flathead cam advice

I'm building an 8BA street motor and I want it to have a tough ballsy cam, and also want it to be street friendly. I'm looking at the Isky 400JR but some say it's too much for my application. It's got a 3.24 bore hypermax pistons with 4" merc stroke. Offy heads and intake with dual Stroms and I'm probably gonna put a C-4 behind it. The other cam I'm looking at is the Isky 88. Anyone out there with experience in this area, I'd greatly appreciate any feedback.


Peace

 

My machinist talked me out of the 400JR, and convinced me that the MAX1 would be much easier to deal with on the street. That might even be more of an issue with your automatic. My cam specs are .350 lift and 249 dur, compared with .400 lift and 258 dur on the 400JR cam.

But having said that, i think the 400JR would sound badder. Is that a word? haha.

 

My father installed a Isky 400jr cam he had been saving for years in a 276ci eng with Edelbrock heads and dual intake and didn't like it. Low vac levels and he had to install adj tappets with "thin" heads for clearance. He ended up installing a 77B grind which I think is Isky's 3/4 race grind. Not lopey but he's happy. He also had very good luck with a Moon Super 3/4 race grind in another eng. 360 lift,270 duration.Little more lope. I had Bill Jinks at Moon grind me a standard 3/4 race with 329 lift,256 duration which is simliar to the Isky 77B. Moon regrinds are about $ 100 cheaper. I haven't installed my cam yet ,but in this day and age when can you actually meet the machinist who grinds your cam.? That alone is cool and worth the trip.

 

400JR is the only cam in my eyes....!
built many flats with that cam from wild to just a stock F.H. without and changes except a 400JR

 

max 1 is what you need.

 

Ok, first post an intro.

Second, what kind of car is it going in? The weight of the car will make a big difference in what you can and can't get by with. I doubt it's your flathead powered '68 barracuda

 

Exactly, if it's a heavy car with the automatic, I would think the Max1 would be a better choice because it would give better performance at lower RPMs. Just a thought.

 

I have a 286 motor in a light car, I run a Berry 400jr. it has .410 lift, adv 295, 242 at .050 Runs great. Be sue to clay the heads. Berry will regrind your cam for cheap. PM me for a phome number.

 

Check my intro, Sorry. It's going in a 30's style RPU, it will be light. I won't be taking any long road trips or sit in traffic endlessly with it. I've heard some flatheads remind me of an old Harley, that's the lopey sound I want. I'm leaning toward the 400JR but I don't want to be asking for trouble.
Anyone using Edelbrock heads and intake.
Peace

 

400JR is a bit much, especially in front of an auto - it's also hard on the valve train. Check over on Fordbarn - do a search for cam & read for hours.

77B - don't waste your money - it's nearly stock. If you're having doubts about the 400Jr, go with the Max-1.

Personally, I think for the auto, you'll be better off with a Max-1. It will have a lope to it & if you're really after the "harley" sound, just turn your idle down a bit...

As for Edelbrock v Offy heads & intakes, it's a tossup. QC in both is down, with Offy having more issues I think. Regardless of your choice, be sure & clay your valves if running a big cam...

 

Hey Ernie,

So whats the biggest issue do you think, duration or lift? Is the 400 Jnr hard on valves because of its lift?

I've heard endless good things about the L100 from Cam Techniques. Everything from stock to souped up hotties and it seems to run fine. The Potvin 3/8 is also supposed to be a hot cam but easy on the lift. I'm toying with going either the Potvin 400 or 3/8 in mine.

Danny

 

May I make a suggestion? Everyone that I know of that has run a slush box behind thier flatty has been disappointed. Not saying it cant be done well but thats the feedback I've got.

Lets face it, flatheads are not every going to be torque or HP monsters and in order to get the best drive from them, we need to get as much power to the road as possible. Go for a manual, preferably a 5 speed. The over drive will allow you to run 4.11's and get excellent highway milage.

The other issue is, due to the low revving nature of the motor, have a 5 speed really allows you to select the right gear, all the time. This means you can run a bigger cam and keep the motor in the right rev range to maximise its power band.

Danny

 

That's good advice from Psychobilly, I wouldn't use an automatic either. A T5 ****** is a really popular choice, that's what I have my eye on. I think a T56 would be even better, but I don't know if there are any kits out there.

If using a T5 in a pickup, you need to use the style out of an S10 pickup, so the shifter doesn't stick out under your seat...

 

I'm with psychobilly boi on the auto - I think the flatty is better suited to rowing the gears. There are a few exceptions, of course, but.

As for the anectdotal evidence of the 400Jr being hard on valve train, I believe it has to do with the acceleration of the lobes being very abrupt - visualize an oval vs an egg - the vertical component happens very quickly.

So it's not overall lift, but how quickly it gets there - a combination of lift & duration.

 

M-77 and 77-B probably aren't the same grind. An Isky 88 would be cool with a stick shift.

 

5 speed, just ask me !!

Rat

 

The subject of flathead cams is like opening up a can of worms... everybody has their favorite and some work better than others. Ron H likes the L-100 from cam techniques, 286 likes Schnieder etc. I recently did a mild street engine using the Max-1 in a 40 coupe; the customer was very happy. The lifter acceleration rate on the 400 is pretty high... I have removed these from old circle track engines and found significant lobe wear. Call Chris Nielson out in Utah (sorry at work don't have the number) and discuss your needs: he has done cams for turbocharged flatheads up to drag race style configurations... he is also willing to mix profiles on the intake and exhaust to fit your needs. He ground two different profiles for me on a street cam and the low end was very good... happy hunting ...fats

 

Good Stuff Guys, this is the 1st motor I've ever built; and for some odd reason I chose a Flathead. So far so good, I'm having a ball working and learning. I have a machine shop here in Vegas that will be doing my machine work and he has built Flatheads before. I will get his opinion but I wanted to be armed with all the info I could find. You guys have given me alot of good info, and my initial plan was to put a T-5 behind it; but I started thinking about being lazy so I thought of the C-4.

Peace

 

53Ash had his machinist regrind one for him for like 40 bucks and it freaking rocks. Might PM him for more info on it since he doesnt get on but everyo other day or so.

 

Here's Chris Nielson's phone # in Farmington, Ut.:801.451.7745 Be patient, he will return your call. He's had some health problems lately so he's not at the shop every day.Best bet is his email:vintagecams@juno.com He just did a cam for me that he called his hot 3/4. Its in an 8ba thats warmed over, and I love it! I think its close to a potvin grind. Hope this helps.

 

Kevin, at the risk of being redundant, there has been quite a rash of camshafts going flat recently. The current practice recommends breaking the cam in using Diesel Compatible oil; it seems that the Feds have mandated removal of zinc from automotive oils for environmental purposes. Zinc is still utilized in the formulation of Diesel oil and provides extra lubricity at the lifter to lobe contact area...bear in mind this is for break- in only ... usually 15 to 20 minutes at 1500 rpm will do it. The Max 1 isn't that aggresive so if everything was up to snuff on the set up you shouldn't have had problems. Chevrolet also still produces their EOS which was developed specifically to break in the old Duntov cams... I've used it successfuly also. Hope this helps...... fats

 

Hi Guys,

This zink issue is a big deal over on the fordbarn site. Whats the real story?

Danny

 

Kevin, what were the symptoms when your cam died?

 

Fordbarners swear the Shell Rotella still has the zinc in it - I haven't checked & am running Valvoline in a stock engine...

 

What brand is the Max1 cam?

And maybe someone could give me a quick rundown of cam regrinding. To me, it doesnt make sense that a stock cam would be able to be reground to something hotter, just something smaller ? I must be missing something because if you are removing material I dont see how you can get MORE lift/duration? Please help on this if you can, or point me somewhere.

 

Kevin, what oil will you be running? What happened when you tried to adjust the valves?

 

Psycho, I'm not a lubrication engineer but as I understand it zinc was utilized as an anti scuffing agent for areas exposed to sliding friction and not being lubricated by pressurized oil. If you calculate the load at the lifter to lobe contact area it turns out to be one of the highest loaded areas of the engine ( even with flathead valve springs). The best corrolation I can think of is the relationship of lead in gasoline to the valve and seat; lead "cushioned" the impact of the valve on the seat and zinc provides a "slippery" cushion at the lifter contact area. I was under the impression that Rotella still contained zinc also so try to find out more. The EOS I recommended contains molybdenum disulphide and provides the same characteristics as zinc; I think we should remember that lifter to lobe contact area is splash lubricated and the pressure AND volume of the oil pump must be sufficient to supply this area. Even with the relatively low spring pressures on a flathead, the cam should get new or resurfaced lifters whenever a change is made. fats