Doc,

I have seen the specs on the RV10 and RV15 that you have posted. Both .435 lift on the intake.
Can you share the specs on this cam?
and also the 280/270 RDP cam Mark Guzi was running?

I was curious if the RV15/295 would put out more torque than my reground Delta Cams E254 .435 lift grind.
What did you advance the cam to? You mentioned backing it off a few degrees.

I have the torque engine you helped me build a few years ago out right now and am collecting parts to up grade it for more torque. I have the engine builder valves, a stock MOPAR dual roller chain and gear set, a new heavy duty oil pump that I need to have you rework. Not sure what else I need to do for more torque....

I do want to take a few passes at the track (Puget Sound Raceways) this summer.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

To start the discussion, here are links to the design worksheets for 2 different RDP cams.
These designs are for "street performance" use, engines that need a decent idle, lower RPM power and run on pump gas... while still being able to rev-up into the RPMs.
DD

RV10/295

RV15/295

Here is a link to an older Erson product catolog. (when they were still owned by Mr Gasket)
Go to the end of the catolog (pg 95) for a list of all their lobe "masters" and some general information about cams and cam installtion.

http://www.mrgasket.com/ftp/pdf/erson.pdf

DD

Here is another link to a thread on camshaft selection for the Slant Six:

http://www.slantsix.org/forum/viewtopic.php?t=42992

As we know, "which cam" questions are pretty common to any automotive message forum, especially if it is focused on the engine and / maximizing performance.

The big problem with selecting the "right" cam is all the different engine combinations and vehicle applications we see, especially with the SL6.
It is not a simple "one size fits all" situation.

Because of this, it is important to get as much application information as possible before looking at cam choices.
It is also important to stay on (or real close to) the stated combination when the engine is assembled. If you say you will run a .040 oversize, stock stroke, 9 to 1 compression, ported big valve head engine to be used on the street... and buy a cam for that, be sure the engine ends-up that way when assembled.
This sounds obvious but it does happen... most often I "miss" on actual compression values or the: "I will add "such & such" later"... & that up-grade never happens, sticks me with a bad combo of parts.

So we did our planning and have a goal with the desired engine outcome and use. Like the examples above)
Now we need to find (pick) the "right" camshaft for it...
Why all this typing... because I need to outline why I don't usually recomend cams... I usually don't have enough good information to go on and / or don't have a lot of hands-on experience in that particular application.
DD

Erson 280/270 225+ .040 big valves 2800 lb car 5 speed/3.55 9.25CR

Grind # TQ30/20 M 109+2 degrees

clearance Valve lift Duration Gross lift Duration@.050

Intake .015 .465 280 .310 230

Exhaust .015 .465 270 .310 220


events @ .050 Intake opens 4btdc Exhaust closes 3atdc exhaust opens 37 atdc intake closes 46 Btdc 7* overlap

intake opens 29 btdc , overlap 57* , exhaust closes 28 atdc , exhaust opens 62 atdc , intake closes 71 btdc

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

Thanks Sandy......that answers part of the question.
Does it provide good low end torque right off idle?

I am looking for a comparison to my RV10M cam grind. Mine has good torque and gets my 3600 lb 74 Swinger with automatic moving....
Since the motor is out for some up grades I was wondering if a cam change is order to get more torque...? not high end rpm necessarily, just more lows up to 2500 rpm. That is my cruise rpm.

Did you have the +2 ground in or was the advance added with a cam bushing?

Thanks,

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

For your "torque" build, you may want to try the RV10/295 RDP.
This cam will be very close to the Delta E254 (/290) that you have already run in the car.
(Note: The "/290" is the actual lift at the cam so .290 x 1.5 rocker arm ratio = .435 advertised lift)

The RDP design will give you some additional flexibility when you install the cam and these small changes can help build more torque.
Here is why...
The SL6 is a 120 degree engine design which means that a cylinder fires every 120 degrees or crank rotation. (most other engines are 90 degree designs)
The SL6 is "under-square" = more stroke the bore size.

Cam settings that seem help torque are:
-Close the intake valve sooner after BDC.
-Open the exhaust valve later. (Blow-down)
-Keep the overlap event short and a little advanced over TDC. (intake opens sooner, exhaust closes sooner relative to TDC)

So if we give the exhaust lobe a little less duration and then grind the cam with wide lobe separation, (less overlap) and install (phase) this cam "straight-up", the engine "sees" all 3 of the above.

With a single pattern cam, you have more conflict with getting an earlier intake closing and a later exhaust "blowdown" event.
DD

My Valiant is just shy of 3000lbs with driver and fuel. It has a 5 speed OD and 3,55 gears, Thats 2.5 final drive in 5th....with 235/60/14 tires.

I have chev 1.72/1.50 valves and a bowl hog . The chambers are configured a lot like Mike Jeffries heads. No porting or blending was done.

I ran a BBD on a die cast super 6 manifold with a stock exhaust and a full 2.25 pipe with Turbo muffler.

I have played with advance curve and ended up very close to the stock 65 manual trans curve with less vacume advance. I forget my initial advance....prolly 8-10.

Idle and off idle torque are excellent. It reminds me of Brens motor in Lous Slantkota. It feels like a big stroker. I can let out the clutch at an idle and idle up a small hill......mash my foot to the floor and grab 2nd.

You can set a very low idle. You can drive around town in one gear.

A lot of this is due to the super vacume signal fom the stock manifolding.

I consider this the Ultimate Super 6 street setup.

My Cr was 9.25 and I would run more CR IF you have convertor and gears.

I think you could run 10:1 CR on the strip....just mebbe in town.

My setup runs out of steam pretty quick. You cant rev far past 4500- 5000 without it falling on its face from lack of manifolds/carbs.

I have an AFB 400cfm and an Offy manifold that I think would work......but my ultimate plan was a simple TBI megasquirt. I think this setup would be ideal for that.

Bottom line: tons of mild mannered torque. Great diveability with sensible setup. Poor mans stroker . It needs gears and convertor. It needs a good vacume signal. It needs a tailored advance curve. It needs some compression (9.25/9.5 for cheap fuel) .

This cam behaves somewhat better than the Comp 264s it replaced.

Ted: your car might be a bit heavy and high geared and low compressed for this cam.

D.I ....chime in

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

.............oh yeah.....the 2 degrees was ground in. I just lined up the dots........with a degree wheel.

What s your static CR Ted?

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

Sandy,

I wish I could cut and past the formula box in here......but it comes out to 9.5.

I am 3.425 (.030 over on bore)
stock 4.25 stroke
3.525 for FelPro head gasket opening
.040 for FelPro head gasket thickness
60 cc's on the 78 peanut plug head, they only skimmed it slightly
The piston .040 down in the bore, I had the block decked per Doc's suggestion instead of the head.
total displacement volume = 73.19088
Calculated Engine Compression Ratio = 9.509011

The 74 Swinger is heavy...3600 lbs with me, a full tank, a few tools and a trailer hitch from hell. It makes a great roll cage around the fuel tank. It also has protected the car very well. In 2004 I was rear ended on the freeway. I was stopped and was hit 5 times which totaled three cars behind me. Not a scratch on the Dart...... The trailer hitch ball was missing a little black paint though. The pictures I took after the accident are on the red link below.
Even though the gears are 2.76 and a 8 3/4 Sure Grip and I run P235/60 14 BF Goodrich T/A radials, it has spunk!
However, I could use more below 2500 which is where I cruise at 60 mph. My vacuum is between 15" and 21" and hangs around 18" most of the time. I would like to get that a little higher if I could at cruise. The weight makes a big difference on vacuum at cruise. With an empty tank and no tools or spare I gain a few inches of vacuum......

Exhaust is 2.25" and running a 18" long body MagnaFlow muffler and 2" tail pipe with a 22" L x 2" dia. non-packed resonator. It is stealthy quiet!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

This is how i had Erson grind my 280/270 cam...but also had to throw in the 4th directive, for Hyperpak use: 4)Keep the overlap between 52-55 degrees....

My cam is ground at 111+4...and it worked great at 10.3:1 SCR (engine is out for refurbishment at this time...)

Besides the benefit of the Hpak, I also was using a 3.55 gear (and last year a 4.56 gear...love that OD)...the torque band was fairly flat with a moderate rise in the mid range...the HP and torque under 2K rpm are slightly above stock so nothing lost down there...It never ran out of wind with the 600 cfm carb...the 390 cfm carb tended not to go to "0" at WOT (usually left the line with a 6000-6200 rpm clutch dump then wound it up to 5500 for the up-shift...wide ratio tranny...gotta find a "good clutch disk too")

Food for thought.

-D.Idiot

From: http://www.slantsix.org/forum/viewtopic.php?t=43210
Hopefully Jay will post some additional feedback on his current RDP cam. (RV15/295?)
It sounds like he just likes "more" cam in his street, but mostly "strip" car.
DD

Linking a couple of other cam threads into this one...
Some good information for hydraulic and mechanical SL6 cams, in these postings:

http://www.slantsix.org/forum/viewtopic.php?t=43301

http://www.slantsix.org/forum/viewtopic.php?t=43251