HEMI Tech: Camshafts.. new? Regrind? solid or Hydraulic?

I have AMC lifters in my Dodge Red Ram..
Duane

 

Gary - Yup, and it will be a little bit thicker than normal. I was thinking that I might make the washer big enough to cover the indexing dowel once it's trimmed, rather than tacking it to retain it...

 

So can anyone explain to me why .480 is essentially max lift on hemi cams(with out any extra machining). I have a 392 and i have been lookig into it and everyone says after .480" lift the springs bind and the retainers interfere with the valve guides. am i gettingthis right? I was wondering why this is so because i see bigger cams like the .505" isky cam that HHH sells. and PAW sells blower cams in the .550" range. I have found single coil springs that are rated to have a max of .525" lift. So what is the deal here or is the raised deck height of the 392 over the 354/331 make it possible to run more lift than a .480" cam. I saw earler in the thread that might have something to do with how far the valve springs can be compressed???

 

I'll offer my thoughts about the 0.480" number, and no, the .480 is not cast in stone. The .480 seems to be the easiest number to work with if you are dealing with mostly stock parts, and there is little or no difference between the 354 and 392 head in this regard. The stock valve spring has installed heights of 1.7 on the seat and 1.2 open, so you are left with 0.500". Yes, you can use a spring with smaller dia wire and gain a bit on the open number before you see coil bind, Yes, you could use a longer valve and increase the height on the seat. But a couple of warnings; do not deepen the spring seat for a tall spring, there is water down there. If you use a long valve then you must account for the changes in geometry between the rocker and the valve. The longer the valve the more that the rocker tip will be scuffing accross the top. Also, with a taller valve or with lifts above .500 you will now start seeing interference between the under side of the rocker and the retainer. Yes, you can use a beehive spring and smaller diameter retainer. If you use a longer valve, then you really need to raise the rocker arm shaft centre line to keep the parts in their happy place. All of the extra work and extra parts are available, the customer is left to decide when enough is enough.
Regardless of which company is offering which grind, it is always left up to the customer to pick the correct pile-o-parts to put together. IMHO, high volume vendors seldom care if you have a workable combination as long as your check clears.

Gary

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73RR is correct... however you are not talking killer lifts here. .480 to .500 is not all that great. The stock lifts on the early Hemis ran from .390 to .450. If you are worried about coil bind on your spring get yourself a nice vernier caliper, put a spring (s) in your bench vice and compress them to coil bind and measure it. That will tell you where not to go. Also remember the springs don't know whether the block is raised or not and neither does the cylinder head.

 

The Hemi combustion chamber responds awfully well to longer duration...

 

so coil bind is when the springs is completely compressed to all the coils are touching correct? also. lets say I ran the .505 isky cam with .525 springs i mentioned would that be too much seat/open spring pressure? cause I have heard alot of people having problems with bigger springs having too much pressure so i guess that would be for smaller cams?

 

Yes, As the name implies, the coils are 'bound'.
As for the cam profile vs spring pressure...seat and open pressures, as well as spring rate, are usually determined by the cam profile, mixed together with anticipated rpm range, multiplied by a swag factor that indicates how honest you answer all of the needed questions.
Even with a fairly wild profile, if you really drive like an old lady you can get by with a soft spring and save alot of wear on rocker arm shafts and cam lobes. If you plan to do some banzai ¼ mile work you will need a stiffer spring (as well as a rev limiter). If your spring is too big, you will likely break exhaust rocker arms or flatten cam lobes.
Your 0.525 spring may allow lifts up to that height, but it must fit all of the other parameters in order to work properly.

If you are buying a cam from Isky, then they will offer spring recommendations based on what you tell them. The swag factor.


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wow thanks alot man thats some good info. I guess i should talk with some people at Isky. I dont know how to drive like a grandma haha but yeah i understand what you are saying thanks though thats some good info

 

Here are two different styles of early hemi roller lifters. There is no id markings on either. I am sure someone out there in HAMB land can tell me who made them. Both styles are steel. I have seen the tie bar type for sale in aluminum, but no one could tell me the manufacturer.

Thanks.

 

Need a Hemi cam?? Check out this thread!

http://www.jalopyjournal.com/forum/showthread.php?p=4562607#post4562607

They will also be added to the supplier list!

 

Trying to find specs on a sig erson the grind number is RV-10H. Does any one know the specs or where I could find em? thanks

 

Is this it?...

 

yeap that'd be the one thank you for your help

 

I get good regrinds from Canadian Chrome 33 Peelar Rd Concord, Ontario, Canada.
John has done work for me for 30 years or more. Always good. I like putting the 68 340 dart stick grind on the early hemi shaft. John has done that for me. Since a 060 over 331 makes almost 340 cubes it is fun standing behind an early hemi idling with this grind. It actually sounds like a late 60s 340 . John though can do and has done for me almost anything including some experimental stuff.(Cam for the Four America vintage stock car now in Florida and cam for the Orange 72 Charger in Europe that was part of the NASCAR REturns to Lemans team as driver training and practice car.)As you might surmise from the name he also hard chromes cranks and has a booming crank grinding business as well as cam grinding. A great guy and an exceptional craftsman. Tell him Don from Belleville sent you if you like. It work hurt. He will ship anywhere.
Don

 

Any body tried a new thumper cam for a 392,they are selling 3 sizes?

 

I do believe that the 392 they are referencing is the new 6.5L, not the EarlyHemi series.
In Chryslers infinite marketing wisdom they have only caused confusion by reverting to the honored 392 moniker.

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they said it was for the old 392?

 

They're even doing 'Thumper' cams for the Ford Flathead . . . have not ran them as of yet, but am always curious. It is easy to use duration, lobe timing and the exhaust profile to create the "sound" that everbody associates with a hot cam/engine . . . just wondering if there is any performance that goes with it?

 

My buddy put a big mutha thumper in his stock 350 and it sounded good and ran decent.Was no power house, i thought it would be a dog

 

btt

 

Here are the Thumper specs from the catalog :
http://www.compcams.com/Base/pdf/09THUMPRlow.pdf

CHRYSLER 392 C.I. HEMI 8 CYL. 1957-1958
HYDRAULIC FLAT TAPPET CAMSHAFTS
Thumpr™ - High performance street, stock
converter ok, best with 2000+ converter
and gears. Choppy/thumping idle.
Hyd. Hyd. 2000-5800 26-600-7 279TH7 279 296 227 241 .486 .472 107°
Mutha’ Thumpr™ - High performance street/
strip, needs 9:1 compression, 2500+ stall, intake,
gears and headers, rough idle.
Hyd. Hyd. 2200-6100 26-601-7 287TH7 287 304 235 249 .498 .483 107°
Big Mutha’ Thumpr™ - Street/strip, needs
9.5:1 compression, 2800+ stall, intake, gears
and headers, very rough idle.
Hyd. Hyd. 2500-6400 26-602-7 295TH7 295 312 243 257 .508 .495 107°

So after talking to Chris Nielson about Hemi cams and SBC cams, he said a Chevy grind is not good on a Hemi. Maybe I don't know what I am reading but the Chevy grinds in the catalog look like this Hemi grind. Has anyone tried one of these yet?

 

Nice to see that it is for the 'real' 392...

The big difference between Mopar cam designs and most others is that Mopar uses a larger diameter lifter which provides more area under the curve. This is important if you are drag racing and need that extra 2hp or if you are building an ems package and need bragging rights.
On the street, the seat of your pants will not likely feel any difference in performance.
The 'choppy/thumping idle' is from the tight LSA. There are trade offs between narrow LSA like these at 107 and stock pieces around 114 and custom pieces at even higher numbers.
As the LSA increases; the overlap decreases, idle vacuum/quality improves, and the torque curve flattens.

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The comment about Hemi vs Chevy grinds Is the Chevy doesn't breath as well & needs the split lift/duration grind, where the hemi doesn't.

 

Anybody running a Schneider grind?

 

LSGUN, mine hasn't been started yet nor is it a Hemi, but we had the cam in our '56 Dodge 315 Poly motor (Hemi block w/ Poly heads) reground by Schneider Cams:

Valve Lift: intake .450 duration 256
exhaust .435 duration 262

Camlift: intake .300 duration @ .050 206
exhaust .290 duration @ .050 210

I really liked the time they took to go over with me what I was looking for and to give me suggestions. The cam grind is supposed to give good performance between 1500-5500 rpm's. A little lope, decent economy, and able to spin the tires occasionally. Hopefully I'll get the intake manifold fixed and the distributor soon so I can do the initial start-up.

Jay

 

Hello Hemi Experts.

I've already learned here that you can easily adapt the small block mopar timing sets to the early Hemi engines with the short-snout camshaft. I recently stumbled across a "Keyway Adjustable Billet Timing Set" from Comp Cams, part #7103. It's for the 273-318-340-360 S.B. Mopar engine. It also comes with a Torrington roller thrust bearing. The thrust bearing is the part I'm not sure can be adapted, not without having it my hands at least:

http://www.compperformancegroupstor...=CC&Product_Code=7103&Category_Code=AdjTiming

Has anyone used this timing set on an Early Hemi? Good results? Bad? My engine project is a 57 392 Chrysler Hemi, just in cast that makes a difference.

Thanks in advance for your time. Take care,

David

 

...have never used one of these (never had a 'need'), so can't offer an opinion, but I will say that the prices is right for a high quality roller chain set.
You will need to verify that it actually fits well on the 392, that is, make sure that the gears line up. If the cam sprocket sits proud then you can put a shim behind the crank gear.

Be sure to do an install thread with some pics.

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Thanks Gary,

I really like that timing set. That beefy chain is what I'm after. 1/4" pins, and noticeably thicker side links. If I go with it, I'll definitely do a writeup.

David

 

been running the A-block timing set in my hemi for years