The elusive 224/3.7 MerCruiser banger

This thread has a LOT of information. Thanks to everyone who contributed!
I'm all in. Picking up a motor this weekend if the weather cooperates.

 

BUMP!!!

 

I am trying to understand the correct flexplate to use. Previous posts said to use the nonweighted flexplate. While shopping I found a choice of 28 or 50 oz counterweighted flexplates for 6 cyl and 302 motors. Is there another that has no counterweight?

 

Ford 250 six cylinder is zero balance with sbf crank pattern. Smaller sixes have different pattern. Larger sixes use larger wheel. All I can offer as I went custom flywheel stick shift

 

X2 : NO counterweights!!! Any more info about your application/planned build? If you go to the start of the original 'thread' you'll find answers to most of your questions. I know that it's a long read, but the info is there & valuable, especially if you're just getting started with this engine, as this engine does have some 'quirks' to it!(as does every other engine out there ; we're just used to them! LOL)

 

The 300 I6 is also zero balance and you can buy aftermarket zero balance flywheels.

 

300 is 164tooth, not 157

 

It is also possible to search the thread using keywords, figured this out after reading it all, but it's good for finding what I remember reading somewhere in the thread. I believe there is a reference to a zero balance flexplate in the thread.

 

Thanks tscheerer: I'm not 'puter-savvy enough for your short-cut, but I understand what you meant! I did find that by "reading' the whole thread that I was able to get more of a "feeling"(for want of a better word) for this engine(& some of it's peculiarities!! LOL!!) as I read on! Not that I'd ever claim expertise, as I've only built one engine so far & haven't actually "fired-it" yet. But the 'build' progresses, & I'm looking forward to that day! I feel that I gain knowledge from every comment or critique that's been entered here, so thank all of you for taking the time to relate your own experiences with this engine!!!

 

Somewhere in this thread I saw that it was specified to use the flexplate from an 84 5.0 Mustang. I made a mental note of it at the time, but please double check, as believe it or not I have been wrong a time or two before lol.

 

Unless that 5.0 Mustang was an 'internal balance' motor, the flexplate will still be weighted to balance the motor. It will still bolt-up to the MerCruiser, but the weight makes it not useable for us. If the flexplate was an aftermarket unit specifically for an 'internal balance' motor, then we could use it safely.

 

Please go back and read the posts more carefully because the information I posted was only for putting a manual transmission onto a mercruiser motor. This is a summary of it:

A standard small block chevy bell housing will bolt on but it will not fit over the flywheel.. For things to fit requires:
1. milling 5/8" off of the back end of the block for a manual transmission setup (it takes a great big mill to do this) an aerospace outfit milled mine.
2. use the mercruiser flywheel it is a zero balance ford flywheel
3. a mustang clutch pressure plate (84 mustang) bolted onto my mercruiser flywheel
4 use a chevrolet clutch disk with splines to fit your chevrolet manual transmission

You are thinking of an automatic. The manual transmission instructions do not work for that. I know the input shaft length is different. We posted that information also.
It is my memory that that the input shaft for the automatic is so much longer than that for the manual tranny that instead of milling the block, you will make a spacer. I've little other information except to suggest a smaller diameter starter as I don't do automatics (they are ruled out in the cars that I run).

 

Perhaps you can grind or mill the weight off.

Drill the back end of your adapter fit a Ford transmission.
use dowel pins to keep it exactly where it needs to be. As you are going to do this step anyway, less work is involved than adapting to a chevy tranny. But what you do all depends on the length of the input shaft.

 

Just remembered you need flexplate with Chevy convertor pattern for Chevy auto. I posted one long time ago so just have to read back.

 

Phil1934, That is the information I was looking for. I also remembered the '84 302 information that was previously posted. I believe that is a 28 oz weighted part. The 250 six flexplate is what I will search for.
The local converter shop will put the Ford bolt pattern on the front of a Chevy converter for me.
I am not 100% sure I will be using an automatic yet. If I do it will be a Powerglide.
My project is for off road use. It will be locked into low gear. Low on a Powerglide isn't really low enough for me, but I don't want the added power loss of a 350 Turbo. I don't know if the S-10 5 speed is stong enough for my useage. I need to keep it light so an aluminum housing is needed.

 

There are several of these being built now. I have talked with 3 others currently building them.
2 of the guys are planning on using reproduction Boss 429 heads.
The other is going into a small street strip car. I believe that one has a Trick Flow head, dry sump oiling, EFI, cam cut from a new custom core, and a custom new crank with a Chevy bolt pattern. I want to see this one when it is done!
There is another local to me running in a '32 Ford roadster. It has dual Webbers on it.

My motor will probably turn into a longer term project. I would like to say it will be done this summer, but more likely next spring. I have not picked it up yet. I actually have 2 to pick up. One is a 170 hp the other is a 185hp. The 170 had a knock. The 185 was reportedly running well 2 years ago, but hasn't been started since. I am expecting at a .030 overbore. I plan to offset grind the crank for a stroker. Current plans are to use BBC rods, but I would appreciate any input on other stroker options! A turbocharger is likely. I have thought about one of the GM and Ford supercharger setups for modification. Again any suggestions would be appreciated!

 

It appears this flexplate will solve the Ford crank bolt pattern to GM torque converter issues.
https://www.prw-usa.com/product/-platinum-series-sfi-rated-steel-flexplate
It is currently $89 on Amazon with free shipping.
The part description says "Ford 289-351W, 1962-82, 157 Tooth, Small Block, Eagle or Scat Crank, Internal Balance", and "Note: Small & Big Block Ford applications feature both Ford and GM converter patterns"
This is the correct crank bolt pattern isn't it?

 

Yes. I borrowed a 289 flywheel when I made mine.

 

I drilled the stock flywheel for the Chevy torque converter and made a pilot bushing to hold the nose of the TQ in the center of the flywheel. This also allowed me to not need to mill anything off the engine block or bell housing. Everything bolts up nicely. TH350 trans bolts right up.

 

It has been nearly 2 months since I said I was bringing my motor home. I finally got it this week. Disassembly has begun. I usually clean and detail as I disassemble.
Originally I was going to cut 5/8 from the bellhousing. It doesn't look like there would be to much thread depth left for those bolts. Anyone have any thoughts on this?
Would it work to put 5/8 spacers between the flexplate (see 3 posts above) and torque converter? I could add a spacer on the flexplate to align the nose of the torque converter also? Would that eliminate any machining of the crank?
I have a 350 turbo trans and converter here but have not slid the 2 together.
Above Bad Zuk said he put the torque converter on the original flywheel. I want to eliminate the flywheel to save some weight. The flex plate would be a lot lighter.

 

I wonder if the heavy flywheel wouldn't be better to smooth out the pulsing of the banger.

 

Here is an off topic one that I will be wiring soon. Fuel injected, turbo, one off crankshaft, dry sump, intercooled with CO2,... and hooked to a powerglide. Competition cams is making the one off camshaft now. Should be streetable but fast on the strip. Lots of one of a kind aluminum and stainless work. It belongs to a good friend of mine Doug Lee. http://propan.net/

 

More pics of that one please!

 

The pictures I have are older ones. I will take a few new photos the next time I am at his shop and then I will post them. All the intake and exhaust are one of a kind and all of it is a work of art.

John

 

WZ Junk's photo is of the motor I was talking about in post 1188 above.
Doug does super work.

 

The flywheel would smooth out some vibration. I am fighting a weight limit, so planning to eliminate the flywheel.

 

Doug made his own flexplate and added the starter band. I sandblasted it for him a couple of weeks ago. I never thought of making your own flexplate until I saw Doug's. The outside diameter is critical.

John

 

Beck;

If you are still in search of a internal balance flex plate, I picked up a new one at Summit scratch and dent sale this am.

Craig

 

I realize this is a 5 yr old post. My question still remians.
From this post I understand that the oil pump needs to be centered with the bolt holes? Short machined sleeves inserted into the pump holes would center it. I do not have the Mercruiser tool to install the pump and was wondering if this would work?

 

Craig, I purchased one on Amazon this week. It should arrive today. Darn, I sould have waited another week.