Are oversized valves really needed?
 

Im rebuilding my 1930 Town Sedan motor and am adding a few upgrades such as high compression head, V8 clutch and weighted and balanced crankshaft. I know some install oversized valves and adjustable lifters but is this really necessary? Will I get more horsepower with this addition? What type of machining is involved to intall these bigger valves? Also, I hear others install a touring cam. Will a different cam make standard valves perform better or is it just used when intalling the oversized valves? Finally, are adjustable lifters recommended when using the oversized valves and touring cam or can they be used for the standard setup as well. It seems that valves will need to be reground some day but only after heavy mileage has been incured so why install adjustable lifters? My goal is to be able to drive the freeway at 55-60mph if needed on tours and I will be installing an overdrive in the future to accomplish this. Any ideas? Thanks.

Re: Are oversized valves really needed?
 

I'm kinda of the opinion of using a HC cylinder head, counter weighted fully balanced crank and assembly, somewhat lightened flywheel with V8 clutch and Bill Stipe camshaft. I would just as soon use the original non adjustable lifters.
But, that said, as long as the work is being performed, why not install over sized valves, open the ports for possible use of '32 manifolds and carburetor.

Re: Are oversized valves really needed?
 

A well rebuilt Model A Ford with overdrive will certainly go 55-60 MPH as configured originally. My car is stock with 3:77 rear and Brumfield 5.9 head and likes to go 55 but I usually don't go that fast unless I am in a hurry.

Re: Are oversized valves really needed?
 

Adjustable valve lifters or model B lifters that are longer than model A lifters will be required If you use a B cam or a cam with more lift. The reason is that original model A lifters will be too short unless you use modern valves. Bigger valves will help but will be shrouded on the manifold side and will probably need some relief work on the head that will in turn lower the compression.

Re: Are oversized valves really needed?
 

Are big valves necessary? No, but, every little thing you do to get more air through the engine will make more horsepower.
Adjustable lifters are a convenience, they won't add power. They are generally not used in racing engines because they are heavier.
The machining required to install big valves can vary depending on how much money you want to spend. More money, more air.
A performance cam usually goes along with other valve train mods.
In the end, it is the overall package that helps the most. Each item by itself does not add much.
All of the mods you are talking about have the added advantage of giving you better gas mileage also, as long as you don't drive with the gas pedal on the floor all the time.

Re: Are oversized valves really needed?
 

What do you really need?

A stock A from the factory will run 60 MPH all day long (or more).

Of course they were well balanced and machined properly.

Simply adding the HC head just takes advantage of modern fuels. Using a B type cam or better yet a new Stipe cam that is a modern science improvement over the B cam does wonders. BUT you must use the correct diameter lifter heads. Using the the wrong size might ruin the cam and throw off the valve timing. I suggest that you use what Stipe recommends if you go that route.

Counter balancing the crank is useless if they crank is not properly ground. A lot of cranks are not properly ground. So get it done by someone that will get all the center lines correct and put the correct radius fillet in the corners.

Larger valves are not really needed unless you plan on a monster motor. If your goal is running highway speeds and having fun then keep it simple. An overdrive is likely to be a waste of money unless you intend on driving zillions of miles on the highway.

Keep in mind if the bearing got 50,000 to 80,000 miles running 50+ MPH constantly when the A was new. That was without overdrive. So with our without counter weights that is what you should expect without an overdrive.

But as I always say, what could I know. I am only applying logic and how the cars were run in when they were new. Seems some think the car has changed a lot since it was just a used car.

Re: Are oversized valves really needed?
 

Hey Jim,
Very good inquiries ! And, it's very smart to start doing the research , as you are doing..now, before (mistakes) spending all the dollars required to achieve what you want.
Lots of good info given so far, and I recommend that you get Jim Brierley's recently published book , which addresses a few of your questions. Just enjoy the 'war stories' and save the 'nuggets' for your build. I think that he sandbagged and is holding out for the second/third edition ..which I will also buy:D. They (Pete/Jim and other fast boys) say...how fast you want to go depends on how much $ you have to spend:)

Re: Are oversized valves really needed?
 

It is my understanding that larger intake valves do make a difference; that it is not necessary to change the exhaust valve size.

My F150 has the 5.4 engine; the additional horsepower over the 5.0 was obtained by adding a additional intake valve to each cylinder.

Ron

Re: Are oversized valves really needed?
 

The adjustable lifters are almost mandatory unless you want to spend the day grinding and fitting, gauging valves inside a lifter chamber! Your call, adjusting with wrenches is much easier in my eyes.

Re: Are oversized valves really needed?
 

If all you want is touring, oversized valves are not needed. A mild cam, adjustable lifters, Snyder head are fine but you will not get the full benefit without a downdraft carb. As Pete says, its all a package. That's for the fun stuff.
I would recommend first getting a counter balanced crank, center main oil kit from Pirano's (its an easy installation) and a lightened flywheel. You won't feel much performance difference, but the engine will like those things. Try them first and see you want or need to build a hotter engine. They will give you a good foundation and the confidence to build about anything from there. Not much point in doing the performance stuff if the engine is not solid to begin with.

Re: Are oversized valves really needed?
 

I will try to answer your questions based on my engine experience and my dyno tests.
1) Will I get more horsepower with large valves? Only at higher RPM and then only if you have more carburetion.
2) What machining is involved? Cut a larger seat in the block and enlarge the passage directly below the valve. Not difficult for an engine shop.
3) Will a touring cam make standard valves perform better? Yes...the touring cam will provide more lift and typically a different profile or duration. The engine will produce more HP. Touring cams will allow larger intake valves to add a bit more HP...if you have a larger carburetor and intake again most noticed at higher RPM.
4) Are adjustable lifters recommended when using the oversized valves and touring cam? Yes for the touring cam for the following reason: When using a touring cam the lifter base diameter should be larger than a standard A cam requires. Many lifter bases are about 1.00" Some are close to 1.20" and these larger base diameter lifters are necessary for the higher lift cams. If you use the small base lifters (1" or less) with a higher lift cam, the cam lobe contacts the lifter close to the edge and promotes premature wear. The single-lock lifters manufactured by Colony have the larger diameter. See the photos below:

Lifter pictures: The Colony brand of lifters in single and double lock are shown below. I have purchased the Colony brand from multiple national vendors. The single lock base diameter is about 1.180". The double lock base diameter is slightly under 1" (.998").

Re: Are oversized valves really needed?
 

Jim Kroeger ;

About 25% of the folks in our club have the touring set up as you describe, me included .The other 75% have stock engines and no over drive . When we all go on a tour we run max 45 mph . to keep the stock members happy . Note all these modification will improve performance with one requirement,higher RPMS for an engine designed to be a low RPM engine .

Re: Are oversized valves really needed?
 

Jim, we've bit the apple too on an engine rebuild and are adding oversized intakes and a Stipe cam to your package. My goal isn't the freeway but climbing a hill or two far North of Fla. I cant do the work so Larry at South Florida Crank and Machine in Lake Park will do the job. Good Luck.

Re: Are oversized valves really needed?
 

"When using a touring cam the lifter base diameter should be larger than a standard A cam requires. Many lifter bases are about 1.00" Some are 1.12" and these large base diameter lifters are necessary for the higher lift cams."

Wrong and wrong!!!!
I don't know what lifter diameter Bill Stipe designed his cams to run on but I would venture to say that most all of the regrinds done by other people were designed to run on a 1 inch lifter. We run cams in model A's with .415 lift on 1 inch lifters.
If a cam is designed to run on a 1 inch lifter it will NOT catch on the edge of the lifter. A larger diameter lifter face will work but is definitely not required.

"Been in the cam business 60 years"

Re: Are oversized valves really needed?
 

If you look at all the performance enhanced or modern engines you will find they either have a large intake or in the case of multiple valve engines more intakes. Engines are air pumps and need to breathe, that's how to build HP.

Re: Are oversized valves really needed?
 

According to Vince Falter's FordGarage, Stipe cams require lifter base diameter of 1.117 except the B grind which requires 1.187. The point is check with your cam provider for the required lifter base.

Re: Are oversized valves really needed?
 

Here is a link to Vince Falter's web page where you can learn all about Bill Stipe's new USA made, Model A performance camshafts, with mention of the lifters required for use with these cam's. Thanks Vince !

http://www.fordgarage.com/pages/stipecamshaftspecs.htm

Re: Are oversized valves really needed?
 

Building a car where you need the last 3-5 hp at 2800 rpm? Put in 1.75" intakes. Building a strong driver for 'touring'? You'll never notice them. Put in a B (or Stipe IB330) cam and a police (large B) or Snyder head. You would never feel the oversize valves in the seat of your pants. They would only make a difference in a timed event like a hill limb.

Re: Are oversized valves really needed?
 

For touring purposes I have found that the Snyder 5.5 or equiv. HC head, plus an overdrive, will give you 90% of what you need....55-60 mph will not be a problem, and the engine will run much quieter and easier than trying to push a stock, re-built engine that fast, which very few do. I also added the V-8 clutch and pressure plate, lightened flywheel, and an Aries muffler. I still have stock cam and carb, and my TS runs very well, and is still simple to work on. Once you start down the road further you might as well add a Weber carb in addition to all the other stuff, and not sure you need to go that far, unless all out Model A power is what you are looking for.

Re: Are oversized valves really needed?
 

Pete, You may be right and with 60 years to back your opinions I am not going to argue the point. But let me clarify that I did not say the cam lobe would "catch on the edge" I said "the cam lobe contacts the lifter close to the edge". I am basing my opinion and statement on Bill Stipes recommendation of suggested lifter base diameter. Since I use Bill's cams...I will follow his advise. (If I want the warranty support of a manufacturer, I best follow his advice.) I should have referenced the use of Stipe cams. (Check out the link in Post # 17 above for Bill's written statement.) Everyone else is free to make their own choice and if they use your cams they can choose lifters accordingly. Thanks for your input/correction Pete!

For a study of the required lifters to use with a stock B grind check out the link below.
http://www.fordgarage.com/pages/valv...comparison.htm

Dave Gerold