[Murf]

Hi, would anyone have or remember the specs on this cam Ken Keffer used to sell a lot? I have one in the wife’s car & have misplaced the cam card.
IIRC, 230/236 on 110 LSA but that’s all I remember or misremember. I don’t remember the lift or what the ICL was supposed to be.

I have this in the wife’s convertible and have had little luck trying to get rid of a stinky idle problem.
It sounds real good but pretty gassy smelling. I’ve fiddled with ignition & carburetor with out much success. The winter I thought I would check to see if it was installed correctly or maybe replace with something with a wider LSA.

Thanks !
Murf

[77 TRASHCAN]

I think David Jones has one in his GTO, maybe he will post, if he's feeling OK, he's had health issues lately...

What carb do you have?

[Murf]

Thanks Stuart!


Sent from my iPhone using Tapatalk Pro

[Murf]

Originally Posted by 77 TRASHCAN

I think David Jones has one in his GTO, maybe he will post, if he's feeling OK, he's had health issues lately...

What carb do you have?

I’ve had a Holley on a RPM, a ThermoQuad on a RPM, a Quadrajet on a RPM and now have a Quadrajet built for me by those guys in Texas on a stock manifold. I’ve messed with the timing till I’m blue in the face. It runs great but has a stinky idle.

Murf


Sent from my iPhone using Tapatalk Pro

[pastry_chef]

I've never seen a cam card for Jim's first cam.
I believe the lobes are intake 3315, exhaust 3316 - 110 LSA.

What is your exhaust system like?
Depending on combo I'd also suspect it may not be degreed correctly.

A tuned 455 with headers and good exhaust will not have 'stinky exhaust' running even slightly larger hyd roller 236 / 242 on 110 LSA - IC 106. It also gets fantastic mileage (around 20 MPG) cruising with overdrive on the highway.

[Murf]

Originally Posted by pastry_chef

I've never seen a cam card for Jim's first cam.
I believe the lobes are intake 3315, exhaust 3316 - 110 LSA.

What is your exhaust system like?
Depending on combo I'd also suspect it may not be degreed correctly.

A tuned 455 with headers and good exhaust will not have 'stinky exhaust' running even slightly larger hyd roller 236 / 242 on 110 LSA - IC 106. It also gets fantastic mileage (around 20 MPG) cruising with overdrive on the highway.

Thanks for the reply PC!

Exhaust is Oversized Ram Air manifolds with 3 inch to a Torque Tech X pipe, 2.5 out to long case Dynomax mufflers & 2.5 tailpipes.

I have 20 degrees in the dist & have tried 10-18 initial with ported & unported vacuum advance. Idle at @900 and IIRK high single digit vacuum reading at that idle speed.

Thanks for your input!
Murf


Sent from my iPhone using Tapatalk Pro

[ponjohn]

I " believe" it is similar to the stump puller.

[Mike Davis]

Make sure you have a full 12v to the coil. I had this problem on my Dad's 67. Had a heavy exhaust smell at idle and low rpm cruise. When I put it together it still had the resistor wire and I forgot to change it. Found out it only had 9volts at coil. Changed the wire and it cleaned the smell up.

[grandam1979]

Found this,

[Cliff R]

Do you have full control with the mixture screws from rich to lean?

This means that if you turn them it you reach a point where the engine RPM's fall off and idle quality gets worse, then you can back them out and establish good idle, then come out further and make it rich to a point where it starts to load up some.

With LSA, all else being equal the cam will have more overlap and both intake and exhaust open for a longer period of time as the engine rotates. This does several things, including bleeding off some cylinder pressure and allowing some unburned intake charge to get pulled into the exhaust. When overlap is great enough the engine responds by developing a miss or rough idle and the sound folks love to hear.

Unfortunately the byproduct of the great sound can make things a little stinky out the back. To offset the poorer efficiency at idle we can increase timing and add more fuel. Yes, add more fuel. I know this sounds backwards but when combustion efficiency is lowered we need to lead the timing a bit more and add more fuel. This helps get a cleaner burn than not putting enough fuel in or not adding enough timing.

Each engine has both a sweet-spot and limits as to how much we can add in both areas, but I've always been able to custom tune just about any "reasonable" engine combination for pretty clean exhaust and strong/stable idle quality in and out of gear regardless of how big the cam was, how poorly chosen or how tight the LSA.

Even with all that said each combination is a little different and despite the very best efforts you still may have to deal with a little stink out the pipes if you want to have idle quality with a bit of "attitude" to it.

Something else I'll add in is that compression for sure is your friend with this sort of thing. The worst combo's to tune for stink out the back will be lower compression engines with tight LSA or relatively "hefty" cams in them. It's just the physics of things and not much can be done about it if you don't have reasonable compression based on CID and the cam choice.

Something else I'll mention is vacuum. If you aren't seeing at least 12" vacuum at idle speed without having to run the timing clear off the scale the cam choice isn't optimal for what you are doing. Doesn't mean it woln't work or you can't get away with it, just means that the engine isn't obviously happy with it.

For well thought out engine combo's I like to see 12-14" vacuum at idle with around 10-14 degrees initial timing. This is down around 700-800rpm's, not up at 900-1000rpm's. If you find yourself having to idle one that high it will more likely than not have other issues like hitting the trans pretty hard when placed in gear, too much RPM drop when placed in gear, or "run-on" when the engine is shut down hot and well heat soaked.......Cliff

[Cliff R]

I use this cam in "mild" 455 engine builds. It's a home-run because it doesn't require "battleship" valve springs and a ton of running-room under the retainers.

In a 455 with around 8.8 to 9 to 1 compression idle quality is dead smooth clear down to about 600rpm's where you can just start to hear a little "attitude" in the exhaust. It makes around 14-16" vacuum at 700-750rpm's and clean exhaust.

It is the smallest cam I'd ever use in a 455 built here even low compression builds.......

[77 TRASHCAN]

Murf,
Do you have a carb number???

[Murf]

Mike, I’ll check that. I did use a M&H replacement harness with HEI connection built and n. I will check it out though. It runs out fine too, is that how yours acted?

Cliff, If I have the cam that gandam1979 posted, which I think I do would it act like what I’m experiencing without being installed wrong?It doesn’t seem like the valve events are way off when comparing the two but I do not know what I talking about really. . It’s a .060 over 455, zero decked with 6x4’s on it. I’d think slightly over 9.0 to 1

I don’t as you say, have control of the idle mixture. They mixture screws have had very little effect on idle quality on any of the carbs I have had on it.
On the one that’s on it now, I can bottom them out or be at 2 turns out with very little difference. That & low vacuum at idle got me thinking there must be something else going on.

Jeff, don’t know the carb # of the top of my head but I’m beginning to think I may have something else going on.

Thanks again everyone!
Murf



Sent from my iPhone using Tapatalk Pro

[Scott65]

I'll offer a suggestion for after you get everything optimized. Add an oil separator inline in the pcv system. My cam has tons of overlap (106 lsa installed at 102, 248/254 duration @ .050) and I'm light on compression for the application, so I had a good bit of exhaust smell for a long time. Adding the oil separator and pulling through a big K&N valve cover breather made an amazing difference. Not sure if its universal, but those were my results.

[77 TRASHCAN]

I thought having the carb number might help Cliff, help you!!!

[Steve C.]

To add to the confusion I went back and looked at my old notes for Ken's "butcher Special" hydraulic roller cam.

Comp XE lobes 3315B & 3316B

Back then ordered with the "B" suffic codes it was 281/287 at .006" tappet lift. And typically ordered with a 110 LSA.


.

[grandam1979]

Originally Posted by Steve C.

To add to the confusion I went back and looked at my old notes for Ken's "butcher Special" hydraulic roller cam.

Comp XE lobes 3315B & 3316B

Back then ordered with the "B" suffic codes it was 281/287 at .006" tappet lift. And typically ordered with a 110 LSA.


.

Should be no confusion I posted the cam card.

[Steve C.]

Thank you. I spaced that.


.

[Gator67]

Originally Posted by Cliff R

I use this cam in "mild" 455 engine builds. It's a home-run because it doesn't require "battleship" valve springs and a ton of running-room under the retainers.

In a 455 with around 8.8 to 9 to 1 compression idle quality is dead smooth clear down to about 600rpm's where you can just start to hear a little "attitude" in the exhaust. It makes around 14-16" vacuum at 700-750rpm's and clean exhaust.

It is the smallest cam I'd ever use in a 455 built here even low compression builds.......

Exact same cam I got from Kens for my 9.5 to 1 462. It is very smooth. Sometimes I wish I would have gone a little bigger.

[Cliff R]

As mentioned it is the smallest cam I'd even consider using in a 455 build even low compression engines. Even so I see folks using smaller cams in 455's on tighter LSA's then wondering where all the power is at?

Here is a dyno chart from a 455 Super Duty engine with that cam in it, and it has high ratio rockers on it. Notice it's done just past 5000rpm's......

NOT having control with the mixture screws usually means that you are pulling some fuel from the main system (nozzle drip). Take a look in the carb at idle speed and see if any fuel is flowing from the boosters. If not it may simply need more bypass air as there is too much transfer slot exposed.

Next time it fully warmed up at idle speed gently "tip-in" the choke flap or use your hand to cover part of the choke housing to fatten it up some. If it smooths out and idles better it's just too lean or not enough fuel at the mixture screws........Cliff