Technical Flathead Porting: Soup to Nuts . . . Pictures, Details and Opinions

Got my target to the tune of a 13.398.

 

this is a great thread ......

 

I agree. Great thread and glad to have something to bring it btt.

CNC carving combustion chambers. "barrel shape" as mentioned earlier in this thread. Did a bunch of flow bench testing on chamber shape.



Flat32

 

Thanks for sending me eMails of all your progress/results from racing - you've made unbelievable strides in your designs. Do you happen to have some completed pictures of your chamber designs - to show the m***es? It is not for me to share, so I thought I'd just ask! Also, maybe what valve sizes and cam patterns?

Anybody who is really interested in what folks can do with a LOT of design work, testing, casting, dyno, racing, etc -- just checkout what Ray has done on the links above, extraordinary work!

Take care . . .
B&S

 

You can still buy big port intake gaskets from Baxter Ford Parts in Kansas either for $12 or $14;just bought some about a month ago.I would be willing to "loan" out my homemade 2/2 tunnel ram for someone to try it to see if it "works"; looks good on paper,but needs to be tested! Give me a call if interested flatheadjohn47 Texas 979-595-7324 cell.

 

Bump please, heavy research going on here.

 

Been a while since this was near the top. Bump so I can find it again soon. Gonna have my buddy write a program to trim the tops of guides in his CNC lathe. Also hope to line a pile of used guides since trustworthy new ones aren’t common.

 

Good thread, cant believe its been over 10 years since I last posted.

 

Hey you bunch of Flathead nuts . . . good to see the revival of the half-dead! The good news is that I just got home from running around with my 32 Cab (very heavily ported of course) with my friend Andy who I helped build his 302+ inch flathead (heavily ported of course) and these two cars/engines are so much damn fun. This is like being a 7th Grade kid and seeing your first pair of . . . yeah, those! LOL

 

Thank you for posting such a wonderful, informative thread.
Solid gold that never gets old.

 

I was poking around on the Manley website last night and they have a myriad of 1.5 valves with different stem diameters. Any tried and true part numbers that would work with a SBC sized guide liner? Don’t want to have my machinist buddy buy new reams and tools just for me. What kind of clearances are needed on the valve stems for intake and exhaust?

 

Manley 12342-8 Manley Severe Duty Series Stainless Steel Valves | Summit Racing
SBC Manley Severe Duty Intake Valves 1.720, 4.911 length, .3415 stem diameter (which helps with high lift flathead cams - which have smaller base circles, so a longer valve takes up some of the "slack". Since these are intake valves (not 1.6" exhausts), they have a nicer profile in the heads and are not as thick as the 1.6" exhaust valves that everybody runs.

I put 1.750" hard seats in the block - SBI Part # SB1750. In order to do this you have to have the tools/shop remove the old seats and bore out the valve seat pockets and use about a .005 or so press fit.

There are plenty of racers that just remove the intake seat all together and grind the seat right in the block. This works just fine!

 

You guys will enjoy this exchange . . . given the eMails I received from a guy all aggravated because I didn't provide every last detail related to cams, valve height, etc:

First eMail I received:

While your article on using Crower Valve Retainers on a Flathead was very nice, you have caused me untold amounts of grief and aggravation by not letting readers know ..... You ABSOLUTELY have to machine off about .250" off your lifter bores, or you'll NEVER get in that tight space to adjust your valves !!!!!!!! Please add that to your article. Oh yeah, your calculations for the amount of Valve Spring Shims was WAY OFF, even using the Crower Retainers on SBC High Flow Valves !

My Reply:

Well, sorry to hear that you've had some drama with your setup. The issue with machining your lifter bores is due to the length of your valves and the lift of your cam - it has nothing to do with the valve spring retainers. Even if you used STOCK retainers, you'd have the same issue. So, before you decide to sling a bunch of **** my way, you should really think about what is going on!

1) With a higher lift cam, the base-circle diameter of the cam has been reduced --> this causes the valve lifter to DROP further down the lifter bore. The higher the cam/valve lift, the more it drops. This makes the lifter adjustment head/screw drop down into the lifter bore as well . . . which makes it hard to fit in a thin tappet adjustment wrench. You'd have to grind the lifter bores no matter which retainers you used. This is common knowledge with folks installing high-lift cams in flatheads. The fact you didn't realize this is not my issue.

2) I have never told anybody exactly how many valve spring shims to use and I didn't provide you with any calculations! I can't possibly know the installed valve spring height of your particular setup - it depends on the valve seats, the valve lengths (non-stock), etc.. I've always said that you need to have the springs checked by a machine shop to determine the installed height and then you'll put the necessary amount of shims in as such.

3) The fact that you are using LONGER than stock valves means that more shims would be needed than if you used stock valves. But, using stock valves can cause the lifter adjustment screw to be further out in the lifter and this may cause the screws to be looser than needed to hold the lash.

4) If you believe my article is incorrect - send me a link to the post you read and I'll add additional information . . . information that anybody putting a high-lift cam and longer SBC valves needs to know - regardless of the retainers used!

Second eMail I received:

It's your half ***ed, incomplete article; Flathead Porting: Soup to Nuts 2. You better go back and read it again.Your " Common Knowledge" comment proves you are a Horses ***. There's so many young folks out there that would like to enter the World of Flatheads, but half information, and smart *** comments show you are just another hack who likes to see his name on a PC or You Tube site.

My Reply:

XYZ, maybe I was a little harsh in the start of my reply, that I apologize for, but the information I gave you and the technical reasons behind it are 100% correct. You seem to have a bone to pick with me - and seem to love to throw insults my way.

There isn't one piece of information in that multi-part thread that is incorrect. If you had issues with what I wrote or needed additional information for your build, all you had to do is ASK some questions -- there are plenty of folks (including myself) that would have helped you. Instead, you throw insults and take out your frustrations from lack of knowledge or experience on somebody who helps folks for no monetary gain. Maybe you should step back and rethink the at***ude you're bringing to the table?

Given that I'm a Horse's ***, here is a paragraph from an article that Mike Bishop did that denotes the issue with big cams, small base circles and lifter bores. Maybe you should look him up and call him a horse's *** as well.

Best of luck with your build.

D

MODIFYING THE LIFTER BORES

When stock Ford camshafts are reground to alter valve timing and increase valve opening durations, the height of the lobes and the diameter of the base circle may be reduced by something approaching 1/4 inch. The adjuster bolt in an adjustable lifter, takes up the resulting slack when it's time to open the valve, but the lifter body sits lower in its bore in the block. During valve adjustment, when the lifter is sitting on the heel of the cam, the lifter is at its lowest position, and in this position the top of the adjuster bolt is often flush with the top of the lifter bore, making it difficult to fit a wrench to the adjuster bolt.

The solution is to cut a 1/4-inch relief into the top of each lifter bore to expose the adjuster bolt head enough so it can be reached with a wrench to adjust valve clearance. Then, a 1/8-inch hole is drilled into each lifter bore, just above the camshaft oil gallery tube, so that a length of steel rod can be inserted to prevent the lifter from turning when the adjuster bolt is turned.


Some folks . . .

 

Wow. Guess what everyone... modifying things is a slippery slope, and you have to do your due diligence if you want to get it right!

Dale... when does this book go to print? Not the disgruntled individual's comments, but the good stuff, rather...

3blap.

 

Touché mon-amie(or something like that...) .
I like your writings.
Marcus...

 

And this is how the LS swap was born

 

Is there enough Material , just to remove
The valve seat and use a 1.75 intake valve ?
In the block ?
On the other hand is there enoiugh material to
Install a bigger seat for the 1.75 valve , or will it
Weaken the block ?

 

I read somewhere that guys have used EAB blocks for this since they do not have valve seats. The valve pockets were cut right into the deck of the block. No hardened seats on intake or exhaust. I think they were '53 only.

 

Very informative work for rodders that want more than a standard Henry v8/I have built,bought,sold,drag raced flatheads for 60+++ years but never had the “knowledge” to take advantage and really understand what works and how to make an old design “perk up” and make believers out of the naysayers. The only thing I did differently on a street flathead was to relieve only on the INTAKE SIDE approximately .080-.090; thinking it relies on suction and leaving the EXHAUST SIDE alone since it is expelled from the block under pressure and still leaves a little bit of compression in the block. All my flatheads ran strong(had a heavy foot and destroyed many early gearboxes) and back in the late 60’s ran Muncie 4 speeds and a 9 in rear, knowing the flathead would not do damage to these pieces. Nothing like power shifting a Muncie at 5500 to second gear and having the tires break loose. Had a street Anglia that ran 14’s at 93 and a Henry 32 cabriolet that ran 80 in the 1/8—both were flathead street cars that ran strong. FLATHEAD FOREVER!!!

 

I use 1.72" intake valves with new hard seats installed. These work out just fine and you're not going to gain anything going from a 1.72" intake to a 1.75" intake. Further up in this thread I list the seat part number that I use and the ***ociated Manley intake valve that I use. You'll find this combination works really well. Some guys knock the seats out of the blocks and just perform a valve job on the cast iron, but I like having a hard seat installed for a high-end street motor. Reason, I can always replace the seat in the future, while if I remove all that material and just use the block, there might not be enough left for a hard seat. (maybe?)

 

I Ment 1.72 Inch Valverde. Sorry.
I will Order the Seats
Thank you

 

Opinions? Put a blower on it and save yourself some work...

 

love all of this ,, real meat on the subject ,, keep it coming ,,, eagle crank or **** is my question to do a 296 hot street ?
fabricator john
miss you dad