Slant six builders...Lets talk Cams

-
Rusty, are the B3 rocker shaft shims something unique or are they the typical .010 .020 half round shims.
Would be nice to move the shaft over as well as up.

They're custom made for each application. Mike asks for a measurement, you give him that and he makes the shims.
 
They're custom made for each application. Mike asks for a measurement, you give him that and he makes the shims.
I will do that. I have read articles about B3 and visited their web page but never purchased from them. They are certainly into rocker arm geometry.
 
I will do that. I have read articles about B3 and visited their web page but never purchased from them. They are certainly into rocker arm geometry.

He knows it forward and back, too. Mike's a good guy.
 
Halfafish, i'm very interested about that camshaft you ordered from OCG. I'm building a mild 225, 198 rods, 2.2 turbo pistons, Offy intake, Holley 390, mild porting of the head, compression in the 9's. In other words very similar to what you built. Like you, I'm building a driver but I want a bit more "go" but it still has to be streetable. Can you tell me how that cam worked out? It sounds like a good grind, given that Slants are more restricted on the intake rather than exhaust side.
I'm worried the 108 LSA might make for too rough an idle?
Any info on idle, power band, anything would be much appreciated!

Idle quality is not based on LSA. LSA and duration are intimately coupled. With a tight LSA and a long duration is what gives you poor idle with a lot of overlap. You can’t have long duration and low LSA and have low overlap. The OCG 2106 and the one discussed here along with Dutras grinds all have reasonably short durations. If you want low end torque you want low LSA and low overlap which by definition means shorter durations. I have the 2106 8.8:1, oversized valves and it pulls like a bulldozer up to 4000 then you can feel it drop off, as I designed it. Cam companies don’t really makes cams that are actually good for most builds, they make cams that have numbers that the average customer thinks will give them power. The cam I was working on with Dutra before his fire would NEVER be a commercial success because it had durations of 192 degrees with a 108 LCA, but the grocery getter on the street torque under 3000 RPM was exceptional in the model. We also modeled his failure cam grinds and the model I had said they would be dismal failures so we had confidence the model was accurate. My build feels like what the model predicted as well.
 
I asked about 318 valves and was told that they were too long. And that you still use 318 springs with reg length/6 valves.
Also my engine cleaned up at 0.020 over. And I've heard that there may be an issue running even the SI oversized ones in a bore that small.
I wasn't looking to notch the block.

Yeah, but you cannot get the correct height for the 318 springs. So you could be looking at coil bind. If you live your life by everything you hear and are "told" you sure are limiting yourself. I've DONE IT a few times. So have others and it works fine. Run what you want. I hope they have them in stock.

Heard this heard that. That's all bullshit. You don't have to notch the block. With the SI valves OR with 318 valves.
 
huh. Interesting. I actually have a set of stock 318 valves here. have to scope it out/ have read/heard many places, that the /6 actually went to stock 318 springs as std replacement..... valves and springs came from a supposed lo mile set of '302 (casting number) 318 heads from a member here (I forget who)
 
Well though I have been working on cars for a living since the late 80s most of what I have been doing is stock replacement stuff. I've rebuilt a few slants over the years, but again, stock /but machined to clean up and bring clearances back to where they should be. Done a little performance work on small blocks but even, then mostly stock.
Looking at cam charts, overlap, duration, etc makes my head spin. So on that part of this build I am leaning on others, who know and between here and the /6.org forum, the consensus is about the same for picking a cam, and what hardware to use with it.
Not trying to argue at all, RRR, but to be honest I have had more say that 318 springs are basically "std issue" replacement for /6springs, you're the 1st that I've had say different. IDK how much lift it takes to coil bind 318 springs on a /6 but this cam that I am wanting to run is right around .435 -. 440" lift. This is for a truck that will be used like one, I doubt it'll ever see 4000 rpm.
While I'm here, what would you run then, I wanna do this exactly once.
 
Last edited:
huh. Interesting. I actually have a set of stock 318 valves here. have to scope it out/ have read/heard many places, that the /6 actually went to stock 318 springs as std replacement..... valves and springs came from a supposed lo mile set of '302 (casting number) 318 heads from a member here (I forget who)

Yes, the stock 340 spring is a good all around HP replacement. But the drawback there is the stock slant six valves are a little short to take full advantage of the extra height, so you have to be careful not to run into coil bind. That's why If I am doing "much" in the way of performance, I go right to the 318 valves.

I did not on my recently assembled "for now" motor, because the head was in great condition and I was trying to avoid extra cost associated with that. I have the factory closed chamber head in the shop now getting the 318 valves put in. I can't really afford another high dollar head, so other than the heavy milling, I kept this head stock.
 
Idle quality is not based on LSA. LSA and duration are intimately coupled. With a tight LSA and a long duration is what gives you poor idle with a lot of overlap. You can’t have long duration and low LSA and have low overlap. The OCG 2106 and the one discussed here along with Dutras grinds all have reasonably short durations. If you want low end torque you want low LSA and low overlap which by definition means shorter durations. I have the 2106 8.8:1, oversized valves and it pulls like a bulldozer up to 4000 then you can feel it drop off, as I designed it. Cam companies don’t really makes cams that are actually good for most builds, they make cams that have numbers that the average customer thinks will give them power. The cam I was working on with Dutra before his fire would NEVER be a commercial success because it had durations of 192 degrees with a 108 LCA, but the grocery getter on the street torque under 3000 RPM was exceptional in the model. We also modeled his failure cam grinds and the model I had said they would be dismal failures so we had confidence the model was accurate. My build feels like what the model predicted as well.

You also have to take in to consideration the engine's stroke. The longer the stroke, the more "calming" effect there will be on a camshaft's personality. This is why the same camshaft might idle relatively choppy in a 318, but be pretty smooth in a 360. The additional stroke "eats up" some of the camshaft so to speak.
 
huh. Interesting. I actually have a set of stock 318 valves here. have to scope it out/ have read/heard many places, that the /6 actually went to stock 318 springs as std replacement..... valves and springs came from a supposed lo mile set of '302 (casting number) 318 heads from a member here (I forget who)

Also, believe it or not, I've found that on every slant six head I've had so far, the 1.550" diameter big block springs will drop right into the stock spring pockets. They're pretty generous. So if you really wanted some serious camshaft, you could get like .100 longer valves and put a real spring in there.
 
Last edited:
Here's a picture with a 1.550" diameter dual spring in the slant six's stock, unmodified spring pocket. There's actually a tic more room. Might go to 1.580 but Idon't have any of those. lol Course, to use the dual springs, you'd have to mill the inner step flat, but that's a 15 minute job with the right tool.

1.550 SPRING SLANT.jpg
 
Just for fun here is some of the study I was doing with Doug.... you can see the 192/204 cam we were going to prototype. Nice gain over his RV10 at low RPM but dies out over 3500 RPM. You can also see what long duration does to you on the street in comparison. Really cripples you where I want all the torque but you get the best high RPM horsepower. It is a balloon, you get low RPM torque or you get high RPM HP. I myself never take my cars over 3500 other then hard passing so that is where we were trying to maximize. You can see where a stock 225 would be too and why the RV10 give it such a kick. These are all 108 LCA since we wanted torque.. larger LCA brings down low end torque so we did not explore there.

Experimental Cam - 192/204 White = Torque; Dark Blue (lower) = HP
RV10 - Maroon = Torque; Purple = HP
232/244 - Pink = Torque; Yellow = HP
Stock - Cyan = Torque; Red = HP

CamRuns.jpeg
 
IDK how much lift it takes to coil bind 318 springs on a /6 but this cam that I am wanting to run is right around .435 -. 440" lift. This is for a truck that will be used like one, I doubt it'll ever see 4000 rpm.

It would be interesting to compare notes when you get done with your truck and I get done with mine. I just did a complete .030 rebuild on the bottom end. It has an OCG 2106R grind cam properly degreed in. I gave the head a home pocket porting with a set of Engine Builder valves, 1.70 intake and 1.44 exhaust. It's getting a super six setup with a Carter BBD and the exhaust outlet opened up to a tick under 2-1/4". Single 2-1/4" exhaust out the back. The head is getting shaved .060 for compression to about 8.5:1 static for about 7.5:1 dynamic. I'm keeping the 833OD trans. Like your truck, this is for dump runs, getting gravel/firewood, and hauling my trailer around so I can buy more Mopars!
 
It would be interesting to compare notes when you get done with your truck and I get done with mine. I just did a complete .030 rebuild on the bottom end. It has an OCG 2106R grind cam properly degreed in. I gave the head a home pocket porting with a set of Engine Builder valves, 1.70 intake and 1.44 exhaust. It's getting a super six setup with a Carter BBD and the exhaust outlet opened up to a tick under 2-1/4". Single 2-1/4" exhaust out the back. The head is getting shaved .060 for compression to about 8.5:1 static for about 7.5:1 dynamic. I'm keeping the 833OD trans. Like your truck, this is for dump runs, getting gravel/firewood, and hauling my trailer around so I can buy more Mopars!
That is effectively my build. You will love it in a truck. Amazing torque.
 
Just for fun here is some of the study I was doing with Doug.... you can see the 192/204 cam we were going to prototype. Nice gain over his RV10 at low RPM but dies out over 3500 RPM. You can also see what long duration does to you on the street in comparison. Really cripples you where I want all the torque but you get the best high RPM horsepower. It is a balloon, you get low RPM torque or you get high RPM HP. I myself never take my cars over 3500 other then hard passing so that is where we were trying to maximize. You can see where a stock 225 would be too and why the RV10 give it such a kick. These are all 108 LCA since we wanted torque.. larger LCA brings down low end torque so we did not explore there.

Experimental Cam - 192/204 White = Torque; Dark Blue (lower) = HP
RV10 - Maroon = Torque; Purple = HP
232/244 - Pink = Torque; Yellow = HP
Stock - Cyan = Torque; Red = HP

View attachment 1715699204

What was "the rest" of that build? Or was it just a simulation?
 
not disagreeing with what 'Jim Kueneman' has to say, just saying that everything that he says has been said before and said better by David Zizard.

It is freaky when someone takes information that is commonly available, and says it is new stuff, that's not right.
Not saying that Jim K is wrong, just saying he should give credit where credit is due.

If you don't know. google David Zizard,,, go from there.
 
not disagreeing with what 'Jim Kueneman' has to say, just saying that everything that he says has been said before and said better by David Zizard.

It is freaky when someone takes information that is commonly available, and says it is new stuff, that's not right.
Not saying that Jim K is wrong, just saying he should give credit where credit is due.

Yes most of that comes from Vizard and a few other authors, John Baechtel and Greg Banish for a complete list of credits, not sure where I said it was new. So far what they say has worked as they said it would with my engines. Also those techniques match up with algorithms in the simulation software as well. If you follow what these guys say you get the best results you can out of simulation software.
 
Last edited:
What was "the rest" of that build? Or was it just a simulation?

Doug wanted to get the most kick out of a stock 225 so stock one barrel, exhaust manifold, head and compression. All simulation, we were right on the cusp of getting a prototype. He had contacted his cam grinder and everything.
 
Doug wanted to get the most kick out of a stock 225 so stock one barrel, exhaust manifold, head and compression. All simulation, we were right on the cusp of getting a prototype. He had contacted his cam grinder and everything.

Oh, ok. So this is not taking advantage if anything like higher compression, more induction, bigger exhaust, bigger valves or porting. Gotchya.
 
Don't know if you guys know this about David Vizard....but a lot of his early racing success was with.....Chryslers! Specifically the Chrys 4 cyl Avenger in the UK. 26 wins out of 26 races in two years with a OHV engine against OHC competition.
 
Don't know if you guys know this about David Vizard....but a lot of his early racing success was with.....Chryslers! Specifically the Chrys 4 cyl Avenger in the UK. 26 wins out of 26 races in two years with a OHV engine against OHC competition.
I got to see DV live and in person at a PRI seminar two years ago. For a senior-senior, a high energy motor head. The folks running the show had to walk him off the stage or he would still be there answering questions.
He was hawking a ‘cam simulation’ program then. The seminar attendees received a locked copy of the program on an USB drive. It was all SBC so I never did much with it. Jim K are you familiar with that one?
 
Like nobody else's experience matters? Lets all bow down and kiss David Vizard's butt. You missed a spot. Good GAWD.
 
I got to see DV live and in person at a PRI seminar two years ago. For a senior-senior, a high energy motor head. The folks running the show had to walk him off the stage or he would still be there answering questions.
He was hawking a ‘cam simulation’ program then. The seminar attendees received a locked copy of the program on an USB drive. It was all SBC so I never did much with it. Jim K are you familiar with that one?

I am not, I just started doing this sort of stuff 5 years ago and before that it was high school which was a LONG time ago.
 
-
Back
Top