8Ba cam selection

3twinridges

3twinridges

Well-known member
I took all my parts down to the machine shop today to get the 8BA build going. I thought I had two nos cams, a 1CM and an EAB but upon opening the boxes both were void of cosmoline and had signs of wear. The machine shop didn’t like either of them.

This will be 4” build, probably 40 or 60 over, stock carb and ignition running an F1. Heads are EAB with stock rotators.

What’s a good new off the shelf cam for a build/use like that?

JB
 
I think your first two choices were the best. Especially where you want to keep the stock carb and ignition. Maybe you can get one of those reground to the 1CM or EAB specs…….Mark
 
I know! I just called Delta and they can grind an 8cm out of my EAB core. I may go that route but the turnaround time is going to probably really aggravate the machine shop!

JB
 
Last year I came across these after I had already bought an nos 8rt Canadian surplus truck cam. Carpenters says they are nos and while I don't see it today, I think I read they are surplus Canadian 7RT cams . Seems I read they had bought something like 250 of them. For what it's worth, I coud not be happier with my 8RT. All kinds of low end torque. Unfortunately I got 3rd gen's last one of those. Here's the 7rt and note 149.00
https://www.dennis-carpenter.com/trucks/engine/camshaft/7rt-6252-noscamshaft
 
Thanks GB! After thinking about it more I am going to bite the bullet and send the EAB core off and an 8CM grind done. Although it might not sound the best, it will still sound good and pull like a mule.

JB
 
3twinridges said:
I know! I just called Delta and they can grind an 8cm out of my EAB core. I may go that route but the turnaround time is going to probably really aggravate the machine shop!

JB
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Delta is super quick. Not sure where you live, but they use to offer same day service. If you are shipping it, you'll have it back within two weeks.

I am not a fan of stock cams. They do a lot well, but nothing really great.
May I suggest something different?

I know I may be an outlier, but if you are going through the trouble of rebuilding an engine and boring it out, adding compression with the EAB heads, why not hop it up a bit and make it even more fun to drive?

I would call Jerry @ Schneider Cams. They have a lot of grinds and he will match you up with one that will meet your needs.

I run a Potvin 3/8ths. Too much cam for what you are doing, but the Potvin cam is an incredible street cam in a light roadster. Schneider still grinds all of the Potvin grinds as well as their own.
 
I have an 8CM in the '51 Merc in my '51 coupe. I am happier with it than I was with the MAX1 in the 276 Merc in my old '36 3 window. Not so much for what the 8CM is, but for what the MAX1 wasn't.

EDIT : An interesting fact is that the curb weight of the '51 is 534 lbs. more than the '36.
 
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I am a big believer in not over-camming a motor. I have driven several cars with rebuilt engines using cams ranging from "improved stock" to "3/4 race" and none have driven as well or as strong in the rev ranges I drive as a good stock cam. I don't baby engines, and I don't rev the piss out of engines. I set idle somewhere in the 600 to 750 range and shift before 3,000 rpm. The strongest flathead I have driven is in a stock 1950 Mercury (heavy car) with a +0.060 bore (required to clean up the cylinders), an EAB cam (stock was damaged, EAB was available), stock heads milled a lot (.035 - .040 squish), and everything else stock. That car runs down the highway in overdrive at 80+ and gets there with authority.
 
Like Fred in post #9, I also wanted a smooth idle and good pulling power for a heavy vehicle. I built a very similar engine and have been thrilled with the outcome. Some of my friends here on the barn prefer an engine that's more on the hot rod side of things with a lopey idle and speed equipment, and I get that, but the engine described above is exactly what I'd personally hoped for.
 
38 coupe said:
I am a big believer in not over-camming a motor. I have driven several cars with rebuilt engines using cams ranging from "improved stock" to "3/4 race" and none have driven as well or as strong in the rev ranges I drive as a good stock cam. I don't baby engines, and I don't rev the piss out of engines. I set idle somewhere in the 600 to 750 range and shift before 3,000 rpm. The strongest flathead I have driven is in a stock 1950 Mercury (heavy car) with a +0.060 bore (required to clean up the cylinders), an EAB cam (stock was damaged, EAB was available), stock heads milled a lot (.035 - .040 squish), and everything else stock. That car runs down the highway in overdrive at 80+ and gets there with authority.
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Fred,

I fully respect your opinion, but I simply can't relate to it. As mentioned previously, I have a big motor at 292 c.i., but I've driven many "stock" flatheads. None, and I mean none, even come close to my hot rod motor.

My motor is in a light '28 roadster will spin the tires until red line in 2nd gear. There has been no stock motor that I've ever driven that even comes close to that type of performance.

My car will lope idle at 750 rpms all day long. Sounds like a race car at full throttle and pulls until you are too scared and have to let off the gas. I've been at over 100 mph on a GPS speedo and it would have gone more, but I let off.

When I say full race, it's truly that. Ported to the max, exhaust opened to 1.75", big valves, aluminum flywheel, and many other "tricks".

To each his own, but a stock motor simple can't compare to one that is truly full race.

One downside is I only get about 12-15 mpg with this set up. I don't care and run 25% 100LL AV gas to 75% 93 ethanol free unleaded in it.
 
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Tim this is an F1 farm truck that will occasionally go into town to get pine straw. That said, I do like a little pep in my step and the fact that it will be new piece. Calling Schneider tomorrow to see what their feedback is.

JB
 
Choose a cam for the way you'll be driving 90% of the time. From your description of your carb and ignition and the fact that it's a pickup used for errands I'd be cautious. The extra cubic inches ( stroke and bore, with the resulting compression boost) will do a LOT, perhaps without the need for much more cam. If you're mostly driving under 3000 rpm the stock cam is a fine choice. Above that, and with porting,more carb and compression....sure, bring on the big cams!
 
cadillac512 said:
Choose a cam for the way you'll be driving 90% of the time. From your description of your carb and ignition and the fact that it's a pickup used for errands I'd be cautious. The extra cubic inches ( stroke and bore, with the resulting compression boost) will do a LOT, perhaps without the need for much more cam. If you're mostly driving under 3000 rpm the stock cam is a fine choice. Above that, and with porting,more carb and compression....sure, bring on the big cams!
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Fair points all. Cams are like pizzas. Everybody likes theirs a little different.

Let us know what Jerry says after you speak to him.
 
Jerry recommended the 248F with 350 lift. On order and on the way! Jerry said it was very similar to a 1CM grind, nothing crazy, almost a stock cam with no issues to carb or timing!

JB
 
Fair points all. Cams are like pizzas. Everybody likes theirs a little different.

I was sitting here trying to find a way to say that, but Tim, I like your analogy. And hold the spicy peppers and achovies on my cam, I like them on the mild side.
 
That is an excellent analogy……I like my pizza with light Marinara sauce…..so I’m a stock cam guy!!…….but I’m going to build one big Flathead before I croak….that'll be a loaded pizza…EVERYTHING!!……I want that thing flamin’ !!!!!
 
flatford8 said:
That is an excellent analogy……I like my pizza with light Marinara sauce…..so I’m a stock cam guy!!…….but I’m going to build one big Flathead before I croak….that'll be a loaded pizza…EVERYTHING!!……I want that thing flamin’ !!!!!
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Hahahaha. Go for it!
 
3twinridges said:
Jerry recommended the 248F with 350 lift. On order and on the way! Jerry said it was very similar to a 1CM grind, nothing crazy, almost a stock cam with no issues to carb or timing!

JB
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Excellent choice. It'll serve you well in that pickup.




And Tim A and Flatford....Oh yeah, build a monster! Nothing better for a HOT ROD! :D
 
I have the 248F, it’s a nice looking cam. While they were cutting it I found a NOS EAB cam. The 248F came with a degree card which intimidates me and makes me think I will have issues setting initial timing. I am used to setting timing with a stock cam using a timing light and the crank pulley and timing cover.

JB
 
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