What needs to be done to heads to increase valve size?

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Sep 19, 2002 | 07:31 AM

Reckless

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From: Canton, GA

What needs to be done to heads to increase valve size?

Have access to some larger valves. Mine are stock sized Manleys right now. What will need to be done to the heads to insert the larger valves (2.05/1.60)?

Is it just recutting the seats and unshrouding? Or do the guides need to be moved? Any input appreciated! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Sep 19, 2002 | 08:36 AM

Nine Ball

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Re: What needs to be done to heads to increase valve size?

2.05/1.60 valves will require the stock valve seats be machined out and replaced with larger diameter ones. Its labor intensive. If the stem is a different diameter from stock, then the guides will need to be replaced as well.

Tony

Sep 19, 2002 | 08:55 AM

Reckless

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Re: What needs to be done to heads to increase valve size?

Tony...these are actually valves that were in an MTI head, so I'm sure you can elaborate on the valve type and sizing.

I believe they are 2.055 and 1.60, but haven't measured them yet.

So I'm looking at new guides, reseating, and valve job?

I plan on tweaking the ports anyway, so replacing the guides isn't a big deal.

Todd

Sep 19, 2002 | 09:35 AM

Nine Ball

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Re: What needs to be done to heads to increase valve size?

Yes, MTI uses the 2.055/1.60 combo on their Stage 2 heads. The older heads used off-the-shelf stem sizes, and required different guides. A little over a year ago MTI started using custom valves manufactured to their specs with stock sized valve stems (metric).

-Tony

Sep 19, 2002 | 10:05 AM

Reckless

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Re: What needs to be done to heads to increase valve size?

Not sure which ones they are. Do you know the diameter of "stock" stems? I can measure the bigger ones to determine if I need new guides.

Todd

Sep 19, 2002 | 10:59 AM

Jason99T/A

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Re: What needs to be done to heads to increase valve size?

<blockquote>quote:<hr />Originally posted by Reckless:
Not sure which ones they are. Do you know the diameter of "stock" stems? I can measure the bigger ones to determine if I need new guides.

Todd<hr /></blockquote>Stock is 8mm. MTI used to use 11/32" valves.