Self/repair & rebuilding my "G" model flathead SIX

[Vintage Copper 47]

I am considering taking the plunge and doing my own re-build of my early 1947, 226 C.I. "G" model SIX cylinder motor. I know many questions will come up through this. My first questions are:

1. Harbor Freight (I know, china crap) has a folding version motor stand with a 2K capacity.. Would this be best or are there some tricks to bolting up flywheels/clutch assemblies & having the flexibility to invert the motor for oil pan, etc. or any other manufacturer suggestions?

2. I have started collecting the rarer parts (water pump, distributor, etc.) but what about the starter? I read somewhere I need one with less teeth because a SIX cylinder flywheel is different than a V8s.?

A post on FORD SIX PERFORMANCE read:
the drive gear must have 9 teeth to correctly mesh with the 6 cylinder 114 tooth ring gear.

Whereas the V8 has the 10 tooth v8 drive gear which meshes with the 112 tooth v8 ring gear. The v8 ring gear will not fit on the 6 cylinder flywheel.

Even if I have a shop rebuild my motor, I am considering doing a rebuild on another "donor" motor to get the experience. "I guess I am old enough for the experience & too young to know better"

Thanks in advance for any advice you can give me..

[GB SISSON]

Walt, I have built 6 or 7 engines in my home shop. All Flathead V8s, and the process was never without a certain amount of apprehension. I Have had minimal machine work done and have measured a lot of assemblies very carefully. I have the Ford Motor Company 'repair manual' for the '37-'48 V8 engines and follow the procedures religiously. The forward in this manual states
"This is a Repair Manual rather than a Reconditioner's Manual, and some acceptable repair practices would not be acceptable reconditioning practices, In this book the word "repair"is used to indicate "restore to good working condition" and not to a "like new condition". That condition is good enough for me and how I use and drive my trucks. We have a couple of things not available to folks working on their ford engines back then. In order of importance to me:
The internet (vast knowledge of fordbarn members)
Plastigage
Ball hones
adjustable lifters
Excellent modern oils

I highly recommend the adventure!

Oh and you are correct on the ring gears and starter gears. The ring gears for the six are extremely hard to find, but Al Suehring in Upstate NY sells just ring gears. He recently did a run of six cyl ring gears and I bought one. He's on the 'net.

[flatheadmurre]

Starter base is the same just the bendix that is different.
Distributor body is the same to just the breakerplate and missing a couple of cylinders on the cam...so many parts interchange if you break them apart.
You didn´t consider rebuilding a H core ?
Full rebuild kit for an H is still available and around $1200.

[FortyNiner]

I recently completed the rebuild of a 59AB V8. While clearly not the same engine, my level of inexperience likely matches yours. A couple of takeaways :

It can be done!

GB's comments are spot on.

A couple of references that helped immensely for basic process info:
Rebuilding the Famous Ford Flathead by our very own Ron Bishop
Ford Flathead Engines - How to Rebuild and Modify by Thacker & Herman

The HF lift is very serviceable. A lift plate and leveler are suggested.

A sturdy table to hold the block during the disassembly /reassembly. I slapped something together that mostly worked.

My space was limited and my profound ignorance kept me away from an engine stand due to fear of damaging the funky bell housing on the 59AB. Turning the engine was an issue for me. I solved it with brute force and a mildly alarming disregard for personal safety. You may want a more sensible solution.

The machine shop installed the adjustable valves for me. This greatly simplified my tasks. May be a path for you also.

If you don't have the shop install the crank, have them clean the yokes. Since I now know about the need for super clean parts for assembly, this may avoid one of my redos.

Having access to the brain of a more experienced mechanic was critical. Just being schooled on basic shop practice for cleanliness, measurement rigor, and process mattered.

Plan on spoiling at least one rope seal and getting the assembly order wrong at least twice.

Two words: Assembly Lube. 'Nuff said.

Enjoy the journey.

[rotorwrench]

The rear clutch housing is removable on the G series 6-cylinder but can be left in place if you want to use a turn over stand. The turn over stand make life easier during reassembly but it is not necessary for cleaning or machine work and that may necessitate removal of the rear housing.

Pistons, bearings, oil pump, and possibly other items are getting harder to source but persistence pays. Check with the NOS parts guys as soon as you have an idea about what you will need. Southside Obsolete (barnfind08 here on the barn), has a lot of hard to find stuff.

[amodel25]

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Watch e-b** for a nine tooth bendix. I've found two of them. Kanter still lists some G overhaul parts in their catalog.

[Vintage Copper 47]

Thanks for all the advice.. I am going to rebuild the "G" model and temporarily put in the H because of the problems I have heard the H has with loadamatic distributor.. I also have all the "core" parts needed (water pump, distributor, intake/exhaust..) By the way, my current motor is still running and still in my 47...just doing all the research/prep/parts gathering in advance.. My current motor has a rod knock & some piston slap (broken rings?) & with needing a new oilpan gasket, I figure if I have to pull the motor to fix oilpan, I might as well do the rebuild.. Which brings me to question no. 3

Question 3 the reason I have to pull the motor to change the oilpan gasket is primarily because the crossmember is in the way (riveted to the frame).. After I pull the motor, is it recommended that I take out the rivets & bolt in the crossmember, making it easier for future oilpan gasket replacement? Like I said before
"I guess I am old enough for the experience & too young to know better"

Thanks again, WALT

[GB SISSON]

Bolts are good in so many ways. Rivets were probably fast and cheap on the assembly line. Not to say they don't hold like a sonofagun. I don't think I've ever seen one getting loose.

[rotorwrench]

Rivets were and still are best long term way to hold a frame like that together. The rivet fills the hole tightly during the setting process. Bolts fit loose enough to push them through by hand. A tight fastener will stay that way longer. Once it gets loose, the quicker it gets even more loose. These old frames move around in twist and bend more than most folks realize. A loose fastener will make an elongated bolt or rivet hole pretty quick in rough conditions.

In aviation, many bolt holes are machined to close tolerance and a close tolerance bolt or pin fastener is installed. When they get loose, some have to be reamed for the next size or next oversize if one is available. It's either that or replace the whole assembly.

[Vintage Copper 47]

Originally Posted by rotorwrench

Rivets were and still are best long term way to hold a frame like that together. The rivet fills the hole tightly during the setting process. Bolts fit loose enough to push them through by hand. A tight fastener will stay that way longer. Once it gets loose, the quicker it gets even more loose. These old frames move around in twist and bend more than most folks realize. A loose fastener will make an elongated bolt or rivet hole pretty quick in rough conditions.

In aviation, many bolt holes are machined to close tolerance and a close tolerance bolt or pin fastener is installed. When they get loose, some have to be reamed for the next size or next oversize if one is available. It's either that or replace the whole assembly.

I get that ROTORWRENCH.. I just wanted to make things easier.. perhaps I can add additional reinforcing braces in front of or to the rear of the motor & still have the ability to pull the crossmember for oil pan issues.. the mechanic that rebuilt my transmission took out the rivets and put in bolts so he could pull the trans from below instead of through the floorboard.. and I am not planning on any pursuits.. LOL just a thought..

[GB SISSON]

For us, on good roads (well, most of you guys) we won't torture these things like in the past. A few bolts swapped in won't change things much, but seriously a rivet swelled up in the hole is still a tough customer to deal with. I just changed out 4 running board braces, 16 rivets last weekend. Rotorwrench knows what he's talking about.

[Vintage Copper 47]

Originally Posted by flatheadmurre

Starter base is the same just the bendix that is different.
Distributor body is the same to just the breakerplate and missing a couple of cylinders on the cam...so many parts interchange if you break them apart.
You didn´t consider rebuilding a H core ?
Full rebuild kit for an H is still available and around $1200.

So I found a complete running "H" model motor from a 48 F4 truck.. I want to do an engine swap out.. anybody have info as to problems I may encounter?

I realize that the motor from the truck MIGHT have a large diameter clutch? possibly a 10" inch clutch compared to a "9" inch clutch on the sedan.. That being said, if true, can I swap the clutch & flywheel from the other motor to the H model?..

ANY & ALL advice you can give me would be great! WALT

[Bob C]

An F4 would have an 11" clutch.


Bob

[flatheadmurre]

Flywheel could be redrilled to accept your 9" if it´s in good shape.

[Vintage Copper 47]

Originally Posted by flatheadmurre

Flywheel could be redrilled to accept your 9" if it´s in good shape.

Or could I swap out the flywheel?.. especially because my G model motor may have the different ring gear on the flywheel?

What say experts?

[41Joe]

I'm no expert, but when I installed the H into my 41 I had the flywheel from the existing V8. It fit just fine. I used the starter from the V8 also. So far I haven't had any problems with it in the past year or so of driving it.

[Vintage Copper 47]

Originally Posted by 41Joe

I'm no expert, but when I installed the H into my 41 I had the flywheel from the existing V8. It fit just fine. I used the starter from the V8 also. So far I haven't had any problems with it in the past year or so of driving it.

I will count the teeth on the ring gear of the 48 "H" model.. if it is same as my "G".. then I will just redrill the flywheel to accept the smaller clutch!

[Vintage Copper 47]

Originally Posted by Bob C

An F4 would have an 11" clutch.


Bob

Originally Posted by flatheadmurre

Flywheel could be redrilled to accept your 9" if it´s in good shape.

So... I was thinking.. I have the entire clutch cover & starter to the "H" model SIX that I just picked up in Arizona. Will the bolt pattern for the cover match the bolt pattern to my sedan transmission? If so, could I just leave the 11" inch clutch/flywheel combo with attached starter on the "H" motor & hook it up with my 47 transmission? Are the splines different number or longer with the truck transmission? I have the entire motor intact with the trans, I was hoping I could bolt the whole thing in.. What say you Fordbarners?

[flatheadmurre]

It will bolt togetter.
An 11" clutch may be a bit tough compared to what you´re used to...but will pull any camper you can hook up to the -47 just fine

[JSeery]

It depends on you liking the feel of the 11 inch and your concerns about performance. The 11 inch will feel like a heavy truck clutch, and the performance will be in that range as well. If you are happy with that, then ok, if not redrill it for a 10 inch or 9 inch.

[Vintage Copper 47]

Originally Posted by flatheadmurre

It will bolt togetter.
An 11" clutch may be a bit tough compared to what you´re used to...but will pull any camper you can hook up to the -47 just fine

Originally Posted by JSeery

It depends on you liking the feel of the 11 inch and your concerns about performance. The 11 inch will feel like a heavy truck clutch, and the performance will be in that range as well. If you are happy with that, then ok, if not redrill it for a 10 inch or 9 inch.

Sounds good to me! ... That way I can do an even swap.. then tear down the original "G" model motor for a complete rebuild.. after that, I can put the original motor back in the car to keep that originality! Thanks for the advice!

[Vintage Copper 47]

Originally Posted by flatheadmurre

It will bolt togetter.
An 11" clutch may be a bit tough compared to what you´re used to...but will pull any camper you can hook up to the -47 just fine

Originally Posted by JSeery

It depends on you liking the feel of the 11 inch and your concerns about performance. The 11 inch will feel like a heavy truck clutch, and the performance will be in that range as well. If you are happy with that, then ok, if not redrill it for a 10 inch or 9 inch.

THANKS GUYS.. I have the "H" model on the engine stand.. but it seems way too front heavy, even though I tightened up the adjustable brackets, I get some extra flex & I had trouble lining up the holes to the clutch cover.. SEE Photos! Is there a better source for an engine stand or cradle style I could use that supports more of the weight? I got so concerned I re-attached my engine crane to take up some of the weight but I don't plan to leave it that way and cause undue stress the the bottle jack on the engine crane/hoist! Anybody have suggestions? Need some fordbarn expertise for a vendor source/solution to my problem!

[40cpe]

You can help by removing the clutch housing and flywheel and bolt the block to the engine stand

[Vintage Copper 47]

Originally Posted by 40cpe

You can help by removing the clutch housing and flywheel and bolt the block to the engine stand

Yes, I considered that 40cpe.. before that, I was going to remove all the accessories. I will also have to remove the starter.. I have always dealt with GM starters, so I am afraid when I remove it it will come apart on me!

I was just considering other options, I want to be able to do a run-up & test this motor before I do the swap..

[Vintage Copper 47]

Also, I am looking for input on the Pros & Cons of keeping the H motor instead of the G.. for instance, the front crab distributor is fairly maintenance free (no timing adjustments to speak of) But how about the H motor "Loadamatic"? Is it capable of performance increase or replacement with a mallory?
I read somewhere that you can weld a gm style distributor to a ford shaft.. Or am I getting too far ahead of myself.. I will email Jim at Bubba's Ignition for the best advice. Basically, I want to build a motor with slight performance increase but with the reliability I currently have..

[flatheadmurre]

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You can adapt basicly any "normal" style distributor to fit by turning down the shaft and mounting the ford gear on it.
The HEI might be good performance...but they sure aren´t pretty in a nice original car.
I usually take a compact accel or similar and adapt it...you get same performance and points.
Cut down the head of the H to raise compression that will give you increased power and mileage.

[Vintage Copper 47]

Originally Posted by flatheadmurre

You can adapt basicly any "normal" style distributor to fit by turning down the shaft and mounting the ford gear on it.
The HEI might be good performance...but they sure aren´t pretty in a nice original car.
I usually take a compact accel or similar and adapt it...you get same performance and points.
Cut down the head of the H to raise compression that will give you increased power and mileage.

Thanks, that's the kind of info I was looking for!

[Vintage Copper 47]

Ok.. I was taking a closer look at "H" motor on the stand.. And I noticed what looks like a weld/repair to the rear of the block at the intake/exhaust.. I haven't cleaned it up as yet.. Is this a terrible problem? I am not worried as I have a source for another block.. just wondering if should strip the motor down & pick up the 2nd block... The crap we find when we look closer at things..