Flathead Combustion Chamber Cut-a-Way

Thanks for sharing your work with the HAMB

 

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What a Fantastic Christmas Present,

Flathead Insight.


Bar none, I vote this into the Top Flathead tech category of the year if not more,
Thanks for all the hard work and research,
Cudos,

and Merry Christmas.


Ho Ho Ho and then some
moe




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Thanks for going to all that trouble to give us an insight of inner differences and pit falls of a flatty. It's nice to be able to see the cc,water jacket,cylinder bore and valves. This is great reference material.

 

My eyes are opened thanks.

 

The difference between a crack here (even if it does eventually find its way to the exhaust port) and one in the combusion chamber is one of pressure. Obviously, the pressures inside the combustion chambers are extremely high compared to the pressure in the water jacket. Conversely, the pressure in the exhaust ports is not likely to overcome the restriction of the crack since it has an easier path to go through - out the exhaust port. It will take the path of least resistance & not past the (sealed) bolt, through the crack, into the water jacket.

I feel these cracks are still relatively harmless even in light of where they may end up.

The cylinder wall pitting is always a concern and a gamble one takes when going with large overbores. Can you measure the average cylinder wall thickness & let us know what it is, as well as what the bore is? Your block appears to have minimal core shift and might be a good "average"

 

Great Post. Merry Christmas to all.

 

Okay Flat Ernie, you convinced me not to worry about the center bolt hole cracks and I used dial calipers to check the cylinder wall thickness at random places missing the pits that you requested. Picture below and thanks to all for posting the positive remarks.



Vergil

 

Vergil - awesome! At .080" over already, the "standard" .125" overbore is .045" more leaving the thinnest spot (.150") at .105" - well within accepted standards for modern engines that see a bit more stress than our beloved flatty! Good to know.

Of course, the pits make all those numbers meaningless....that's why my next engine is starting with a new French block!

 

Vergil
I noticed in the first pic that you also cut and exposed the intake ports on the other bank.
I was getting ready to do this (sometime in the next 10 yrs.) as I want to build injector blocks to mount there.
Could I possible beg and plead for some pictures and measurements of that area?

Thanks
****

 

Will do ****, I figured I might as well cut the intake ports to check how much room there is to fit fuel injection into the ports. Not much room for sure. The smallest injectors I could find were the side load Nissan injectors unless you use a stubby injector but the ones I saw put out to many #hr. I am working on the blocks now to see how they will fit on the junk motor. I will get you the info you want tomorrow. I can PM you or post if anyone else might be interested.

Vergil

 

Thanks

I would say to post it, we may as well get other minds thinking about this.
****

 

Does these pictures show what you need ****?







I drilled a couple of holes to check the block thickness where I will be drilling and taping for the injector blocks.




A picture looking through the intake port at the injector.





If you need other pictures that might help let me know, I'm not a machinist or guru but just a typical guy that likes to help if at all possible and hopefully others can post additional information to help also.

Vergil

 

These days I'm far from either a machinist or a guru - but I am a hell of an imagineer.
Those are great pics - really like the one looking from the inside out at the injector tip.
I know optimum is a straight shot at the back of the valve - but anything (almost) is better than a 90* bend.
Thoughts on the injector block ~ angle the side that the injector mounts maybe 20-30 degrees and taper the hole on the block side.
I just tried drawing what I was saying and my muscles arn't cooperating - looks like 2 yr old with an etch-a-sketch.

 

I just saw this pic on another post here.
It's the Flatfire Motor.
It has a radical cut to expose the inlet tubes.
Just thought I'd throw this in to keep the minds turnin'

 

I like the position of the injector in that second picture.
That should give a super spray pattern and get a good mix with the air being drawn/pushed in.
Something like this with a good ECU and the right sensors should make tuning and driving a real nice expierence.
You could run about any manifold up top and run the carbs as throttle bodies - hey I could even run an 8 Carb setup and have 6 of them blocked off.

 

Here is an engine on eBay that did not meet the reserve - it uses the 'injector block' concept that you guys are talking about. He's done some nice work - and actually the motor was not a bad deal if one was looking for something like this and had the $$$ to spend.

Here is is:



http://cgi.ebay.com/ebaymotors/ws/e...0290497541&sspagename=STRK:MEWAX:IT&viewitem=


Might be worth dropping the guy an eMail . . . if you need more info.

dale

 

That is a nice setup, took your advise and asked if I could impose on him for a couple of questions.

Vergil

 

Dale

Thanks - I have only seen one pic of this setup with no other info.

I think it has got to be one of the best EFI setups out there based soley on the injector position.
Vergils already running the electronic end of this on his motor already - Ain't he smart

****

 

Vergil, I watched a video slo-motion of a sequential timed port injection engine. It looked like the fuel injector fired it's shot soon after the spark was going off. This resulted in a cloud in the port right near the valve. When the valve opened, the cloud went in first followed by a slug of clean air.

I mentioned this to add that maybe the injector placement and angle is not that critical.

Thanks for posting the pictures.
It looks worse for flow than I thought. I would be removing metal on the back side of the valve (more of a T than a Y) and making the head diameter as small as possible, moving the seat out as wide to the edge as possible to help the air. Unless this is just for a cruiser engine, then, nevermind


Great Tech!!

 

Thanks for the input gas pumper, that would be a nice video to watch, didn't realize that was the sequence, thanks, good to know. I have Manley proflow SS valves that have the undercut stem and the tulip part is thinner than the ford. It will be a street engine but I like the extra oomph still. This type of information is great to know, dough heads like me need all the tech information we can get because of our limited R&D with the flatheads but a lot of trial & error experience on a limited budget.

Vergil.

 

Virgil: Are you planning a sequencial based EFI or batch? Can the ECU you're running operate in either mode? Also - are you NA or supercharged? I was pondering setting up a "mule motor" this winter (blown) - using the FAST XFI controller . . . am interested in more details of what you have cooking on your end.

Thanks!

Dale

 

For what it's worth:
In reading up on and talking to some who are running true port injection very few are true sequencial injection.
Some ECU's will support sequential injection at idel and up to the low mid range then switch to batch fire for the rest of the way.
Several reasons given, slow processors, not enough memory, legnth of intake runner (At higher rpm the charge can't travel distance in time given/required)..
There are a few aftermarket ECU's claiming to now or soon to support full sequential injection for limited applications (Not specified). With a Flatmotor configured with the injectors as above and an intake like Hilborns original or a blower supplied air source it may be possible to run true sequential port injection that would be street/strip compatable and not require six hands and two uncles to tune.

 

Dale on the flathead in my '31 coupe I am running 4x2's (junk 94's that have been gutted and bungs installed in 2" risers. The injectors fit up into the fuel bowl which hides most of them. The intake has the 3/4" equalizer runners between each port so it is not a true injector per cylinder even though I have eight injectors. I am using the Electromotive Tec3r ECU set up as full sequential, the old distributer is gutted with a hall effect sensor reading from a disk mounted to the distributer shaft. It runs good but I am not happy with the equalizer runners between ports. I have another 4x2 intake identical to the one I have running but on this intake I have blocked off the equalizer runners for a true port per cylinder injection. The tricky part I think is setting it up due to the poor vacuum with the port per cylinder. I think I have it figured out on where I will pick up the vacuum from and still hide as much of it as I can. This is my winter project in fact worked on it some today. The hidden injection I am working on will be for the engine being checked out at the machine shop now and using the 4x2 manifold with blocked port runners.

Vergil

 

Thanks for the info and effort guys.

 

Very interesting. Thanks from me too.

 

Hey Virgil: If you are going to be making the aluminum injector blocks, then you might consider putting a vacuum port in each of them and bring all 8 ports to a 'vacuum manifold' - which is where you'd hook you ECU up to.

This would give you the benefit of creating a combined vacuum signal -- all hidden in the lifter valley. I'm not an expert it EFI, but have been doing quite a bit of reading on custom systems and design -- want to convert a 2-port and 4-port Hilborn blower injectors over to EFI.

 

Just thinking with my fingers here.

With the EFI/ECU the "System" doesn't require the actual vacuum to open/close a valve - it only needs to read a change in vacuum on a MAP Sensor.
Running small lines to a 3/4" tube with a MAP tapped into it would fill the bill.
If you needed actual working vacuum for other systems you could use an electric pump and an acuumalator.