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Projects Re-engine-ering my 25 model-T coupe

Discussion in 'Traditional Hot Rods' started by Retired, Oct 2, 2024.

  1. Budget36
    Joined: Nov 29, 2014
    Posts: 14,422

    Budget36
    Member

    No worries. Im a product of listening to too much Cheech and Chong growing up. Many times its the “Evelyn Woodhead speed reading course” ;)
     
    sidevalve8ba and Retired like this.
  2. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    Thank you for this. ..
    Would you mind figuring out what the compression would be on a stock, 239 cubic engine with 51 CC heads ?
     
  3. 6sally6
    Joined: Feb 16, 2014
    Posts: 2,643

    6sally6
    Member

    Looks like you 'got-it-go'in-on!'...I never worked on the inside of a flattie before. Although they are different from an OHV there are many commonalities between them.
    (You didn't ask but..) I would have tried a few things on the first engine before.............
    Like trying a tank full of E-85 (more octane and cheaper than regular fuel.)as stated above.
    Like doing a little hand porting around the valves removing some material and helping breathing
    Like a thicker head gasket(Cometic) or doubling up two stock gaskets
    Like running a cooler thermostat/increased cooling
    Like insulating the fuel lines to have cooler fuel.
    No matter now........I'm enjoying your flattie build.
    6sally6
     
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  4. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    If I had not already had the other stock engine sitting in my garage, I would have been willing to try some of the suggestions that have been made.
    With switching the engines, I'll be able to correct the sparknock problem and still have the high performance short block to sell to raise some money to work on other projects with.

    The E85 gas has been mentioned before so I went searching for it in our area and couldn't find a station that list selling it ?
     
  5. 29Sleeper
    Joined: Oct 25, 2023
    Posts: 268

    29Sleeper
    Member
    from SoCal

    Compression ratio is too high - end of discussion.
    Now what do you do about it?
    Better gas - easiest - Yes E85 is cheap but you'll need to eliminate anything it can eat in the fuel system. Ethanol is 100+ octane but it's not as efficient as gas. You'll need to rejet to get it to work in your car.
    2 head gaskets - not reliable
    New heads - permanent fix
    Machine a little off the tops of the pistons - depends on what's in there now.
     
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  6. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    With the external parts removed from the first engine, I've started fitting them to the second engine. ...
    This is my homemade transmission adapter and it attaches to the flathead with four countersunk 3/8 allen head screws.
    The two holes at the bottom of the adapter will each have a bolt going in from the otherside of the engine block and go thru the adapter plate and be screwed into threaded bosses that are welded onto the lower corners of the transmission housing.

    DSCN2315.JPG



    I had to make a 1 inch thick spacer to fit onto the Ford crank flange with the Chevy flexplate fitting onto it.
    This is the transmission side.

    DSCN2317.JPG


    And this is the crank side.

    DSCN2318.JPG



    The crank is strapped onto the die cart to hold it steady.

    DSCN2321.JPG



    The flexplate is fastened onto the crank with four 7/16 bolts so I can drill and tap the other two bolt holes in the crank flange.

    DSCN2323.JPG



    This assembly is now fastened in place with eight bolts. The six gold colored bolts go all the way thru the spacer and are threaded into the crank flange.

    DSCN2326.JPG




    With the crank resting in the block, I drilled and tapped two holes in the bottom of the block.
    The mounting bracket that I made for using a newer small GM starter is bolted to the mounting bracket with allen screws.

    DSCN2326-1.JPG



    The starter then is fastened to the mounting bracket.

    DSCN2327.JPG



    This takes two shims for a total thickness of .070 for the gears to engage properly.

    DSCN2328.JPG
     
  7. chicken
    Joined: Aug 15, 2004
    Posts: 593

    chicken
    Member
    from Kansas

    Really close to 9:1, a bit less if the piston edges don't quite come up even with the tops of the bores. Borderline for pump gas, but with a bit of milling in the areas above the valves and making sure the piston to cylinder head distance at tdc is approx .040" it'd be a great running engine.

    Oh, and Ray....that's some seriously nice work and modification that you've done. I've been there and it's a lot of studying and figuring!
     
    Last edited: Oct 4, 2024
    Retired likes this.
  8. seb fontana
    Joined: Sep 1, 2005
    Posts: 8,830

    seb fontana
    Member
    from ct

    I guess the trans is a GM, I don't think you mentioned what it is? You did alot of good work adapting the trans to the FH. Nice.
     
    hotrodjack33 and Retired like this.
  9. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    Thank you.
     
  10. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    You're right, I don't think I mentioned that. It's a Chevy 350 automatic.
     
  11. dwollam
    Joined: Oct 22, 2012
    Posts: 2,506

    dwollam
    Member

    I run double head gaskets on my 286 flatty. Been on there for about 20 years with no problems.

    In your case, I would of bought new or good used head and been done with it. I fear you will still be to high compression on the new engine.

    Dave
     
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  12. tubman
    Joined: May 16, 2007
    Posts: 7,347

    tubman
    ALLIANCE MEMBER

    Maybe I missed it (or you just didn't mention it), but I see no reference to crack-checking the new block. Putting any amount of effort into an 80 year old engine without doing so is taking a big gamble.

    I agree that approaching this by using different heads (or reworking the existing set) would be the best path. (You all know about me and proper quench dimensions.)
     
    Retired likes this.
  13. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    1 - I'm a little confused about the reasoning on some of the responses that have been posted here.
    It seams like most of you think I should keep the 1st block instead of going with the 2ed block and either buy new heads or do a lot of machining to reduce the compression.

    First off, I don't have $900 to spend on new heads and if I did, I wouldn't buy them anyway.
    I like my Navarro heads. You don't see them that often. The new heads that are $850 plus tax and shipping, are Offenhauser which are very common.

    2 - Thanks to Chiken from Kansas, I know that the 1st engine has 9.75-1 compression. The 2ed engine has a little under 9.1-1 with using my Navarro heads.
    Simply by using the 2ed engine, I've already dropped .65-1 compression, That seams like a no brainer to me.

    3 - It has been mentioned here and on other post that I have read, that there is no problem with using 2 head gaskets.
    I have a pair of the old Victor metal clad gaskets with 3.250 bore hanging on my garage wall and I can get another pair for less than $60.
    Together, they measure .160 thick and I wouldn't think that they would compress down more than .01 or .02 so that will open up the compression chamber and maybe even drop the compression down to around 8-1 ?

    As you can tell from the color left on the heads of the 1st engine, I always use a copper seal gasket spray on head gaskets and I've never had any problem with them leaking.

    DSCN2332.JPG


    4 - There seams to be a lot of concern with cracks in the blocks. It's hard to find a flathead now days that doesn't have at least one crack between the water hole and the thread in the center of the block between the first two bores or the last two bores.
    So what ! I have always used a non hardening gasket sealer like Permatex High Tack on all the head bolt threads simply because they are threaded into the water jacket and they can leak around the threads themselves.

    I did that with the my first flathead way back in 1963 and with every one that I've had since. I know at least two of the engines that I've had over the years had cracks in those places because they were clearly visible.

    I was lucky with the race engine that I just took out of this car in that it doesn't have any cracks because up till now, it hasn't been run since the 1970's at the latest.
    This replacement block has a crack in each of those four spots, I knew that when I bought the thing. From past experience, I know they won't cause me any problems !
     
    INVISIBLEKID and flatheadpete like this.
  14. hrm2k
    Joined: Oct 2, 2007
    Posts: 5,150

    hrm2k
    ALLIANCE MEMBER

    Are you going to keep the Jag rear visible in the first picture ?
     
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  15. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    That is a 65 Mustang rear axle with a quick change rear cover adapted to it.
    A02780.jpg
     
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  16. hrm2k
    Joined: Oct 2, 2007
    Posts: 5,150

    hrm2k
    ALLIANCE MEMBER

    sorry, my mistake ….sure looked independent in that picture
     
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  17. tubman
    Joined: May 16, 2007
    Posts: 7,347

    tubman
    ALLIANCE MEMBER

    How about running a set of stock heads for a while? The're cheap enough and should give you a good indication about what's going on. The only problem here is the cost of head gaskets these days. Around $60 a pair for regular gaskets, but you can spend up to $200 for Cometics. I only use grease when installing head gaskets. With properly prepared mounting surfaces, leaks are not a problem and they come right off. Copper spray and other sealants make the gaskets difficult to remove and they are frequently not able to be reused. When you are on a budget, being able to reuse a set of head gaskets 2 or 3 times is a real moneysaver. Save the sealant for the headbolt/stud threads.

    About cracks. The obvious cracks that a lot of engines have between the water passage and bolt hole are harmless and common enough to be called "part number cracks". (Meaning they are so common that some say they have their own Ford part number.) Other not so obvious cracks can render an otherwise pristine block useless. It all depends on whether you feel lucky. There are dozens of threads on the forums about guys who have gone through as many as 7 blocks before they found a usable one. I, personally, have been lucky in that 6 of the seven flathead blocks I have gotten over the years have been good. I even had 4 without the "part number cracks".

    Let's hope you get lucky.
     
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  18. chicken
    Joined: Aug 15, 2004
    Posts: 593

    chicken
    Member
    from Kansas

    Quote:

    "3 - It has been mentioned here and on other post that I have read, that there is no problem with using 2 head gaskets.
    I have a pair of the old Victor metal clad gaskets with 3.250 bore hanging on my garage wall and I can get another pair for less than $60.
    Together, they measure .160 thick and I wouldn't think that they would compress down more than .01 or .02 so that will open up the compression chamber and maybe even drop the compression down to around 8-1 ?"

    You are almost right on the money...a close guess will be that the extra gasket will add about 10cc or a bit more and put you at 7.9 or so. (close guess) What you will NOT have is a good quench distance from piston crown to combustion surface of the heads (it'll basically become an open chamber), but as with anything it's all a balancing act and you work with what you have. If you like the heads and are willing to experiment a bit ( as I know you are) why not try it? Some great things can happen when a person stops listening to accepted practices. I do wonder if the more open chamber might want a bit more timing than "normal".
     
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  19. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    Thanks. I'll keep that in mind about the timing. I played around a lot with setting the timing and changing the limit springs in the distributor trying to stop the spark knock.
     
  20. Budget36
    Joined: Nov 29, 2014
    Posts: 14,422

    Budget36
    Member

    I’m not sure about a modified FH and my only experience has been with the “diver helmet” setups. Just line the mark up and go.
    But Jim Linder (RIP) did many FH and other conversations for distributors.
    But he saw no more power past some low total timing, like 16/18 BTDC at high rpms.
    Obviously though, you mention retarding the timing helped the pinging, and a loss of power.
    But I just thought I’d bring it up.
     
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  21. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    This is an electronic distributor made specifically for the 49-53 flathead.
    The directions show initial timing set at 5 degrees advance and a total advance timing of no more than 20 degrees so that would fit in with that 16/18 figure.
     
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  22. tubman
    Joined: May 16, 2007
    Posts: 7,347

    tubman
    ALLIANCE MEMBER

    That sounds about right; a little low if anything. This is assuming that the advance system is working properly. It would be nice if it could be checked on a distributor machine or even with an advance timing light. Some of the later electronic distributors for flatheads came with SBC advance curves, which are too much.
     
    Last edited: Oct 5, 2024
    sidevalve8ba, Budget36 and Retired like this.
  23. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    My son has an advance timing light that he uses to tune his 68 Firebird for racing.
    It doesn't work on my flathead because I have solid wire core plug wires and they throw the light off.
    It took him awhile to figure out what the heck was going on when he first tried to set up my timing.
     
  24. Budget36
    Joined: Nov 29, 2014
    Posts: 14,422

    Budget36
    Member

    How about a “bypass” regular spark plug wire from cap to plug, would that allow his light to work properly?
     
    Retired and chicken like this.
  25. tubman
    Joined: May 16, 2007
    Posts: 7,347

    tubman
    ALLIANCE MEMBER

    You only need to check one lead. Why not replace the coil wire with a suppression wire? Actually, I have found that using suppression wire there (and there only) doesn't seem to hurt anything and also cleans up the sound system interference.
     
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  26. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    Thank you. We didn't know that.
     
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  27. Retired
    Joined: Jan 4, 2009
    Posts: 366

    Retired
    Member

    Thank you. That is a good idea. I don't have a radio in the car but I have noticed that I can sometimes mess up someone else's radio when I pull up beside them.
    Actually, I sort of like doing that to these guys that you can feel the vibration of there sound from 50 foot away.
     
  28. 51504bat
    Joined: May 22, 2010
    Posts: 5,153

    51504bat
    ALLIANCE MEMBER

    $3.99 for 87 today at an Arco Station by the freeway. Further up town a Sinclair station was $3.89 cash price.
     
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  29. tubman
    Joined: May 16, 2007
    Posts: 7,347

    tubman
    ALLIANCE MEMBER

    $2.89 in the Minnesota tourist region where they constantly try to price-gouge the tourists.
     
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  30. Budget36
    Joined: Nov 29, 2014
    Posts: 14,422

    Budget36
    Member

    Well of course gas is less expensive, you folk are further from refineries! :)
     
    51504bat likes this.

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