433 Isky vs 400Jr vs Schneider 284F, .425" lift......

Fellow H.A.M.Bers.

I am currently in the planning stages of my upcoming '49-'53 Flathead build.

I have exchanged many emails with speed shops/H.A.M.Bers etc, and am leaning towards a 3 3/8 x 4 1/4 = 304ci or the 296ci Flathead N/A build.

Plan is:

• NAVARRO Heads.
• NAVARRO triple carb manifold with 94's or 97's. (Figured the size of the engine will be ok with 3 94's or 97's)
• Ross pistons.
• Need more info on ignitions for these type of builds.....
• Scat 4 1/4".

There the more solid plans for the moment.....

One thing that's really making me stop in my tracks is the CAM.

I really want this thing to "Rock-and-Roll" not only in power but sound etc...

I haven't forgotten either that Flatheads aren't a powerplant but I'm a flathead man!

So..... My options at the moment are: 433 Isky cam which I don't know terribly much about (bit more info would be great!)- 400Jr-Schneider 284F, .425" lift.......

I want a little bit more in depth user feedback on how these cams perform, what their differences are and what combo's you are running with these cams.

Will be driving this thing too so obviously I'll need a very good cooling system.

Also, it will be going in an 'A' Roadster. So it's gonna be a light car therefore, theoretically shouldn't be bad with the cam and crank and shouldn't be too hard getting it off the line....

Open to suggestions, experiences the lot.

Thanks.

HC.

 

Bump....

 

My only experience with the three listed is the 400 Jr. When I was but a youth, I crewed on a flathead-powered dragster. We started out with a 400 Jr. cam, which worked pretty well, but not as well as the Isky 404 we went to later. The motor was a 296, and as flatheads go, was pretty rowdy (as you might expect in a dragster). Hope you are planning on a T5 to take advantage of your motor; sounds like a very cool project.

 

Don't know about the T5?

Would maybe like something period ('39 3 speed) but when you go into builds like this you might need something to do it a bit more justice.........

Thanks for the input!

HC.

 

Really, for the street, I don't know that I'd go much more aggressive than the 400Jr, although, with your displacement, you can probably get away with it.

Isky 433 specs:
.410" lift, 280 adv duration, 263 .050" duration, 111* lob separation, .020" I/E clearance


The T5 isn't as popular a transmission swap down under as the Toyota Supra box is - either way, get some gearing.

 

My friend had a 49 Ford with a full house flathead 4 carbs, 9.5 heads isky 400 jr. cam and was winning red lite races against the 55 chevs back in 56.

 

Couple suggestions -- don't bore the thing to 3 3/8 . . . unless you happen to have an old race block that needs to go that far to run it. I'd bore to 3 5/16 -- that way you have at least another over-bore before the block is done (probably two). You'll need to do quite a bit of port/relief work to enable the large cubes and cam to work, so after you've invested 25 - 40 hours in the port work alone . . . would hate to see the block bored to it's last gasp. Also, before you ponder any of this, have the block de-rusted, magnafluxed and then sonic tested . . . to see what shape it is in, if it has core shift, etc..

Cams: There are a lot of big cams out there that sound cool, but are hard to run on the street (no low end). This is especially true with the old 3-speed trannys. I used to run a Potvin 425 Eliminator on the street - for about 2 years (drove it every day). It was a very good cam and one that would probably work well in that engine. I've never ran a 433 Isky, but I haven't heard too many folks very excited about it. The Isky 404-A (radius lifters) would be a hell of a cam in that engine, just more work to set it up, hard to find lifters, etc..

Best of luck, keep us posted!

 

I've run the 400jr and presently have a Potvin 415 in my 286 CI flatty. This is in a 3000# car and I'm more than pleased with the performance of either one. The suggestions above about going to a T-5 (which I did) is probably one of the best things you could do. You won't be sorry.

 

Hot cam + "period" wide-ratio 3-speed = complete slug, unless beaten with a stick.

 

There's a guy around here that had an engine with a 433 in it. Haven't seen it in years. Don't know the details on the engine, but it sounded awful nasty and not real streetable.

 

QUOTE=Bored&Stroked;4880596]Couple suggestions -- don't bore the thing to 3 3/8 . . . unless you happen to have an old race block that needs to go that far to run it. I'd bore to 3 5/16 -- that way you have at least another over-bore before the block is done (probably two). You'll need to do quite a bit of port/relief work to enable the large cubes and cam to work, so after you've invested 25 - 40 hours in the port work alone . . . would hate to see the block bored to it's last gasp. Also, before you ponder any of this, have the block de-rusted, magnafluxed and then sonic tested . . . to see what shape it is in, if it has core shift, etc..

Cams: There are a lot of big cams out there that sound cool, but are hard to run on the street (no low end). This is especially true with the old 3-speed trannys. I used to run a Potvin 425 Eliminator on the street - for about 2 years (drove it every day). It was a very good cam and one that would probably work well in that engine. I've never ran a 433 Isky, but I haven't heard too many folks very excited about it. The Isky 404-A (radius lifters) would be a hell of a cam in that engine, just more work to set it up, hard to find lifters, etc..

Best of luck, keep us posted![/QUOTE]

The hours don't particularly bother me as this is going to be a bit of a long term project but again, I know where your coming from in terms of building the thing then running it for a month!

There are NO two ways about getting the block de-rusted, magnafluxed and sonic tested.

The 404-A would be a crazy cam!!!

As you said and from what I've heard, you need special tools etc for the adding of that cam.

Could you please give me a bit more info on this cam?

Have you used it before?

Thanks for your input.

HC

 

I hear ya...........

HC.

 

Another question, with this type of build world you run forged pistons or just aluminum pistons???

HC.

 

Don't get hung up on hot cam names. Get one that works, I think enough guys here have suggested that and the same sound advise is given wherever 'bragging' is left out of the equation, including on the many other threads on this same subject here on the HAMB. It's been so since the beginning. When you have an engine that actually hauls, you can tell 'em whatever you like about the cam if it makes you feel good - a super hot cam sure won't!

 

Stick with the 400jr for the street . The others all require either mushroom lifters ,or radius lifters , all of which are a pain in the ass to get the correct machining done /special lifters and keyway slides ...AND these puppies wear real fast compared to a normal lifter .And if for any reason , and with a flathead , theres plenty of those ,just one of those little wire clips lets go ! How much did that build cost ya ?

 

Did you call Jerry at Schneider cams?
I'm sure he will suggest a 278F at the most for your engine.

I have a 304ci Scat engine kit here at home . The block(french) is at the machine shop
right know.It will have a wild cam (won' tell which one and a 5 speed

I also built a 284 ci engine for my '32 roadster (three speed) that "only" has a 270F
Schneider 0,395 cam.
I've used the 270F before and its a good cam.

I don`t like the 400jr cam......but that is personal preference....

I think a 4 1/4 stroke is a lot and you don`t want to rev it very high every day.

Michael

 

I also built a 284 ci engine for my '32 roadster (three speed) that "only" has a 270F
Schneider 0,395 cam.
I've used the 270F before and its a good cam.

I don`t like the 400jr cam......but that is personal preference....


Can you tell me more!

 

Please don't assume I'm questioning your knowledge or anything, but may I ask your reasoning behind this in terms of performance wise???

Thanks for your input.

HC.

 

I understand where your coming from and appreciate your input but the reason I am asking for first hand advice is that I have no experience with cams and builds.

Just a lot of reading, but in the end of the day, first hand, user advice tends to be very handy!

HC.

 

I don`t like the 400jr cause it has little duration compared to the lift.
I also think a bigger flathead need more than 258° (400jr).
That is why i prefer a 270° schneider over a 400jr.
Michael

 

No,
i will when the engine is running and i see how it performs
Michael

 

With you on that one.

Make sure you drop us a line and let us know how it goes.

Thanks.

HC.

 

I`m with Ernie on the size of the engine.304ci is too big for a street engine.
Walls get thin . 4 1/4 is a lot of stroke with ony 3 bearings down there
I won't use mine as a long distance driver.
Scat has a 284 ci (3 5/16 x 4 1/8) engine kit that is very good and affordable.
If you want more "sound" get a Potvin 3/8 cam.

I ask 10 people about Flathead cams will give you 100 options.....
Michael

 

I understand where your coming from but I want a big bad Flathead.

With the thin walls topic, that is my only concern as it does get hot here and I will be driving this thing.

I have been told that a good cooling system will do the job by a speedshop.

Is this true?

HC.

 

HotRodMickey has it about right as far as I'm concerned -- especially if you want to put a lot of miles on it, have an engine that lasts and one that can be rebuilt a couple times. I understand you wanting a big-bad flathead . . . have you ever ran a flathead before - above 270 cubes?

A 284 cube one is one heck of a good engine if you build it right and the Potvin 3/8 is a great cam . . . and sounds really good as well. Another option . . . build a 284 with a blower on it -- now that will make a bad-ass flathead!

Checkout some posts by 'RustyBucket' - you'll see his 3 5/16 x 4" stroke flathead with a Potvin 3/8 cam. It has a nice port job, street relief and sounds fantastic. We built the motor last summer and it really moves that Model A roadster down the road.

 

I second that.
Have you ever been in a 2000lbs car with a 270ci or more Flathead?
I had a 255CI Merc(cam heads. etc) in a little T Sedan with a 5speed and that scared the shit out the people that i took for a ride!

Michael

 

We are runnning the 433 Isky - it is a lot of cam! I would not call it street-able - running it with the '39 box is a handful. We are running larger Chevy valves - we ended up taking a lot of material out of the heads - by the time you count to 10 the heads are hot. We originally ran a radiator - but to be honest, did absolutely nothing. Tried to run it on methanol (would idle real cool, intake was frosty white), but would only idle - so much overlap on the cam that we could not get enough volume of air/methanol into it. Plan someday is to put it back on methanol with a old Hilborn...if anyone knows of one of the real early Hilborn's please let me know...

 

My last engine was a 304, french block, navaro heads...navaro intake, Literio cam, big valves etc......
very good power... I won't go more than 400jr... and 304ci is a lot, even with a french block in good shape!, on my roadster, it was very impressive how the engine rev up!
Temp get high quick! becareful.

And I won't redo a 304ci, prefer doing a 284 with a blower.

I've just bough the new Comcam camshaft, can't wait to try it!


Good luck

 

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