Flathead advice and help needed

[Desoto291Hemi]

Hi guys,
I just got validated a while ago and was gonna post as soon as I could.
I have just purchased my first flathead and I’m trying to learn all I can.
It is a 49 Mercury,,,I should have it in a few days,,,and will begin immediately to disassemble and check for cracks and defects.
I plan to completely tear it down
Then take to my machine shop guys to mag and check for any problems.
From what I have learned already,,,it seems the most common places are the head bolt areas to the water passage openings.
The valve to cylinder openings,,,and the pan rail area.
What other obvious things should I look for.
Thanks for all your help guys,,,I will need it.

Tommy

[Ronnieroadster]

You have the possible crack locations correct But there is one more location for cracks the lifter/valve area the wall thats on the other side of the water jacket I have found cracks in this area on a few blocks most machine shops never mag check in this area.. Another area of concern is the buildup of sand type material in the water passages especially between the rear cylinders on both sides of the block. That material needs to be scraped out of the water passages by hand. Welcome to the world of Flathead fun good luck with your new project.
Ronnieroadster

[Desoto291Hemi]

Thank you Ronnie.
I will keep my eyes open all I can.

Tommy

[19Fordy]

Congratulations! Be sure to check and see if the crank has a 4 in stroke like 49 Mercs came with. Besides doing what has already been mentioned above, take lots of photos as you disassemble it. Be sure to mark all the bearing caps and don't interchange them. Also, save all engine parts and don't throw anything away. Hope you were able to get the Merc flywheel,clutch and pressure plate too. You didn't say what you plans are but, be sure to ask plenty of questions on the fordbarn BEFORE you jump in with both feet.

[JSeery]

A pressure test might be a better approach than just mag testing. A test plates are bolted on and air pressure applied to the water jackets. Pressure testing can locate cracks missed by mag testing alone.

[Desoto291Hemi]

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My plans are to do a complete rebuild and add some power at the same time.
Nothing radical,,,just a strong engine
As a matter of fact,,,I will just go ahead and lay out my plan now.

1.
Get the block serviced and see that it is good.
Bore it somewhat,,,,not to the max,,,just a good oversize.
Deck it and clean up all the machined surfaces.
I am not sure yet about relieving the block for more flow,,still reading up on that.

2.
Clean and check the crank,,,see if the journals are okay,,,service as needed.
Balance assembly after the rods and pistons have been weighed for the bobweight.
Use good quality bearings throughout the assembly.

3.
Rods,,,,clean and check,,,shotpeen for strength,,,,resize and check for any defects.

4.
Pistons,,,,,I want to use a good brand of pistons,,,not the most expensive,,this is not a racing engine,,,just a nice hot engine.
I don’t think I will use the 4 ring system,,,I believe 3 rings will be fine.
Being that the pistons will be a modern aluminum piston and will be machined with a barrel shape to fit better in the bore ,and not prone to a lot of skirt movement.

5.
The camshaft will probably be a nice Isky grind,,,not sure yet.
I have looked at some,,somewhere in the .365 range maybe,,,not sure ,,,still early.
I would like to use the adjustable lifters if I can,,,,is that a good idea,,,I have just began to read about them.

6.
Valves,,,,,I would like to use a good stainless valve to be safe.
I would like to go bigger than stock,,,if I can?
I am considering going with a1.625 intake if I can make it fit?
The exhaust would probably be a 1.57,,,,I am still in the thinking stage with this.
I know most engines always used a slightly larger intake being that the mass of the fuel and the air is not as great after the combustion cycle,,,,no fuel droplets in the exhaust.

7.
The heads,,,,, I am thinking about a nice aluminum head,,,with a better chamber shaped to increase compression. I believe that compression within reason is free horsepower.
The aluminum ones have added capacity for more cooling water flow and fins to increase the cooling ability,,,,especially after the shutdown,(act as a heat sink),,,to help remove heat from the deck surface?
Although it uses bolts right now,,I plan to upgrade to studs for strength .

8.
Intake,,,,still don’t have a good direction there yet,,,but I am just starting here.
I am thinking a dual carb or single 4 barrel,,,,,not a bunch of carbs,,,,too much to keep up with I think.

9.
Ignition,,,planning on adapting a SBC dual point distributor,,I like dual points and believe that it will work great. I have a nice Accel dual point,,and several others,,,just plan on the Accel at this point.

That is about as far as I have gotten so far,,,still thinking and studying my options.

I am still in the planning stage here,,,any ideas?

Tommy

[JSeery]

Some good reading material: Ol Ron's and JWL's books and some others I like.

JWL's book goes through modifications one at a time with dyno runs to see what works.

[Desoto291Hemi]

I just ordered some of those titles today.

Tommy

[JSeery]

Be sure JWL's is one of them!!

[Desoto291Hemi]

Which one,,, Is that the blue one?
I didn’t see that one,,,,I will have to find it.

Tommy

[V8COOPMAN]

Originally Posted by Desoto291Hemi

Which one,,, Is that the blue one?
I didn’t see that one,,,,I will have to find it.

Tommy

Yup...Arguably the best and most-informative out there. JWL=John W. Lawson. DD

[tubman]

Tommy,

It would be nice to know what kind of car this is going into. A fenderless Model A hot rod vs. a '51 Mercury sedan would probably need different cam grinds, at least.

Denny

[Desoto291Hemi]

Hey Denny,

Man I figured some guys from the Hamb were here too,,,,probably a lot I guess,,lol.

Well,,at this time I plan on a hot rod style of car.
You know I was working on my Desoto 291 Hemi,,,and I still Am,,,,but I got an opportunity for a Flathead,,,and figured I had better jump on it too.
This will be a project that takes a couple of years probably,,just to learn all I can and finance all the parts needed to do it.

Tommy

[tubman]

The reason I asked is that if you are planning on putting this engine in a relatively heavy car, such as a post war Ford or Mercury, you can't do much better than a stock "8CM" Mercury cam. When I put the '51 Merc in my '51 Ford, I had purchased an Isky MAX-1 cam that I was going to use. After a bunch of back and forth, both here and elsewhere, I decided to keep the stock cam. So far it seems to have been the proper decision. It's not a waste though, as I now have the MAX-1 in an engine I built to put in a "T" tub I have in progress.

[flatjack9]

Originally Posted by V8COOPMAN

Yup...Arguably the best and most-informative out there. JWL=John W. Lawson. DD

Look on Mac VanP'selt site

Look on Mac Vanpelt's site.

[mfirth]

Times 2 on what tubman says.....if you have an 8CM Merc cam in good condition...use it.
I think tubman is a Hemi man too, he knows his stuf. Have fun flathead'n !

[Desoto291Hemi]

Do most of you guys run two temp gauges being that the water does not mix between left and right banks?
In case a thermostat sticks on one side or one pump goes bad.
Because as much as it cost to build it,,,I don’t want to risk a failure!

Tommy

[JSeery]

On a stock setup there are two senders, one the controls the temperature reading on the gauge, the other one is an on/off switch that operates at a predetermined temperature. A lot of people use two separate gauges on a non-stock application.

[flatjack9]

The water does mix in the radiator.

[40 Deluxe]

Originally Posted by Desoto291Hemi

My plans are to do a complete rebuild and add some power at the same time.
Nothing radical,,,just a strong engine
As a matter of fact,,,I will just go ahead and lay out my plan now.

1.
Get the block serviced and see that it is good.
Bore it somewhat,,,,not to the max,,,just a good oversize.
Deck it and clean up all the machined surfaces.
I am not sure yet about relieving the block for more flow,,still reading up on that.

2.
Clean and check the crank,,,see if the journals are okay,,,service as needed.
Balance assembly after the rods and pistons have been weighed for the bobweight.
Use good quality bearings throughout the assembly.

3.
Rods,,,,clean and check,,,shotpeen for strength,,,,resize and check for any defects.

4.
Pistons,,,,,I want to use a good brand of pistons,,,not the most expensive,,this is not a racing engine,,,just a nice hot engine.
I don’t think I will use the 4 ring system,,,I believe 3 rings will be fine.
Being that the pistons will be a modern aluminum piston and will be machined with a barrel shape to fit better in the bore ,and not prone to a lot of skirt movement.

5.
The camshaft will probably be a nice Isky grind,,,not sure yet.
I have looked at some,,somewhere in the .365 range maybe,,,not sure ,,,still early.
I would like to use the adjustable lifters if I can,,,,is that a good idea,,,I have just began to read about them.

6.
Valves,,,,,I would like to use a good stainless valve to be safe.
I would like to go bigger than stock,,,if I can?
I am considering going with a1.625 intake if I can make it fit?
The exhaust would probably be a 1.57,,,,I am still in the thinking stage with this.
I know most engines always used a slightly larger intake being that the mass of the fuel and the air is not as great after the combustion cycle,,,,no fuel droplets in the exhaust.

7.
The heads,,,,, I am thinking about a nice aluminum head,,,with a better chamber shaped to increase compression. I believe that compression within reason is free horsepower.
The aluminum ones have added capacity for more cooling water flow and fins to increase the cooling ability,,,,especially after the shutdown,(act as a heat sink),,,to help remove heat from the deck surface?
Although it uses bolts right now,,I plan to upgrade to studs for strength .

8.
Intake,,,,still don’t have a good direction there yet,,,but I am just starting here.
I am thinking a dual carb or single 4 barrel,,,,,not a bunch of carbs,,,,too much to keep up with I think.

9.
Ignition,,,planning on adapting a SBC dual point distributor,,I like dual points and believe that it will work great. I have a nice Accel dual point,,and several others,,,just plan on the Accel at this point.

That is about as far as I have gotten so far,,,still thinking and studying my options.

I am still in the planning stage here,,,any ideas?

Tommy

Some 'bench racing' thoughts:
1. No need to relieve. You'll just lose compression and won't gain airflow unless you have a large engine at high RPM, and a radical cam (plus a super trick porting job). Air has mass, therefore has inertia and resists changing direction (which hinders flow). So air is flowing upward as it enters the cylinder, then through the transfer area and down into the cylinder. If we can change its direction gradually the flow will be greater. Forcing the air to make a sharp turn out of the port, through the relief, and another sharp turn into the cylinder will hinder flow. Since you lost compression to make the relief, and won't have much extra flow through the relief, you end up with a net loss at normal street engine speeds.
6. Larger valves. Will the ports flow good enough to take advantage of
the larger valves? Most of the reading I've done indicates the ports are the limiting factor in airflow, not the valves.
7. Aluminum heads. They look pretty, but they take heat out of the combustion chamber and put it into the cooling system so quickly that some efficiency and power are lost.
9. Since this is a street engine, make sure your Accel unit has vacuum advance for better fuel mileage.

[Desoto291Hemi]

40Deluxe,
On the relief,,that was what I was thinking,,,,it seems to me I would lose more compression than I would ever gain back with flow.
Unless it was a racing engine,,,but this is not my plan.
Seems to me,,,if you need the area to get more flow,,,,massage the head area between the valves and piston.

The Accel unit is not vacuum advance,,,,but I wasn’t quite planning on it being completely streetable. I wanted some really good performance, not really considering mileage at this time.
I would really like to have at least 9 to 1 compression,,,,wishing more for close to 10 to 1.
I am reading all I can about this before I make any big decisions.

Thank you for the information,,,,and please give me more if possible.
I won’t turn any good advice down .

Tommy

[JSeery]

When you get JWLs book this is all covered in detail with dyno data to back it up.

[Desoto291Hemi]

Hey guys,,,sorry about the delay here.
I tried to post some more pics here and could not get it to let me.
It is like trying to pull teeth,,,Lol.
Anyway,,,I have posted a lot of pics on the Hamb,,,you can visit there and view the thread.

My username is the same over there,,,and the title of the thread is the same as this one here.
I will try to get them posted here when possible.

Tommy

[JSeery]

It's most likely a size issue. The HAMB doesn't have the same size limit, on the Barn jpg files need to be less than around 540kb, most photo files are in the mb range. If you reduce the file size they will post.

[Ol' Ron]

You have allot of good ideas there, and most are doable. However, you must have a reason to make a modification. What gains will these changes make.Milling the head for .045 is a very good idea, because it improves low end throttle response and improves fuel mileage. But instarging the valves is only beneficial at hi RPms, and the cost is very high JWLs book is a good choice.

[Fordestes]

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There are tradeoffs with flow versus high compression, it's the nature of the design ,that's why I run blowers for flow and compression ,however the superchargers tend to have their own set of problems which need to be addressed in some cases . My dad always would hand me a bushel basket to carry in order to try and catch the rods as he would say ''when they fly out .' ' check out the books available it will save a lot of headaches later down the road .

[Desoto291Hemi]

I just tried again to upload some pics and it said that a security token was missing.
Oh well,,,,they are some really nice pics of a pretty nice engine.
It is the best looking 70 year old core that I have ever seen.
It is a 1949 Mercury Flathead,,,,no internal rust,,,not stuck at all.
I have got it torn down to the cam and lifters right now.
The bores look fantastic,,the crank looks fantastic,,,I couldn’t be happier to find it.
Maybe I will figure the problem out here soon.

Tommy

[tubman]

Tommy,

Emailing the pictures to myself works for me. There are more efficient ways to do it, but this is the simplest to explain.

Denny

[JSeery]

Originally Posted by Desoto291Hemi

I just tried again to upload some pics and it said that a security token was missing.
Oh well,,,,they are some really nice pics of a pretty nice engine.
It is the best looking 70 year old core that I have ever seen.
It is a 1949 Mercury Flathead,,,,no internal rust,,,not stuck at all.
I have got it torn down to the cam and lifters right now.
The bores look fantastic,,the crank looks fantastic,,,I couldn’t be happier to find it.
Maybe I will figure the problem out here soon.

Tommy

If you email the photos to me I will post them for you: [email protected]