Building a High Performance Flathead Ford Part 1 - Overview & Introduction
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- Опубліковано 8 вер 2024
- This video is part of a series describing the buildup of a high performance flathead Ford engine with Gary McGlasson of McGlasson Racing Engines and Joe Abbin of Roadrunner Engineering, both of Albuquerque, NM. See the other videos on the UA-cam "Blown Flathead Channel" at / @blownflathead or see www.roadrunnerengineering.com for more info.
I found that smoothing the ledge on the piston side of the head where the cylinder/valve area is, helps the engine idle smoother and lower rpm. That hard machined ledge doesn’t allow for a laminar flow of gases in the combustion chamber. The turbulence it creates hurts the engine performance.
I’m glad to put the face with the name! I love reading your articles in the Ford V8 Times! Thank you for all your expert advice!
Nice work on these engines!
Joe, you're the REAL flathead king! Your books are priceless and you have been very helpful when I talked to you on the phone many years ago. Thanks for myth-busting the flathead!
Really enjoyed your video. I am really excited about my flat head. And what we can do with it . For just a good solid engine
I moved to Albuquerque in late 2014 and this is interesting to know there are engine builder here that seem to be well known. Just not me till now. Wonder if anyone can tour the shop.
Send me an email at roadrunnerengr@msn.com with what you would like to see and we can discuss.
I bought a vehicle with a 8BA in it a couple of years ago so I am trying to learn about them. Thank you!
Mr. Abbin. I've enjoyed reading your book. I have two questions: 1) Do you still build flatheads for customers? And 2) At a car show two years ago I saw a flathead with four-tube headers on each bank. The two for the center port were cut and welded together and used a single flange for the center port. Have you ever heard or seen such a set up?
1) I do not do service work for customers any longer, but could possibly make recommendations if you email me.
2) I have seen the "siamesed" center exhaust system you noted. I would not expect any performance gain.
Relieving is a waste of time, and reduces the c/r. The inlet flow in a flathead is up, across the underside of the head chamber, and down into the cylinder- and vice versa for the exhaust. The block material between the valves and the cylinder is not of concern and does not effect flow. Just leave it alone, but make sure there is enough flow area in the head chambers over the valves for full flow at full lift. If not, the head chambers will need to be fly cut to deepen the pockets, and then smooth them into the head's flow area above the cylinder edge.
Rob, I used to believe relieving was not important until I actually started flow testing the flathead. You can read all about it in my book, "335 HP Flathead Ford V-8 Performance Handbook", pages 27 to 40. The HP difference with the increase in air flow far outweighs the loss due to the decrease in compression ratio. All record holding flatheads in the day were relieved.
As the piston goes down on the intake stroke, it pulls the incoming mixture down to the block surface and removing material here substantially increases flow even for large chamber heads.
@@blownflathead I should have clarified my statement. For a blown motor, relieving may be worthwhile? I have no experience with this. For naturally aspirated, I would respectfully disagree. Technically the incoming mixture is not being pulled into the motor by the descending piston, it is being pushed in by atmospheric pressure due to the vacuum created. Years ago I read an article about relieving, with flow test, written by I believe Barney Navarro? The conclusion was relieving was found to be unnecessary. That is when I stopped relieving my blocks.
Yesterday I pulled the heads on my 284" motor (getting her ready for next season) and inspected the head chambers and the block deck at the area from the inlet valve seats to the cylinder. Both heads, all 8 cylinders show a very clean mixture flow surface track right from the the inlet valve's cylinder side, across that side of the head surface to the area above the cylinders. Clean aluminum, no carbon. However the entire block's deck surface shows the same color between the inlet/exhaust valves and over to the cylinder edge- a thin uniform coating of carbon with no sign of mixture cross flow from the inlet valves to the cylinder edge. None! Zero! There is no mixture touching this area. My deck is not relieved. There is more than ample volume in the cylinder head pockets to flow all of the volume coming from the inlet valves into the cylinders- naturally aspirated anyway. My c/r is 10.5-1 with tight squish. Dual 97's on a vintage Edelbrock regular hi-rise intake, Literio L100 camshaft. The motor pulls like a locomotive to 5000, and surprises many.
Forgot to mention, my heads are NOS 59 series 24 stud Canadian Ford aluminum pieces C7RA 6050B, unmodified. Nice heads!
If you build a High Performance flat head Ford, max revolution must be a problem. To me the Y block is better. As I have only ever had one flat head Ford(1951) I never kept it long, so I am no expert, it could cruise at 75 no problem, on level road it could lug down to idle in high gear then pull away with not the slightest bog down, this engine deserves respect for its span of use, 1932-- 1953.. 9
We generally limit flathead customer dyno testing to 5200 rpm. My own engine is limited to 5800 rpm. The stock parts are tough, but the 3-main bearing crankshaft does limit safe operating rpm.
To what depth from the gasket surface of the head do you cut the valve pockets to ensure appropriate clearance for the valves with the Isky Max 1 cam?
About 0.4" should be adequate. How high the valves stick up above the gasket surface and their diameter can affect this. Check for clearance by temporarily sitting the head in place without a gasket using guide studs (leaving off nuts) and turning over the engine to raise the valves.If they don't hit you will have adequate clearance in service. If the valves raise the head you will know how much and where material must be removed.
How do you determine the optimal cam lift and duration for these engines? Is there a flow test for them?
Hi Ken, two of my books ("Blown Flathead" and "335 HP Flathead Ford V-8 Performance Handbook") contain many flathead Ford flow tests. The output of these tests can then be used as input for engine performance modelling including cam optimization. The books are sold out and out of print, but I am planning new releases. Joe Abbin
Joe,
I am looking for detail on the relief you did to the block between the piston and the valves. Can you tell me how deep the relief has been cut? Did you remove any material from the back side of the valves of just in between the valves and the pistons?
The relief is .100" to .125" deep and is concentrated between the valves and between the valves and the cylinder bore. There is some flow on the backside of the valves but not much especially with big valves, so not much benefit in relieving in that area.
I typically cut the relief about .12"-.13" deep between the boundaries of the head gasket I will be using and hand blend to the valve seats. That will get 90%+ of anything you could get by going deeper and leaves some margin for error. At the back of the combustion chamber near the valves I just break any sharp corners at the valve seat-block interface. I do open up the heads in this area to the gasket boundary.
How much effect does releaving the block have on compression ratio.
A typical relief lowers the compression ratio about .2 - .3 points, e.g. from 8.5 to 8.3:1. Breathing typically improves 15% with relieving, making relieving a clear winner for increased power. This whole subject is covered in detail in my book, 335 HP Flathead Ford V-8 Performance Handbook.
p[ease help me with my 8BA. Its mounted on a trailer so I can tow it to shows and high schools. It started blowing water out of #1 exh. I changed the head gasket and now all my water goes into the pan. I accidently broke the blind hole bottom off the thermostat. Could this be my problem?
It is not likely that the thermostat break has anything to do with your problem. You will have to remove the head again and inspect the gasket for proper installation and seal. Also inspect the head and block visually and follow up with Magnafluxing if necessary.
i am sure i have seen an after market oil pump and external oil filter, surely when you asking the engine to work harder ( ie the blower ) giving it the best lubrication available in the interests of long life reliability.
The 'splash oiler system was fine for a standard engine but for a blown flathead??
You are absolutely right. All flathead V-8 Fords since 1932 have had full pressure oiling systems. A parallel or bypass flow - type external oil filter became available as a factory installed accessory in 1936 and as standard equipment in 1946. Full flow oil filter systems are also available. Please see Chapter 8 in my book, "Ford & Mercury Flathead V-8 Identification & Rebuilder's Guide" for a more detailed description of the flathead oiling system.
All the dumb arguments about why we even bother with the archaic ,inferior design flat head... you have to be “ old school”...you have to have had one and hot rodded it to understand...!!!American ingenuity can over come design inhibitions...!!! NASCAR... to slow down the 200 mph stock cars, made all kinds of design restrictions such as no fuel injection, and push rods only...!!! You still came out with 6-800 hp and revs between 9000 and 10,000 rpms... !!!
Any way , there are some flat head gurus that have done wonders in normally aspirated ...and supercharged categories...!!! It just takes lotsa $$$$...!!! If NASCAR came out with a class strictly for a flat head racing class... not the old FORD engines ... but a high tech,purpose designed flat head as a technical challenge, roller cams, 5 main brg cranks, 8 port blocks...it would be a test of genius to see what you could come up with...!!!