428 Super Cobra Jet rebuild-help!

[SFM5S159]

Guys,
I recently had a stroke of good luck and became the proud owner of an unmolested 428 SCJ that I am going to install in my '67 GT500. The engine is STD bore and seems never to have been apart, the pistons and all bearings are all STD original Ford parts.
Here is where I need a little help with the SCJ vs the std 428 or CJ:
What flywheel can I use with my SCJ? I have read that they are different in some manner. I do not have the flywheel that was on the motor.
Also, I noticed that the balancer/pulley setup is different on the SCJ vs my 428 PI motor in the Shelby. Should I anticipate a problem with belt alignment by going to the SCJ motor?
I am aware of the different balancer and "hatchet" counterwieght on the SCJ, but I do not know what this means in terms of engine balance.
Any help and info would be welcome
Thanks
Mike.

[xlr8or]

The 428 crankshaft is externally balanced so you need the damper, the "hatchet" and the flywheel on when balancing the rotating assembly.
Your engine builder should be able to provide you with the appropriate parts.

[Sizzler]

First question I'd have is: do you plan on taking this engine apart and rebuilding it or do you just want to add the flywheel, install and go?

You say the pulley arrangement is different but apparently the pulley's are all there. So what's the problem? Do you mean the water pump pulley and/or alternator pulley might be offset? Did the motor come with the alternator and water pump, alternator and water pump pullies?

Need more info...

[Woodz428]

I'm in for lunch and it seems that all the books one FEs are in the shop currently, I just finished up a '70 428 SCJ, but I am pretty certain that the flywheel weight is the same for all the 428/410 engines. The part # is specific, but the weight is the same. the hatchet at the front is supposed to compensate for the extra weight of the rods. If I find our differently when I go back out,I'll repost later. But my recollection is that other than the part# it is weighted the same. I did one last year that was running a regular flywheel and we changed it, because he wanted the correct #'s one for his rare '69 Mustang GT with a SCJ. It was never a problem.

[Jon Miller]

I've got a 428SCJ that came with a C6 automatic. I changed to a top loader and went with an aluminum flywheel which I had match balanced to the flex plate I took off. The flywheel was nothing special, just a "standard" FE part. It cost me $200 to balance, and they did have to add some weights, but it worked just fine.




I can rent you the 10 year old for the install if you like, he's got SCJ experience!

Jon

[SFM5S159]

Sounds like my std 428 flywheel will work.
As far as the pullies, my 428 PI motor has the pulley over the top of the balancer and the SCJ has that extra large balancer sticking out and the pulley on the front of it. It seems further away from the face of the block ti the edge of the belt. I'll just have to measure and figure it out.
Thanks guys.
Mike

[Woodz428]

I think you'll find the pulley groove at the same points. The balancer goes back toward the engine to compensate.

[Mr427]

The FOUR flywheels:
Guys; the 428 has AT LEAST four different balance specs for its flywheels, possibly as many as six. Why?

First, you had the 1966-68 Q-code Thunderbird / Marauder / 7- litre XL engines. That package came with a C-6, and it MIGHT have the same balance specs as the std. Cobra Jet engine.

Then there was the CJ, both manual and automatic. Each had its different flywheels and probably different piston weights (682 grams)

The SCJ has yet another balance specification, since it has the "LeMans", capscrew connecting rods and heavier pistons at 712 grams.

There is a third wieght figure, but I can not state what it was or which model it was. I think it was a version of the CJ engine, w. piston weights between 690 and 700 grams.

So, ANY mix and match of flywheels on these engines may result in failed rear main bearings and in the end ruined cranks and blocks. I have seen it happen, more than once. One particular case involved a ´67 Gt-500, that was converted from auto to manual. The part number on the flywheel was correct, still the engine would not not balance out correctly. At between 2200 and 4500 rpms it would vibrate and you could feel it up through the floors and finally the engine failed.

This is my main cause for my allergic reactions to externally balanced engines.

Have it balanced if you install a new flywheel. You will be glad you did!

[FFR428]

The SCJ did use a thicker and larger balancer. They are the same as ther earlier C4 427 balancer. The IUA SCJ crank has the front hatchet added for balance as mentioned. The main differnece between the IUA SCJ and the more common IUB CJ is the weight pad ontop of the 7th counterweight of the IUB is missing from the IUA. With the use of the LeMans rods the IUA was balanced with more weight on the nose hence the hatchet crank spacer added. Why Ford chose to put more weight on the nose is beyond me. A recent disscussion on the net54 forum revealed that the SCJ and CJ flywheels are basically the same item. Just the SCJ uses a different part number forthe CJ and I'm sure the balance is slightly different besides. A forum member spent years tracking down a mint SCJ flywheel and paid $$$$$ for it only to discover it's a match except final balance to the CJ's. The SCJ had a C9ZE part number and the CJ a C8OE.

G.

[SFM5S159]

Hmmm.....so do I use my 428 PI flywheel and of course have the whole thing balanced?
I have read a lot of different ideas on this subject....
Thanks,
MC

[Mr427]

YES!
IF you have the engine apart, have it dynamically balanced with the "new" flywheel and front crank spacer / counterweight and harmonic balancer. The crank spacer and as-cast-counterweight, really are the critical part of this setup. The harmonic balancer is less important, although you need a heavier one for higher RPM operations. All that does is really cancel out mechanical vibrations that stem from various rotational misbehaivor inside the engine, stemming from issues like spark plug condition, timing, fuel stability and other issues that ifluence how the engine behaves under various conditions.

[olddog]

Jim Dove on his web site highly recomends adding mallory (sp?) metal to the 428 crank, which allows it to be internally ballanced. Then you can use any non-428 FE flywheel. I personally never liked externally ballance engines, so it sounds like sound advice to me.

http://www.doveengineparts.com/

click "Jim's tool box"
then click "insites into the Ford FE"
then scroll down to item #4.

Most everything in Jim's tool box is interesting to read.

[Mr427]

Hi it´s me again!
Jim Dove is right on the money. I have no particular expertise on the very narrow subject of external versus internal balancing; benefits or demerits of either one.

However, I can state from experience that the external stuff can cause a lot of problems and burned dollar bills if you don´t know what you are doing. Once you have your engine together, WITH the external stuff and you KNOW it was checked by a reputable machine shop and given the go ahead.

Then you will know that you can stand on it at 6000rpm+ without concern. But as for us novices and amateurs, zero is the way to go.

[SFM5S159]

That seems like the best advice I have received so far!
There is a bunch of good stuff as far as FE tips on his site.
Thanks!

[Tout]

You can gain a wealth of information from the members of the cobra jet registry, this site is dedicated to all CJ and SCJ cars.Help , parts, and correct restoration tips.
Tout