[Chrysler300] RE: Uplifting Cam Questions
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[Chrysler300] RE: Uplifting Cam Questions



Hi Rich,

 

My .02; that cam is perfect. Don is the pro here, but Comp is the best cam over and over, in many runoffs:  I watch this stuff. The other good B block ones seem to be from Hughes (Amsoil engine challenge in MOPAR mag) .

 

The big parameter in this,  is the total area under the open curve, not just lift and duration raw figures. Today’s cams are computer optimized,(thus Comp Cam) ; so faster lifts and faster closing means open % is higher more of the time, open full sooner,,equals more power, without more duration. . But 268-270 is not an overly aggressive cam; the 300D was 280 ,and 440 challengers were 280 intake I think. 268 to 270 is not significant. 

 

Comp cam overall 2014 grind is probably far superior to 1964 factory grind. With no reduction in vacuum, etc 

 

300 J/K was quite a package, with 268-270 cam matched to ram peak impact, so significantly more or less cam makes no sense. On my J , I made the mistake of a shift kit in 727,which raised shift points , but they were already high with J governor, giving ridiculously high RPM shifts and tossed belts (2-3 at 105 mph); so mother knows best...leave the package as designed. Especially for mainly street use.. J converter also very special, allows higher idle this cam likes.

 

Marks on pistons are probably from over rev,( J does that! “holding 2nd!”) )  there should be plenty of clearance, you can check that easily by seeing how much more is available (clearance) by pressing down valve more at closest approach, with light checking spring, or if an open engine , with clay. Given 440 had even more,  probably fine .

 

I would keep all stock, check springs for any weak ones on valve spring tester, to spec. ; reassemble with old parts, old dampers, or NOS. Valve float on J is way up there.....stock. You will never be up there, it will upshift, unless you make mistake I did.

 

There is a school of thought that a stock head wedge from Chev or mopar  is long dead at 6k or so anyway, (breathing) but hemi can keep going, why 392 is 280 ; this appears as a big aaaahh flat spot at 5500 or so,....and it tells you “time to shift”, or , better, you should have already ; the point being no need for heavier springs to go 7k. No torque . Changing springs upwards can lead to coil bind, other problems bent push rods etc etc although a comp cams kit will be OK. Beehive springs are hot set up now. 

 

It is also a reality that our cars are no longer “fast cars” 0-100 compared to say a 2013 Hemi 6’ ram truck. So going out on cam timing etc not appropriate for present 300 purpose, can destroy drivability, kill gas mileage and still not be “fast cars” ---hate to say it, but this reality dawned on me a while back. Of course a 650” wedge in an F or J with 4;56 would fix SOME of that.  (Spirit of George talking) 

 

The Hot Heads 380” 1956 354 hemi that won or came in second in the street engine category hit peak at only 5500, (650 HP and 650 torque...take that,  big block Chev)  and beat 2- 426 dual quad hemis, and a cammer Ford, and many 500” BB chevs , with plenty of vacuum and good idle . I have been trying to find out cam spec in that. Damn, that Bob Walker IS good. That engine with all the Hot Heads aluminum stuff (heads etc) weighs less that a small block iron Chev,. Unbelievable. Should be in a C300. 

 

John

 

From: Rich Barber [mailto:c300@xxxxxxx] 
Sent: Tuesday, January 07, 2014 2:19 AM
To: 'C Bilter'; Chrysler300@xxxxxxxxxxxxxxx; 'John Grady'
Cc: Chris Pinder; Don Cole
Subject: Uplifting Cam Questions

 

I continue seeking guidance on a replacement camshaft and related items in our ’64 300K ram engine.  The existing camshaft had a lot of pitting on the lobes.  I want to retain the solid tappets and adjustable rockers and find a cam that will provide operation and performance similar to the original.  I want decent idle, good vacuum and good drivability..  I found the below-referenced pages on the club website to be very thorough and helpful and went back to looking at the multitude of cams available.  I found the Comp Cam at this website to come closest to the original specifications of lift and duration:  http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=725 <http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=725&sb=0> &sb=0 

 

This is what COMP says about it:  Solid-Good with stock converter & comp. Near smooth idle in 440. Works good with 650-750 CFM carb. Excellent torque.

 

Specifications (Intake/Exhaust):

                              Comp                   Stock-AMA Spec’s            Stock-Factory Drawing

Duration              270/270               268/268                              268/268

Lift                        .468”/.468”        .445”/.452”                       .444”/.450”

 

I claim no experience or insight on camshaft selection and did not find any other mechanical-lifter cam with anything closer.  Everything else had higher lift which I guess might produce more horsepower, less vacuum and rougher idle.

 

So, I ask:  

·         Does anyone have actual good or otherwise experience with the referenced COMP cam or any other replacement camshaft for a ’63-’64 ram engine?

·         Does the slightly higher lift put valve interference with piston tops at risk?  I did note a few nicks in the piston tops of the ’64 300K engine from the parts car I bought.

·         Any experience issues with COMP cams in general?

·         Since I have a factory drawing for the cam, is there any interest in having some precise replacement cams ground?  The factory drawing has lift to five decimal points at one-degree increments.

·         The 300K Supplemental Service Manual shows valve and valve spring specifications http://www.summitracing.com/parts/cca-k21-246-4/overview/           I found the comparison of valve spring loads between the hydraulic-tappet Firepower 360 and the mechanical –tappet Firepower 390 engines and the with the same indicated 0.430” compression to be interesting and am wondering if ram-spec valve springs are available or particularly necessary?   AMA specs and factory supplemental manual specs differ slightly, possibly due to typo(s).

·         And, are the spiral-type surge dampers that fit inside the valve springs common items and readily available?

 

Summit carries this cam with optional lifters and valve train items:  http://www.summitracing.com/parts/cca-k21-246-4/overview/    

 

Thanks and best wishes for a Happy, Healthy, Prosperous and thoroughly C-300-K’ly New Year!

 

Rich Barber

Brentwood, CA  (Convertible weather here)

 

 

From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of C Bilter
Sent: Monday, January 06, 2014 9:41 AM
To: Chrysler300@xxxxxxxxxxxxxxx; John Grady
Subject: Re: [Chrysler300] Cam specs different years.

 

  

John and all-

 

The attached from the club website is an old article but might be helpful in addressing some of your questions re. the original cam specs.  http://www.chrysler300club.com/tech/cam/gk.html    And, yes, you would be correct that the J cam would have been a little “hotter” than the F (375 hp  hydraulic) cam as far as lift but same duration and less overlap.  The J was faster in high speed acceleration (for example 0 to 100 mph) perhaps more likely due to lighter weight than the F and especially with the use of short rams with exhaust headers (vs. long rams and log exhaust manifolds) and perhaps the slightly larger exhaust valve size and larger 2.5 in exhaust system, and certainly the solid lifter/cam setup allowed for higher rpms as well and the setup was tuned to a 3600 rpm torque peak with the short rams  vs. 2800 rpm for long rams.   The F Special (400 hp solid cam) was clearly more aggressive (ie. tuned for high rpm power and less low end torque) than the J/ram K cam.   The F Special was intended for high speed racing, not regular road use; whereas the J is perfectly suitable for the road.

 

Carl Bilter

Cub J consultant

 

 

From: John Grady <mailto:jkg@xxxxxxxxxxxxxxxxx>  

Sent: Monday, January 06, 2014 10:05 AM

To: Chrysler300@xxxxxxxxxxxxxxx 

Cc: 'Jean-Yves' <mailto:jymopar@xxxxxxxxxxxxxxx>  

Subject: [Chrysler300] Cam specs different years.

 

  

I have run into some issues trying to identify 300 C or D cam specs, I have 2 what are claimed to be 300D cams, but have no ID beyond 3 numbers stamped poorly,  near gear , in rough part of cam casting..sound right? Any one have a C or D cam they know is real , with description? I do not have those stamped numbers handy.

This brings up looking in aftermarket; only 392 “in production” “listings” seem to be Comp Thumper series, but those are hydraulic for 392. In looking more, hot heads has a 280 cam , solid and hydraulic, from which info I ordered a hydraulic for a non 300 392, and it turns out to be an Isky cam; Might be too much for a letter car. One person in their parts lists  had a 270 Isky mega cam, both seem in right area, but was unsure what original MOPAR duration was.(for 375/380 HP cam) ; I did buy that 270 cam, price was right . That started me thinking about hi po hemi cam specs ,355 hp 354 and 390 HP 392. How hot did Chrysler go on cams?  Having been young once , I also made the mistake of overcamming. Much over 280 is asking for it , especially with old Torque flight converter. (stall when you push D) 

Without taking sides, a modern hydraulic is probably better than a 50’s solid; for one thing you should pick up lift due to lack of running gap, for same lift spec, and under 6K modern hydraulics do not cause problems ; and adjustment of solids, esp with adj pushrods, goes away, along with a big oil soaked messy hassle.....in going through all this also found out solid lifter push rods for  C D ,probably all solid A block hemi, have 3/8 balls on both ends, hydraulics 5/16 ; on my supposedly “D” engine someone used 5/16 push rods, 5/16 hydraulic lifters  with D rockers and supposedly D cam, all wrong . But Hot Heads makes 3/8 by 5/16 pushrods ( might be adjustable but lock them) so you could run hydraulic cam and lifters with D adjustable rockers , using Chevy approach of one turn tight beyond clearance click. But that means set up hot and oily. Not good.

This brings up more generally ram cam specs , long ram, and J cam specs. I had a J , much more cam in it than F , or so it seemed ; ----and what was in 400 HP F?-

While a lot to ask, it strikes me someone in club has all this at finger tips , maybe a list? Note also that difference in duration between advertised lift and lift at .050 duration in this range is about 50 degrees ; so a 280 is about 230 at .05. 

Comments welcome ; it would be good for all of us to know this data; and then comes how to tell what cam is what. .

Also does anyone know a simple way to tell hydraulic from solid grinds? I know it can be done at cam manufacturer by some kind of cam plotter they have , which would show accell ramps on solids before main lift event . Maybe dial indicator on lifter in partially assembled engine, and plot it ? This problem will get worse, due to parts hoards with no real history, and now they are very old piles indeed.

Thank you,--as I say comments welcome.

John Grady





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