Technical Flathead Cam Question

I have a late 8BA that was rebuilt and then seemingly run very little. Makes sense since I pulled it from a piece of machinery. No apparent rust, cylinder walls look good, only one “ford part number” crack that I have found. It’s been bored 0.825 over and the crank turned.
My question: How damn stupid would I be to replace the cam with a 400 Jr and run it?
Feel free to bash, I’m here to learn
The engine:

 

I was wondering the same thing about one of my 8BA’s sitting here not doing anything. Very low mileage rebuild (less than 10,000 miles) that was done 35 years ago. I’m watching this thread for sure

 

As the youth would say “send it”

 

Pretty nice clean engine but the picture doesn't seem to show the crack. At least I can't find it. I would be more concerned about the number 8 piston and cylinder. It looks loose enough to turn sideways. It could be just the angle of the picture but I would check it. Cracks, if not too bad can be fixed several different ways. Pinning is the best, in my opinion. A competent machine shop could do that. I would do some more investigation before I invested much money. If you use a new cam you will also need new liters. Used lifters on a new cam is a big no no.

 

What are you planning on putting it in?

It makes a difference in cam choice.

 

Thanks Glenn, I agree on the lifters for sure, but was thinking maybe I could avoid a full tear down. The cylinders piston fit seems fine, I have oil in the cylinders and so that may reflect in the photos. The crack is between cylinders 7 and 8:

 

Yup, factory crack right there!

 

Common crack. Both the crack, bolt and the water passage go into the water, so this crack is not a problem. Be sure to use a sealant on all the bolt threads. All but a couple of them go into the water jacket. Teflon pipe dope or plain old plumbers pipe dope work just fine. Just don't over tighten the head bolts. Do not use Teflon tape. Put a dab of gasket goo over the crack before installing the gasket. You'll be good to go.

 

I once had a block so good it didn't even have one of those cracks.

 

Hope you mean .080 over bore not .800. That’s like 7/8 of an inch.

 

Fat fingers, small phone

 

No plans. Run stand, then maybe the coupe, or the belly tank if I ever get to it. Honestly, I like the sound of the 400 jr, and they seem to be a very popular choice.

 

I have a 400jr in my 8ba with a manual 4 speed. It sounds great and pulls well at speed. But for just driving around in the suburbs at say 40 mph it is a bit lumpy and you need to change down a lot. It's in a 32 pickup so vehicle is light. If I had my time again I would go with a slightly less aggressive cam.

 

Max 1 would be a bunch better for a driver. If it's just to listen to on the run stand in the shop, then the 400JR is great!

 

Too much cam for too little an engine

 

Agree with Bearing Burner

 

Building an engine just to hear it run on a stand is kind of a waste (hard on the rings, too).

Tell ya what; I'll trade you an hour recording of my flathead with a 400JR for your engine. Hell, I'll even throw in a recording of my early hemi with an Engle roller tappet as well!

 

Tempting, very generous offer. I think I’ll off for the moment.
I wasn’t aware the using a run stand is hard on the rings… why is that?

 

Rings rely on gas pressure from combustion to seal well and to seat properly. No-load running doesn't create enough pressure behind the ring to force it out against the cylinder wall properly.

 

What he said.

 

Very good to know, thanks. I’ve used mine often to bring the engine up to temp etc. mostly to be sure thermostats open and things are sealed. Also for tuning. I guess I should limit the time I spend doing that.

 

On a newly built engine it's best to keep unloaded running to a minimum. Once it has some miles on it, no problem.

 

My suggestion would be an L100 cam. Best street cam I have used, but you might have to do some work on the shrouds in the heads.

 

X2 ...... these cams are the hot ticket for street use, I bought one but have not built the engine as yet.

 

I love the sound of the 400 jr... The Max 1 just sounds like limp wristed cam. I have done some research and the Isky 1007b is the best find I have found for an good sound and good pull.

Isky 1007b grind. The sound is aggressive, not as much lift so the low end power band is improved. There are alot of videos on it, great sounding cam.....

 

Yep. I got the Isky 1007B grind from Pete. Still waiting to get mine started though…

 

Thanks for all the input and suggestions, super helpful. I’ll need to learn how to select the best cam for my near stock flattie. @stubbsrodandcustom that 1007b does sound very good!
Knowing now that the 400jr is probably too aggressive for my application, this is one of the videos that really turned me on to it (maybe belongs to someone here):

 

And this:

 

L100

https://www.instagram.com/p/BmMs1GrHEogzpbc0-KLUYb8VN3n9OLwMOnWgzo0/?igsh=MWV0Z2F4emM0b2NtbQ==

https://www.instagram.com/reel/CtDB4lXg7qc/?igsh=bzliaDk5c3U5dmR5