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

This is a great thread with a lot of good information for the 354 build I have started. I would like to add some information I have collected that others may find useful. I plan on using a roller cam and have purchased Lunati hydraulic roller lifters P/N 72337-16 http://www.ebay.com/itm/LUNATI-SB-M...es&hash=item2eb5dfb7c5&vxp=mtr#ht_2575wt_1091. These are the same lifters that HAMBer 345 DeSoto has used for a few years and from him it has been determined that they are a drop in replacement for the high deck DeSoto. They are also a drop in for the 354 and therefore for all early Chrysler Hemis. The tie bar has plenty of travel. I have measured .560 of lifter travel before binding at this travel the oil groove on the lifter is partially exposed above the lifter bore. Here is some information I have found:


Cylinder bore centers
Dodge Hemi 4.1875
DeSoto Hemi 4.3125
Chrysler LA 4.460
Chrysler Hemi 4.5625


Deck Height
Dodge Hemi Low 9.29 High 10.38
DeSoto Hemi Low 9.54 High 10.37
Chrysler LA 9.60
Chrysler Hemi Low 10.39 High 10.87
This and other good information is here – http://victorylibrary.com/mopar/m-table-c.htm.
Based on the deck height of the High deck Dodge this lifter should also fit if there is enough travel on the tie bar. If someone has a Dodge block or cam and can measure the lifter bore centers I can check to see if there would be enough travel without modifying.

 

The accepted info is the tie bar is right lenth for Desoto, but too long for Dodge & too short for Chr

 

I have tried them on my Chrysler 354 and they are plenty long enough. This brand may have more travel than others

 

Now thats good to know. By the stuff I had heard him say in print, thats not a big surprise. Thanks for the heads up.

 

Tjet, I just noticed your question, sorry I took so long to answer.
Duration: in/ex=292
lift: .404"
lobe separation:109
lobe centreline: 105.
Had it done Oct 2010.

 

Someone want to school me on what kind of cam I might need for a mild street hemi? I have a 56 331 industrial that I am converting to run in a project of mine. Plan on running a 6x2 offy/97's on top, tko 5 speed into a 9 inch (haven't bought the rear end yet so don't know gearing). Nothing special going on inside because it was a low hour engine from an irrigation pump so I don't plan to tear it all the way down. Looking for a nice rumble at idle and some low to mid torque if possible

I have my eye on an isky with specs:
duration- 270/270
duration at .5- 216/216
lift- .445/.445
lobe center- 112



I know just enough about cams to get myself in trouble so any insight into how this cam would perform would be awesome. Also if anyone else has any other suggestions please let it be known.

 

With your low c/r and a manual trans that profile might be OK.

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Thanks for the reply. any other suggestions you might have on cam choice other than that isky for a pretty stock motor? I also see a few choices on HHH that seem a little more radical. how would you think something like these would do?

270@111 (.465 lift, 221 Dur .050, 111 ls) 331/354

280@108 (.485 lift, 238 Dur .050, 108 ls) 331/354

280@112 (.485 lift, 238 Dur .050, 112 ls) 331/354



like i said, i know enough to get in trouble. I looked through all the hemi cam pages and just got confused as to what I need for a stock motor to get a nice lump at idle but still be streetable. I appreciate all the help guys

 

The following is MY opinion, and I'm real sure that others will opine and disagree...we all have our own definition of what is acceptable.

1. 'Bigger' than your original Isky. Might be tolerable
2. Too big and I am not a fan of 'short' LSA. Yes, they make for a choppy idle but many sacrifices, especially with your low c/r
3. Too big for your c/r. You will lose all low rpm grunt.

Will these physically fit in the engine, yes.
Will the engine run, Yes.
Will you be happy, not likely. You don't have enough compression to effectively use a cam with duration much above 210 (adv 260). Your first Isky ( similar to our 270-218-.450" regrind) would be the best choice of what you list.
If you change compression to 10:1 then you have a dozen new profiles to consider.
With all of that said, I will admit to using an 'old-time' profile in the small Dodge that does what you want and folks seem to be happy with the operational aspects, duration is around 225 but the lift is only in the 0.400" range.

The biggest concern for you and your engine is if it truly is an original then cam lifts above about 0.420 will put a lot of stress on the old valve springs. The 485 jobs could kill it...

.

 

and this is exactly why I asked. I sure do appreciate the advise!

 

Has anyone applied a set of the new 'beehive' springs to a Desoto Hemi? I'm curious if the ones sold are close enough in size to work.

 

I don't want to drag out this conversation but I got a couple of pm/emails beating on me for glossing over the issues with big cams and that duration is not always the bad-guy. Correct. I failed to bring in the part that overlap plays (as well as using a tighter lsa in certain applications). Yes, you can have a somewhat big duration in a relative low c/r engine as long as the overlap is kept low. The problem is that too much overlap bleeds off cylinder pressure and the engine makes no power.
So, some of the profiles you mentioned could work, depending on the overlap, but the big lift numbers will still destroy stock valve springs.

Camshaft design is pretty damned complex and I don't claim to be an expert. There are days I wonder if anyone really is. I only know what has worked in the past and try to build on that knowledge.

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I've spent an awful lot of time looking at cam profiles, graphing them with software and having custom grinds made over the years. I'm sort of a "cam nut" you might say.

I would like to comment a bit about lobe separation angles (LSAs), duration and overlap. Typically when you decrease the LSA and run a "tighter" LSA, you have a bit rougher idle and you move the power-band up a bit. If you ground the same profiles on two different LSAs, the tighter LSAs will have a bit more overlap than the wider LSAs. With that said, there isn't a HUGE overlap difference just because you moved them apart a few degrees . . . it is a few degrees difference. The amount of overlap has a lot more to do with the duration of the overall profile than it does the LSA (though it does influence it). There are a lot of guys running turbo motors and sprayed motors that screw with the LSAs and they tend to widen them a bit - like 114, 116, etc..

On a naturally aspirated motor, I like narrower LSAs - mostly because I like a snotty idle and my engines are usually built to rev and make power higher up. I do make sure I have a valve train, compression, gears and lower-end designed for higher revs - all part of the package. (Just the way I like it). Also, when you put a Roots supercharger on an engine - it will tame the cam down a bit at idle in that there is some level of 'force feeding' the intake charge and it isn't 100% reliant on cylinder vacuum to try to fill the cylinder at low RPMs.

From the cams he listed down below - they are not really all that much different. Cam #2 is going to sound a bit snottier and will make power further up the RPM range. If you have a manual transmission and some lower gears, it would be "fun" . . . on a car with high gears, low compression and 6 carbs - you probably won't like it.

It does come down to the complete engine and driveline package.

Truth be told, where you're probably going to suffer the most is that running 6 carbs on that motor will probably cause it to be quite the dog. Cool for sure, but way over carbed. Also, you're probably running a "log style" manifold - which also are not good performers at low RPM.

With a bigger cam, low compression and low cubic inches . . . it is probably going to very sluggish, rich and will bog until it gets some RPMs up. You didn't tell us much about the rest of the car - it does come into play:

A) Weight of the car
B) Clutch Type
C) Flywheel weight
D) Gear ratios (trans and rear). Tire sizes
E) Any other engine mods? Just carbs and cam? What about exhaust?
F) What is the intended use? Just running around town? Highway? What?
G) Carb linkage - progressive, 6 at once, etc?

All this stuff together will help folks make recommendations.

 

I don't know if Howards cams (Wisconsin) still does custom early hemi grinds, but if you have the coin for a billet roller for your Desoto, Don Johansen (Howard's son) can grind you one from tool steel when he has blanks. try 909-815-9185. Plus you get experienced advice for your application. No web site, no credit cards, just good ol boy experience.

 

I used Racer Brown on my recent 32 Ford Coupe build. He was very helpful and nice to work with. Mean sounding little Dodge Red Ram "Baby Hemi"! His name is Jim Dowell at 410-866-7660. Eric at Hot Heads for most parts too.

http://www.jalopyjournal.com/forum/showthread.php?t=862612&highlight=32+spitfire

Todd -32 Spitfire
High Noon Speed Shop

 

Cams are like exhaust systems - I think the people who really understand them are far and few between and are usually working for a company with vast resources (test and R&D) such as GM or Ford.

I get un-excited when I hear of smaller cam companies that can grind 'em like they used to 50 years ago. That just tells me they have not advanced in 50 years. Maybe their cam will run great, or maybe it will leave 5% HP on the table. I'll bet if Comp Cams spent a few hundred grand on Hemi R&D you'd see some good gains....

 

Hey that's so cool...PM sent.

 

nzhotrod,

Here is a better photo. I forgot to mention the Ross 10/1 pistons too.

Build link: http://www.jalopyjournal.com/forum/showthread.php?t=862612&highlight=32+spitfire

Thanks!

Todd (32 Spitfire)

 

5% would be important if you're racing, if you're not then lots of potential HP is left on the table with every streetable build.

 

High lift cams will also eat up valve guides, especially the intake guides.
Use a bronze guide and the problem gets even worse. I tried that just once, got only one season out of the valve job, and switched back to sintered iron guides a year later and never went back. That was back in the late seventies.

 

You'd have to do a lot more explaining before that ever made sense to me....I'd wager that improper valvetrain geometry and improper lubrication wears our valve guides way before an extra .075" lift ever does. And why it would be any worse for intakes also is a mystery....

 

The short length of the intake rocker drags the rocker across the top of the valve stem. The farther you open the valve, the greater the deflection. This creates more side load against the valve guide the further you open the valve. At 10,000 to 12,000 miles, there's enough wear in the guides that you can wiggle them with the springs still installed. At 30,000 miles, the guides are shot.

The exhaust valves, with their longer length, aren't as prone to this valve stem displacement.

Stock valve geometry, too, btw.

 

I'm gonna bring this thread back up again...maybe some of you can help me quit beating my head against the wall, and perhaps that information will prove useful to someone else too.

I'm going racing. On a budget! So far my plan for the 331 Hemi in my '30 A Coupe will be doing dual duty on the drag strip and more importantly (to me) will be some entry level (and maybe faster, later) land speed racing. Without going into a TON of detail, let's just say that all of the supporting components are in place, and I am stuck between two cam profiles, both solid rollers from Crane.

Cam #1; the safest profile is a 246° @ 0.050" with 0.495" lift. Add in 0.020" lash and I'm right below the magic 0.480" lift "limit". I know this cam will work, I know that valve train geometry and valve tip scuffing, and all the other maladies that come from pushing lift past 0.480" will not be an issue, but I'm hung up on...

Cam #2; the cam Crane's Chase Knight actually recommended for my motor combination is a 250° @ 0.050" with 0.550" lift. Chase recommend 0.025" lash, leaving me with about 0.525" lift. I immediately protested his recommendation, citing the magic 0.500" "limit", and Chase quite plainly said the additional lift will be a non-issue. I don't mean to second-guess the man, but evidently he hasn't read these threads.

Now, I've talked with Bob Mckray (he's building the heads for me), and he said "no problem", and set off finding springs and valve lengths to accommodate the higher lift, but he's not the one who will be dealing with setting up the rocker arm geometry.

Now, my question is, and keeping my budget in mind, will that extra bit of lift and duration (0.050" and 4°) be worth all the extra hassle involved in making it work on a 331" race hemi that's being built for wide open, high rpm performance?

I imagine Bob Mckray will be maching down the guides and opening up (out not down) the spring pockets. I don't imagine it's too late to spec a beehive spring. Can I just simply shim the rocker stands up a few thousandths and "Bob's your uncle"!?! Billet stands and fancy roller rockers will effectively shoot my budget all to hell. And I want to run a stock valve cover anyway (with some of Tom Waters' spacers to clear my adjustable rockers). Thoughts?

 

X2 not a fan of bronze guides unless the head is aluminum then only because of the expansion rate of bronze and aluminum are closer than aluminum and iron.

 

I need advice for a 331 Chrysler roller cam that will work with a 6-71 blower and manual Trans on the street. I like the rough idle and will be running pretty low gears. 5:38 with a 6 speed trans

 

Has anybody have any experience with TNT Hemi Engines in Arizona? I just bought a cam from him and I'm very happy with it.

 

Anyone have any experience with any of the current Howard's cams? I'm looking at the .470/221/110 they have listed in their catalog for my 392 build. I feel like it could use a little more duration, but I think I would be happy with this cam.

10 to 1 hypereutic pistons, k1 rods, mild head porting and smoothing, hot heads intake, modified headers to fit the 57 desoto and a 750 Holley. I'll be backing it with a built wide ratio (2.74/1.54/1) 904 trans and 3.23s or 3.55s. I want a good street motor that can do 75 on the highway all day while still scooting around town.

 

I am going to drop a flag on the play: your 904. It can be done but all of the 'usual' adapters will require a 727.
The difference all centers on the 904 starter sitting ½" higher than the 727 and it then hits the block.

Your cam selection would be a very happy street piece and yes, you could easily go to 230 @ 050 if you have a 3000-3500rpm converter.
As of this week there are some new cores at the various 'big-guys' shops so you do have some other cam companies that you can also look at. Schneider, Isky, Engle etc.

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Whenever I read this stuff on here, I wonder how many of these guys just sit down and think about how changing a given spec Changes the actual valve events. None would be my educated guess...
Maybe we need to go back to the good old days, where cam grinders didn't even publish duration and LSA numbers, they would just put the valve events in the catalog, and if you wanted to know the duration and LSA, you would have to calculate it. Would sure eliminate most of the bs you read, cause my guess is, most guys couldn't do it.

 

Thanks for the flag, I jus saw your other posts on the 904 in some old threads. Back to the 727 or a 518 if I can grab one. Thankfully I didn't have a 904 yet. I'll miss the 2.74 first but eh, if I can get a 518 I'll run 3.55s or 3.73s to make up for it. Would a clockable starter help with the 904?

Thanks for the info on the cam, I'm excited for this to come together, I think it's going to be an excellent street combo.