Larger head valve?

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2009: Larger head valve?
Top of pagePrevious messageNext messageBottom of page Link to this message  By tyrone thomas on Wednesday, December 23, 2009 - 11:40 am:

Is there a valve with a larger head that can be run in the T engine?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Wednesday, December 23, 2009 - 11:49 am:

Stock valves have 1.470" heads. Chevrolet small-block V-8 exhaust valves measure 1.500" and the stems are 1/32" larger at 11/32".

As close as the head is to more than 180 degrees of the valve head's circumference, big valves are not the answer to more power since the valve is so shrouded by the head.

More lift and duration are the answer if power is what you want, just remember that low speed power will be reduced.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chuck Hoffman on Wednesday, December 23, 2009 - 12:10 pm:

You can also get a 1.6" Chevy valve but you will need to do some relieving in the combustion chamber. A 1.5" just barely clears the head.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jeff Humble on Wednesday, December 23, 2009 - 12:15 pm:

Tyrone,
I like the modern Chevy valves, they are inexpensive and available at all auto parts stores. The modern keepers are way better than the pin and washer Ford used and many repro pins are too soft and break.


Top of pagePrevious messageNext messageBottom of page Link to this message  By tyrone thomas on Wednesday, December 23, 2009 - 12:43 pm:

Yes mr. Seth that is what I had in mind. An extra helping of power.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Wednesday, December 23, 2009 - 12:49 pm:

Get yourself a Stipe 280 or other high-lift cam then. But get a high-compression head first.


Top of pagePrevious messageNext messageBottom of page Link to this message  By tyrone thomas on Wednesday, December 23, 2009 - 12:54 pm:

The high comp will happen. Now lets talk cam. The 280 is more a race cam? Im sure not so ratical but will increase mid range power and pick up but with a smooth idle?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Wednesday, December 23, 2009 - 01:02 pm:

It opens the valves 0.030" further and probably has some more duration. You'll lose some low-speed power but it's hardly what anyone would call a racing cam.

Since there's some loss of low-speed power, probably works best with an auxiliary transmission or Ruckstell which gives you an intermediate ratio between low and direct.

The above is true of a stock Ford cam also - can't have too many gear ratios to choose from.


Top of pagePrevious messageNext messageBottom of page Link to this message  By GLEN CHAFFIN on Wednesday, December 23, 2009 - 01:37 pm:

We sell the Ford 351 Windsor exhaust valve which has a 1.542 in head and the correct length for the Model T. If you use any bigger head valve you will have to modify the head gasket and relieve the head. Our 280 lift cam is designed to have the same low end torque and horsepower as the Ford stock cam while providind superior high end performance.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Robison-Montana 500 President on Wednesday, December 23, 2009 - 01:46 pm:

Stock valve head size is 1.460"


Top of pagePrevious messageNext messageBottom of page Link to this message  By Keith Townsend, Gresham, Orygun on Wednesday, December 23, 2009 - 02:44 pm:

Glen-
I have a Z head on my '19, a Reader head on my '15 and run your "touring grind" cam in both. I have Ruckstells with 3:1 gears in both also and I am happy with the results I have.

How is your 280 lift cam different from your Touring grind? What does "280" signify?

-Keith


Top of pagePrevious messageNext messageBottom of page Link to this message  By Noel Keefer on Wednesday, December 23, 2009 - 03:19 pm:

All,

The Chev valve head diameter can be cut to 1.5" very easily to fit the T. The valves are very machinable. Lots easier than reworking the block, gasket or head, unless you want to.
I got some IROC valves but IIRC the valves were more restrictive due to the beefed up tulip material below the valve head.

Regards, Noel


Top of pagePrevious messageNext messageBottom of page Link to this message  By GLEN CHAFFIN on Wednesday, December 23, 2009 - 04:15 pm:

The 1.542 valve head fits very nicely with no modifications to gasket or head. It's about as big as you can use without modifications. We have a Driver II Reground cam. It has 0.270 lift and stock 115.5 Deg lobe separation. Performance is about equal to the new Stipe cam. The 0.280 lift new cam has 109 degrees lobe separation and has better low and high end torque and horsepower than the Driver. Both of these cams as well as the Stipe are very good cams.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John H on Wednesday, December 23, 2009 - 06:15 pm:

The repro valve retaining pins are still too soft last time I ordered a set which was about 6 months ago. I've changed over to ground off 7/64" drill bit shanks - problem fixed.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Andrew Gordon Wells on Wednesday, December 23, 2009 - 09:46 pm:

I have had a repo valve pin shear off. Lucky I was only 4 mile from home and made it ok on 3 pots. I now use 3 mm needle roller bearings as used in gearboxes. They are a neat fit and are about the same price as the repo pins.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Thursday, December 24, 2009 - 11:43 am:

Interesting to find out that 305CID IROC-Z exhaust valves are different than other SBC 1.5" exhaust valves. I guess there's lots to learn most every day on this forum.

Had I known that they were more restrictive and therefore undesirable for a T, I guess I'd never wasted my time shipping them to Noel.

I guess I now know why he never thanked me for them. :-)


Add a Message


This is a private posting area. Only registered users and moderators may post messages here.
Username:  
Password:

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration