Ed:
Been known to do that at least once…

Generally I don’t wind her up in town though, way, way too noisy. It scares women & little children, and attracts the newly appointed noise cops in Bangor hell bent on muffling all Harley’s within a hundred miles… The Bastards.

CJ:
So what is the displacement of your stroker? And, how much larger are the Ford valves than Engbld valves, I can’t remember. Also what is the welded up crank modification?

Bill

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Rick:
The Dart sometimes feels faster particularly after driving my wife’s 3.7 L 4x4 Nitro, however after running my bone stock 300 C (14.5s @ 98mph) for a day, the Dart feels like a there is a bucket tied to its rudder getting off the line, and leisurely out on the road… I guess it is all relative.

Perhaps this proposed cam change may remedy the sluggish take off feel, and perk up highway performance a bit… I do hope.

Rick you are correct, as the slant six Dart came from the factory, there has been a big improvement in her performance, and its handling is much tighter with the HD suspension I installed a few years ago. I guess I forget this is a 44 year old car trying to keep up with today’s average automotive fare; which if these new cars could have been on the road in 1967 would have been considered almost super cars.

Just think, a fast VW in 67. LOL…

Oh yeah, almost forgot # 53, Herbie.

I take it all back.

Bill

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

CJ:
I can’t pull that much vacuum rolling down a hill of 12% grade in second gear. LOL
I’m glad to see you are trying your best to reduce the gasoline glut we have in this country. There are stations on every corner trying to get rid of the stuff, and not making much progress at it... LOL


Did you say you’re running a EDB/Carter 500 AFB? Dose that carburetor have vacuum secondary’s?

Bill

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

The carter/edelbrock has an air valve. The secondary butterflies are mechanical, the air valve has a weight on the AFB, or an adjustable spring on the AVS. They both work on flow. When flow is high enough, the pressure differential opens the secondary air valve, which looks like a second set of butterflies.

The primary uses metering rods in the primary jets, the secondary uses jets without metering rods, much like a Holley does.

If you visit the Edelbrock site you will find a technical section where you can look over PDF files. Pictures help!
They also cover all the tuning stuff for these carbs. I will hazard a guess that for a street/strip build, like mine, you will land pretty durn close to base jetting and metering rods. That's what I'm running with only a change to the pump shot.

CJ

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Part of Tyrde-Browne Racing

Oh! By the way,
Thank Fopar for converting me to Carter.

My car would likely pull down 2/10ths running a 500 CFM Holley two barrel. Trouble is, I wouldn't be able to run on the street without the dreaded dead spot. No matter what I did, I could move it, but couldn't get rid of it!

But OMG! The 500 Holley with a 50cc pump shot left like nothing else! As long as I kept it wide open, it went like a skalded cat.

I didn't play with the 500 long enough to figure things out. My engine is too fresh to wash the cylinders with gas. For a drag only car though, Wahoo!

CJ

PS: 250 cubic inches

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Part of Tyrde-Browne Racing

Oops.

I can't hold the rear on the ground with street tires let down to 18# anymore.

I run 15.0 passes on drag slicks.

I run in the 15.30-15.50's on street tires. They howl and complain 'till I'm well past the tree, despite my locker.

CJ

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Part of Tyrde-Browne Racing

State of build + and my expectations, never seem to ever meet on the same page;

CJ: What are you running for rear gears? I may have asked this before, but what compression ratio are you at?

15.5 seconds for my car would shave off about one second from present tune. I would love to have a problem with hooking up on take off, something that is not a problem unless road is wet.

You’re about 20 cid larger than my build, or I’m 92% of yours. I’m not clear as to how much difference in performance that 8% difference of displacement makes, how much the cam, carb, and other factors contribute to total performance between both our builds… As things stand presently, your car would eat mine for lunch.

From on line calculators, that 390 Holley I have is close to ideal for my build, but who knows for sure without flow testing… You are running a 500 cfm which I should think your engine can’t quite max out, but your engine’s requirements’ could possibly exceed 390 cfm. I’m fully aware of how hard it is to tune a Holley for street & strip, and that Eddelbrock you are using is looking real nice from here.

Is there a sweet spot percentage where the engine’s need for air, and a carburetor’s rating in relation to the need? In other words, is best power combination say 80%, or 90%, or X% of carburetor flow rate?

Bill

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Volaredon: You need bigger paper…

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Hey Bill!

OK. 3.50 gears. Ford 8", Richmond Gear Locker.

The big difference is I come on at much lower RPM, and fade out much more quickly. This thing makes power on the bottom. I had 11:1 compression since I didn't know how badly the machinist screwed up my crank throws. They were supposed to be 4.440" Actual measurement came out at 4.475" of stroke. I could get a .010" feeler gauge between the big end to the rod and the block. Not a .011"

My engine will make gobs of torque suddenly off the bottom. I also run 198 rods at 7.005"

We may be talking Apples and Orangutans here.

The nice thing about the Edelbrock/Carter is that it is a flow operated secondary. It flows only what one needs.
If the Carter 400 AFB has a smaller primary, but the same secondary as the 500, it likely would work even better. I haven't found one. With the same size primary, it won't work any differently.
The 600 AFB uses a bigger primary venturi, and the same secondary as the 500 AFB. Excuse me. The restriction caused by the annular booster on the 500 is greater than that of the 600. See what I mean? I picked up a couple tenths changing from the 600 annular boosters to 500 CFM boosters and running the jetting that matched the base jetting per the Edelbrock tables. After playing with things extensively, the base jetting was where I re-landed.

A 390 Holley is about perfect. A 225 Slant six hits at 375 CFM if you work up the numbers. A 500 AFB will perform very similarly, but with my build, I run out of air with the 390 Vac Secondary. I don't run out of air with the 500 Carter. My engine likes the air valve. I haven't mounted up my 390 Double pumper which may solve this problem. Perhaps later.

My big valves, and all the port work, intake work, and so forth....

Yep,.. it's an Orangutan.

CJ

Edit: PS- your going to need to tack on the true 2500 rpm stall converter I carry. For my build it's ideal. Any more and I'd likely torch the slicks.

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Part of Tyrde-Browne Racing

Good discussions here... I agree with comments on Holley 500 2bbl probably being faster than Edel 500 4bbl, but drivability and economy better w/Edel.

CJ, I'm knockin' on your street/strip door - Slantkota went 15.39 this weekend! I smell 14s next year. Battle of the stroked pigs...

Lou

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Home of Slant6-powered fun machines since 1988

CJ,

Looks as if we are running similar drive train, my stall is a bit lower, and my tire size: D205/70R14.

Is the car we are discussing a street machine, or track mobile? Dose 11.1 compression allow pump gas? I suspect that with your high compression that your dynamic compression is well above Doc’s ‘street sweet spo’t of 8-8.5:1.

I’ll have yet to calculate the various volumes to use the on line compression calculator.

Doc said RV 15M RDP runs 1000 to 5000 rpm plus a wee bit more which is well with in my idea of non stressful slant rpm, both mechanical & ear, and plants my 60 mph rpm dead center of the band. Low end grunt, and reasonable rpm head room, is something I’m now looking for. Dose anyone out there have a torque curve for this camshaft profile? For that mater is there someplace one can go to see hp & torque curves of other cams in a slant?

How does this RV cam compare to the 270/280 in road manners; anyone out there that has run both cams that can clue me in on the benefits of both profiles?

Bill

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Bill,

A great question! I have been wondering the same thing.....anybody have some results they could share?

_________________
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

Sorry 'bout that. Tunnel vision sometimes!
I spaced on this thread.

With 11:1 I was able to run Premium fuel, which out here is 92 Octane. At least that's what the sticker says. Fuel quality in Oregon is notoriously poop.

Keep in mind that all in, I have less than 25° of advance. I get a nice long dwell with the piston up top with the long rods too.

After bumping down to 10.7:1 I haven't tried to run plus, which I think is 89ish here. Cat piss regular comes out at 87 if you can believe what the tractor gas salesmen are pushing.

I'm running the cam straight up, and don't push the timing much. I may play with it a bit when test n tunes start at Woodburn next year if I'm not working on the RED. If anything I'll just widen the range. Timing starts in at 1400, and is all in by 2800 rpm. I'm mechanical only. So far I've not seen any difference in economy since getting rid of the Mopar Electronic dizzy with vac advance.

With the stroke, I'm not exploring territory over 5000 rpm. I need to get some quality time in with the car to experiment with 4900 and 4800 rpm shift points. I'm clearly out of the power above 5000, but keep in mind my engine configuration.

By keeping the cam straight up, the bottom end is very good. I've still got a pretty heavy car. 60' is in the 2.2 range. When I get on the pipe, my torque can carry me off on the high end of the track unless I'm running against something that can still make power in the 6000 or 6500 range. Moving the oil down away from the crank throws has lessened my smoke problem, but not eliminated it. At high rpm, I can watch the ring flutter as smoke in the rear view mirror. The long stroke allows the rings to loose seal as the pressures go hinky.

Good word.

The cam is a very serviceable unit that allows for solid operating range power. The 280/270 is a great cam that I can't use because my rods will start scattering bits of my block somewhere above 5800 rpm.
For an engine that is built for 6000 rpm instead of 5000 rpm, it should be the ticket. If your not going to run the engine over 5000, don't look at that one. It's got too much duration to make superior torque down low where most of us run.
The RV15M RDP is a stellar cam for a stock build IMO. Just that little bit extra in the intake events. The exhaust doesn't need it.



CJ

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Part of Tyrde-Browne Racing

Sandy can comment best on the 280/270 (230/220 @ 0.050") for street manners. From other similar cams, it will also be quite docile and make good vacuum (10 in Hg at idle or more). It will not make great power above 5500 RPM. For a real world, properly set up 225, I'd say it's useable RPM range would be 2200-5500. Idle is fair/smooth. I ran a Crane 228/228 @ 0.050" cam that was quite smooth.

Lou

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Home of Slant6-powered fun machines since 1988