so much the valves, but the machining involved.

I also want to see how much they get quoted.

[cygnus x-1]

Well it seems that Ferrea wanted like $50 each so the shop guy decided to try SI instead. I don't have an exact price from SI yet but I'll report back when I do. There seems to be some confusion over the intake valve because of the extremely odd stem size (6.6mm). I think what I may end up doing for the intakes is to use 7mm stems and have the guides reamed out. The 7mm stems can be waisted down to 6mm to improve flow and will still be plenty strong.

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[guaynabo89]

yup

it was going to be alot of machining back in d day when I was researching it. I believe back then it was going to come out in an extra 800 or so.

I went with DPR to backcut and swirlpolish oem valves instead.

please post your results, but I'm pretty sure their pricing will be similar.

[cygnus x-1]

yup

it was going to be alot of machining back in d day when I was researching it. I believe back then it was going to come out in an extra 800 or so.

I went with DPR to backcut and swirlpolish oem valves instead.

please post your results, but I'm pretty sure their pricing will be similar.

I don't think it will be quite that much but we'll see. The valves themselves will probably be around $400 for the complete set of 12. Machine work I don't think will break $300 but I do plan to have this head milled to the extreme so I guess it could.

The valves are ordered though and should be in in a little over a week.


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[guaynabo89]

get er done.

lol


defknately take many pics when you do proxeed

[LX-incredible]

I don't think it will be quite that much but we'll see. The valves themselves will probably be around $400 for the complete set of 12. Machine work I don't think will break $300 but I do plan to have this head milled to the extreme so I guess it could.

The valves are ordered though and should be in in a little over a week.


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$700 for oversized valves? Let us know how they work out. I have a p&p head that's waiting for my decision on the valves.

[stephensimmons]

I've been investigating over-sized valves for many weeks now. There is NOTHING off the shelf from any of the major companies that will really work. Lots are close but none are quite right. Just yesterday I dropped off some specs at the local shop so they can order some custom from Ferrea. I don't have an exact price yet but I'll get one soon.

The intakes should be 32mm and the exhausts should be 37mm. You can maybe shoehorn in 33mm intakes but it really depends on how straight the seats are in the casting. I also added an extra 1mm to the tip to make up for what you would lose with a reground cam. I'll of course post pictures when I get the valves in.


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[cygnus x-1]

Your timing is impeccable. Just today I picked up the valves from the shop. I'll be putting pictures up of the valves (soon!) and the head work as it proceeds. I'll probably only post on Preludepower and just link it back here so I don't have to repeat every post. Stay tuned!


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[stephensimmons]

Your timing is impeccable. Just today I picked up the valves from the shop. I'll be putting pictures up of the valves (soon!) and the head work as it proceeds. I'll probably only post on Preludepower and just link it back here so I don't have to repeat every post. Stay tuned!


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[carotman]

That's cool!

[guaynabo89]

post up a side by side of the stock and aftermarket valves if you can.

[cygnus x-1]

Took me awhile because I'm so lazy. But here they are.

http://preludepower.com/forums/showthread.php?t=328825


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[Oldblueaccord]

hey great info!

Get that thing flow tested I'm interested to what our heads can make power wise.


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