I've received one of Schumann's 1957 spec cams, used in the 245 HP 312's. I think it has teh same specifications as Ford's but need to verify since nothing came with it. According to the Eichert book it is part number B7A 6250B, with a 256 degree duration, and lobe lift of .272 intake, .285 exhaust.
Now my rookie question: Is it worthwhile to degree in this very mild cam?

 

Thats a loaded question! In the past you were pretty safe trusting a well known cam grinder when installing one of their stock cams. Degreeing became necessary when playing with one off exotics or going for all out performance blueprinting.

Lately however Ive been hearing horror stories of customers getting misground junk. I buy Schneider for flatheads and a few Mummert for Y's and havent bothered altho many builders do it every time. Be interesting to hear other comments. Thinking of a Lunati for the next one.

 

Thanks Carl, I hope someone else responds too.

According to Verne Schumann this AM, the cam is based upon Ford specs of 1969, when the 245 HP Y replacement cam was changed. Rather than 256 degree and lifts stated above, it is 258 degree with only .262/.262 lift. He also added that it's resulting valve lift was .420/.420. I questioned him on that one, since my calculator says the valve lift would be .403. No adequate response.
Regarding degreeing, apparently no offset keyways are available and they will have to be made, or one of the roller chain sets used with built in adjustments. His thought was degreeing would serve the purpose of advancing cam 2-4 degrees to make up for future timing chain slack.

No one including Schumann and myself seem to be enthusiastic about this grind (it came up in a brief discussion on y-blocksforever a while back). Since my objective is a little bit of over stock 292 power and a lot of MPG I'll stay with it, and therefore think the degreeing should be done to achieve optimum timing, assuming that advancing or retarding would only hurt MPG (right or wrong?). If it is too boring, installation of a replacement wont be too bad in my rig.

Back to the timing sets. I had forgotton and reread that Ford had an HD roller timing set for trucks. Does anyone have this in use, and is it less prone
to stretch than the standard sets?

Finally a question on matching motor components. Given this motor when finally together will have at least a 9.7:1 compression, popup pistons with .007 clearance, the above cam, 113 heads, 2V carb, Blue Thunder intake, and 301 cu. in., all combined in a light vehicle with 3.00 rear, am I going in the right dirction or wrong for MPG? Heads and intake are in the "must use" category.

How high can compression ratios go on premium pump gas?

Mike

 

Oh, now ya just knew I was gonna jump at this one, didn't ya??

I degree everything, even if it's a bone stock replacement. There's some junk out there....never quite know where things are made anymore. Even the big name grinders screw up every once in a while, though it's rare. I check every lobe, every cylinder, but a lot of guys do #1 & call it a day & are just fine. I've posted on this before, but Lunati are good folks & I've had good luck with them (and others).

My calculations show gross lift of .403 w/1.54s....before subtracting the lash... hm.

I don't know offhand if any offset keys will work...but offset bushings probably would. A little cheaper than the Rollmaster. Is that Ford HD set available in any form/vendor, still?

As far as MPG & adv./ret. the cam, what gears are in the axle? Depending on the gearing, tire dia., weight, power curve, blah, blah, blah,...advancing will sometimes help a tad. Depends on where you mostly drive, city or highway. Your right foot is the biggest factor, anyway. Edit- saw the 3.00. I figure your '46 weighs 3000-3100 lbs, maybe less. You should have enough low torque to get it moving smartly, even with the 3.00s.

With a stock link or Morse chain I go maybe a half or 1 deg. advanced just to cover stretch. I pre-treat rollers to eliminate stretch & it seems to work well. Doesn't seem to help link chains, but I think the pins wear more than the chains stretch.

I think you're on the right track. I wonder if you might want to mill the domes a bit to drop compression. You know all about quench so no issues there, but that cam duration (I'm assuming it's "advertised" or gross) may be a touch short with 9.7 to run pump swill, even premium. I'd probably polish the domes & chambers & c.c. it again, to eliminate hot spots. I'd prefer maybe a 9.2-9.4. As a VERY vague rule with older wedge chamber designs like the 113, you kinda shoot for a ratio equal to the desired gas octane (as figured in the U.S. as {R+M}/2 ). In other words, if you want to use 92 octane premium, you shoot for around 9.2-9.3:1 compression. That's assuming durations of around 205-215 degrees @.050 for a 350, or 195-205 for a 302. More duration allows a little more compression; but not much more duration with a 301ci displacement. The (relatively) small bore works in your favor.

Let me hasten to say, before the crap hits the fan blades, that there's nothing scientific about this, it's just a guide. Doesn't apply to Hemis, hearts, Twisted Wedges & other chamber shapes, or aluminum heads.

What ignition do you have? I've forgotten. A Pertronix IIRC.

Sometime down the road when the wallet recovers, I'd love to see you try a Holley Pro-Jection or F.A.S.T. system & pick up another 2-3 mpg.

There's a lot of guys with 20 yrs. experience that haven't figured out what quench is, what it does, and never will, so I think you're past the rookie stage.

 

IMO, the modern era of head design started with the 55-6 Packard. In 64 it was still so good that Chevy bought the rights for the Daytona porcupine 425 which became a tamer 396 in 65. My 396 has "advertised" 10.5 cr and it runs just fine on 92-93 octane.
Couldnt do that with a Y Block.

Going to be fun to see how my 58 430 responds to this panther **** swill.

 

Thanks for the posts. As always, they make me do a lot of thinking. The driving is about 75% highway, since we live out of town. Weight, with hood mounted, a spare and road tools is 2800lbs. The Pertronix is still working! Even though it would be 2 years down the road, the Pro-Jection sounds interesting. I've been looking at that section in the Holley book. Sure wouldnt want to go to the time and expense without any mileage gain though. They say briefly that it CAN (not will) result in a 10% increase.
I dont understand the cam duration being too short at the higher CR to run pump gas. It seems like a shorter duration would be more likely to run on 92 octane, since a longer duration could increase dynamic compression at higher rpms. Along this same line of misthinking: If you used 1.43 rockers and thereby decreased the .403 lift, would that decrease dynamic compression through an emphysema effect, perhaps allowing the running of pump gas in a motor with otherwise higher cranking or calculated compression?
Somewhere I read about a Y with minimum quench, emphasis on quench, which was able to use a CR of 9.5 to 9.7 on regular without detonation.
How do you preheat the rollers and to what temp? Baking? Verne Schumann lists the Heavy Duty Ford Roller set, for $70. That gets close enough to the aftermarket roller set to make a person go for the ease of cam timing.
Regarding Verne Schumann. He apparently helped right the Eichmann book, and appears once in print as having come up with a homemade solution to nonposted G heads blowing their tops under high compression. He has one page of Y related stuff, but is heavy into Chevy.
286Merc, if your 430 is making progress, how about a post on how it is coming along?

 

46,

I'll try to keep this short as I tend to run on. (Reeeaallly??? )

1) Pretty light weight. Good deal, I like it!

2)As they say, carbs are a compromise. I would compare a carb vs. EFI to a three-speed vs. a Richmond 6 speed. They both work, but the six speed is more flexible in situations & you're closer to the right gear at any given time. If you are thorough in setting up a carb, you can get pretty close, even more so with something like a Dell'Orto or one of the Webers which are all nearly infinitely adjustable. 10% overall could happen, go from 15 to 16.5 mpg..... You might also investigate using a common junkyard throttle body, junkyard injectors, & a F.A.S.T. controller, or maybe a 5.0. One guy did his 351C for something like $400, not counting welding bungs into the intake. EFI is sure easier to start on a cold morning!

3) A longer duration (depending on opening/closing points & LSA) tends to "bleed off" more cylinder pressure at lower rpm, compared to a shorter duration. It doesn't necessarily increase dynamic compression at higher rpm, in and of itself; just, less pressure bleeds off at higher revs.

It MIGHT increase the amount of fuel/air mixture at higher rpm (at least, that's supposed to be what happens!); but again that depends on how suitable the cam is for the application. If the specs are just horribly mismatched for the engine, then maybe not, if you're still bleeding off pressure somewhere, or the heads/intake/carb won't cut it. Oversimplified, but you get the drift.

Anyway, the longer duration bleeds off some cylinder pressure down low, which can help, especially if you are putting a load on the engine at low rpm (like getting a heavy vehicle moving, or having a low stall speed converter with an auto trans, or both).

4) The 1.43 rockers- now, there's a deceptively simple question. The answer is, it might...or might not...depends on a lot of things, head flow among others. I doubt it would have much effect on the average Y, but a larger displacement would be more noticeable. One possibility is that the mixture may become unnaturally lean in certain cylinders. Another is that the overall velocity of the intake passage may INCREASE, filling the cylinders more effectively (before it runs out of breath early). My personal take on this would be that it's a crutch, used when a person didn't want to/couldn't spend the coin to re-cam or alter the compression in something they just built or bought. There are some interesting reasons to do this in racing, at times, & if yer interested, the Isky web site has a tech topic about doing this in order to crutch an incorrect cam (while waiting for an Isky custom grind, no doubt. )

5) I hate to touch this one, because, it just depends. Anymore, at 40, I take everything with a grain of salt, unless I've seen it for myself. A couple of thoughts though: A) Too many people don't know WHAT they've got (or figure it's "11:1, 'cause that's what the piston box said".) B) That smaller bore size helps. C) Quench is such a subjective thing. It's more important where it occurs, rather than how great a surface quantity. Some of the 460 guys are running dished pistons with only about a 1/4" or 5/16" band around the outside of the piston head. But, you still get the effect on the far side of the chamber (with most 460 head designs) and they do just fine. D) Some chambers are more effective than others. I've mentioned the 4V CC Cleveland chamber, which seems to tolerate ridiculous amounts of compression on pump swill. The 2V OC Clevelands are a different story & results are mixed; the guys who make them work are very attentive to detail, or have mild combos, IMHO. Carl mentioned the 396 heads, & I think his is a '65 or '66 Impala, which has the "closed" or bathtub chambers. Those have pretty decent tolerance to detonation, & I've had luck with them at close to a true, measured 10:1. I did, however, use different plugs for racing & street use, and, eventually, different plugs in the "good port" cylinders & the "bad port" cylinders.

You may be just fine, especially with the light weight. I'm a worrier. One possibility would be to carry a can of octane booster, like Moroso's, for emergencies on the road when you're away from home & can't find 93.

6) Wait for the wife to leave, take a pan, use oil with some moly lube stirred in, & simmer for an hour at 200 deg. Kinda smelly. It works, I don't know exactly why. I think the moly may get into the pores of the metal & decrease initial wear???? I dunno. It doesn't seem to do as well on link chains.

7) Yeah, Eickman used him as a credited source. I couldn't say whether or not he was the first to pin Y heads, but that technique has been around for a long time for blocks & heads, since the '40s at least. Cleveland blocks & heads were commonly pinned for NASCAR use (due to the paper & toothpick construction of the 351C) in the bad old days. We pinned a Hemi block in much the same way, with a bolt, tap, & sealer.

 

Well hell. Anybody need at cam? It sounds like I'm back to either looking at the 260 degree Isky grind, or staying with the current 270 degree .460 lift. Can a cam with 3500 miles on it be put into a motor that has new lifters?

 

I called Schumann this AM. He used to work at Jahns and has the recollection that the Domes on Jahns 292s were 12-14 cc. His suggestion is to recurve the distributor so that the advance comes in late, transitioning smoothly to 34 degrees total, all being in by 3500 rpm. Once he said to have the initial timing be 6-8 and later 4-6 degrees, so 4-8 degrees. Eliminate vacuum advance. Cut dome height down to new height of .075-.100. Retain 245 cam if the above is done, if MPG is an objective.
Zig Zagging to a conclustion LOL.

 

Hey Mike,

I've been mulling over all this for a few days (busy at work). I was going to suggest essentially the same things- keep the pistons & mill 'em a little, keep that cam, & look at the advance curve.

It will be interesting to map that particular cam, either in the block during assembly, or even in v-blocks- you have to be very particular about where you place the indicator, & its angle. Assuming it's close to specs, I'd keep it rather than change, I'd bet it's a pretty good compromise.

In terms of advance, I might look at it a tad differently than him. Do you have a good idea of what your cruise rpm is in high gear, at the usual road speed? And, are you keeping the existing tires (tire diameter)? It's possible that you might want it all in a little earlier. I'm guessing you have the later dizzy (sorry, my memory is full up nowadays ), so a std. curve kit will work & you can play around with the advance rate. As far as the vac., I'm inclined to keep them as a rule. You can disconnect it to start, then hook it up & try it. I'll have to check but I think there is still an adjustable vacuum canister available for it from Crane or Accel. I've put restrictors in the line before, like a carb jet, but it's trial & error. Just takes time....You can start out with 4 degrees & work your way up; it might be a touch doggy off the line with 4, but better safe than sorry.

Is the 9.7 pretty accurate, with your head c.cs, or are you extrapolating? Might find that it's a little less once everything is mocked up. You can adjust the dome height pretty much any time until the end.

So far as old cam/new lifters, depends on who you ask. Essentially, you are breaking it in all over again, but with less of a Parkerized coating on the lobes. With something common, I'd just replace it, but with a Y, it's a judgement call.

 

One thing about the recent feedback from V.S.: I felt he was trying to give some ball park figures with the objective of roadability, not reach any point close to optimum. That is going to be up to me.

The road rpm is a good point that had briefly occurred to me too. 60 mph is 2000 or 2100, forget which. So it does seem like advance should be in before 3500, as I take it to 3500 or more infrequently. Tire diameters are locked in.

He was concerned about the additive effect of the vacuum advance to mechanical, thereby producing more than 34 degrees, perhaps 40 or more.

9.7 CR isnt a done deal. I'd calculated it out using different quenches, given the heads are now 69 cc. It kept coming out high. Actually higher than 9.7. I'll go back at it using the desired quench and given combustion chamber vol. and plug in different dome volumes. Still going to do the dome impression and measurement in clay. There is a significant difference between VS's recollection and my measured calculation.

Another objective of this venture is to retain as much compression potential as possible, should conversion to E85 become necessary. In other words, if in the future after the motor is up and running, to bump up compression for the ETOH all I should have to do is cut heads. But if I mill off the domes of the pistons excessively during this buildup, some of that potential will be lost.

These are all of the specs I have on the 245 cam:
197 deg. intake duration
12 deg. BTDC
Closes at 29 deg. ABC
Overlap 23 deg.
Exhaust 34 deg. BBC
18 deg ATC
Lash 19/19
Lobe centerline 110 deg Int
116 deg. exhaust
258 degree advertised duration
.262/.262 lobe lift
Since this seems to be an incomplete set of data, Mummert's cam analysis service is available. It is maddening that I have bought two new Y block cams, one with incomplete specs and the other with virtually none (the Bowman cam's ONLY known spec's are 270 duration and .460 lift).

My wife and I are taking the truck on a jaunt this weekend up the interstate to a couple of happenings, a Celtic festival and an old car event. Except for sucking large quantities of gas, the truck is running great, with one exception. There has been an oil leak which has been hard to locate. The oil apparently blows off the rear of the DS valve cover to the lower half of the flywall, then migrates down and around, making it appear it is coming from somewhere else. At least the clutch and brake pedal pivots are keeping well lubricated. It should be an easy fix after we get back.

Things could be worse. I read a post from a guy with a 1957 Olds (one of my favorite cars). He is getting 8 mph. Maybe that is why I see so few 57 Oldsmobiles.

 

I just talked to Mummert about his analysis of my new 1957(ha!) spec cam. It is not even close, but the closest thing it does matche is a 1964 truck cam. So beware, these cams are totally misrepresented.

 

Ouch....any chance of a refund or exchange? Should be...

I wonder where he's getting his cams from.

 

Refund or exchange? I will be pleasantly surprised if those options come about. The cam should be back this week. Hopefully Mummert did a full analysis and didnt quit early, wondering "what is the use of this". I would like to have a good set of data to look at when the phone call is made.

 

Good news. I was granted an exchange credit on the cam for a set of rod bushings and rings. The cam is on its way back to the shelf in Iowa, and the Jahns pistons are in transit to Sweden. Good old flattops are here and an Isky cam on order . And there is more...the machinist finally started on the block!