Slant six builders...Lets talk Cams

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Princess Valiant

Princess Valiant

A.K.A. Rainy Day Auto
Joined
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I am rebuilding my slant ....its a 1970 Slant six.

I want a new cam and lifter set but I do not understand cam numbers so good so what do you guys out there run and what is a good one to get.

the engine .....1970 slant six with a shaved .070 head and a decked block, bored .030 over and has a Clifford intake and header (4bbl.)

Transmission is a 4 speed from a 65 Barracuda

The car is a 1963 Plymouth valiant wagon and I plan to use some low gears ....either 3.55 or 3.91. Definitely not a race car, will be used on the streets, possibly tow a small pop up trailer and,/or a lawn mower trailer.

I don't care gas mileage and the 4 speed says the idle can be rough if need be, No power brakes or any kind of vacuum accessories at all

what is a good cam and where can I order one today .....GO!!! :)

I had suggestions before but nothing I could real world find and order today.

other question is if the head has been milled and block decked and all that good stuff, will I need custom pushrods or is there enough adjustment in the stock pushrods and rocker arms ??

I need new pushrods because I do not currently have any.....so any help on where to order today ....GO!!! :)
 
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When i had my ex's slant built for her Dart, I called Dave Crower at Crower Cams and he came up with a custom grind for her car at 260° duration and .495" lift... She is happy with it...

Dave Crower has since passed, but Crower Cams is still going... I would call them and see what kind of grind they would recommend for you...
 
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i would go over to slant6.org - as indicative of the site name, those guys and gals over there live and breathe slants. I've found a guy going by DusterIdiot to be most helpful as he knows his stuff.

As to your build, how much has the blocked been decked? Based on all your measurements, what is your expected compression/dynamic compression ratio? That will play a big part on cam specs. As to buying a cam/lifters, why not send your cam to Oregon Cam; they will re grind your seasoned cam to any of their listed or custom grinds. They can also reface your lifters or new are available. Unless your block is really decked a lot (100 thou or more) and in conjunction with your head cut, stock pushrods should work just fine.

I am building a pretty stout hydraulic lifter motor as I pretty much had everything to give it a try and it will be a bit different.
 
Rainy Day Auto said:
other question is if the head has been milled and block decked and all that good stuff, will I need custom pushrods or is there enough adjustment in the stock pushrods and rocker arms ??

I need new pushrods because I do not currently have any.....so any help on where to order today ....GO!!! :)
Click to expand...

Smith Bros. made a set of custom length chromoly pushrods for my 340. Top notch pushrods and the person I talked to was pretty knowledgeable. If you don't know what length you need the best thing to do is to get an adjustable pushrod and measure for the correct length. Valvetrain geometry isn't something you want to mess up.
 
You can take an easy .100 from the head/deck and keep the stock pushrods.
Cam? KEEP IT SMALL!
The Slant is handicapped from birth with too small a bore, (for the stroke) and too long a rod.
Result..below 3000 rpm or so, it will be a dead suck pig no matter what you do.
Look at the Comp Cams RV grind they have listed on Summit.
 
whitepunkonnitro said:
You can take an easy .100 from the head/deck and keep the stock pushrods.
Cam? KEEP IT SMALL!
The Slant is handicapped from birth with too small a bore, (for the stroke) and too long a rod.
Result..below 3000 rpm or so, it will be a dead suck pig no matter what you do.
Look at the Comp Cams RV grind they have listed on Summit.
Click to expand...


Even the 225???

Don't all slants have the same stroke, but different bore???

So the 225 should have the better bore/stroke ratio than the rest.... Or is it still too far off???
 
I remember there was an Erson grind that either Frank or Dutra or both got with Erson on to custom grind. That cam is still available today......I don't remember the grind, maybe @slantsixdan will chime in here.........but the cam was a "reverse grind". Meaning it has more duration on the intake side than the exhaust. They found it worked rather well with the slant six head. It was a mild grind, but did have some rumpity sound to it. I think you would like it.

It suddenly came to me......it's called the reverse grind 270. That's the one.
 
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X1 on Oregon Cam Grinding, as well as checking out slantsix.org. I've gained a ton of info and help from that site as I work through my build. I am assembling a 79 slant to replace my original motor in my 66 Valiant, and it sounds like your goals are similar to mine. I wanted something streetable but healthy, with decent mileage and running well on junk gas. I decided to set it up for torque as opposed to horsepower. Slants have a bigger problem with good intake flow than exhaust, so my cam is set up accordingly. I had a mild clean-up port job done on the head, had bigger valves installed, and shaved it enough to get the static compression up to about 9.2 which got me dynamic compression of 8.1. It's getting an Offy 4-BBL intake with an Edelbrock 500, and dual Dutra duals for the exhaust. The cam was custom ordered from OCG on the recommendation of one of the slant gurus. It's a 1416 grind on the intake, and 819 on the exhaust with 108 degree lobe centers and installed at 103 degrees or so. Total duration is .258/.248 (226/219 at .050 lift), and overall lift is .459/.437. Projected results of all this should put me at about 170 HP and about 230 foot pounds of torque.

Hope all this helps. If you decide to use OCG make sure you talk to Ken to set up your order. They do great work, turnaround time was quick at about a week, and the price was right - only about $80 or so if I recall.
 
krazykuda said:
Even the 225???

Don't all slants have the same stroke, but different bore???

So the 225 should have the better bore/stroke ratio than the rest.... Or is it still too far off???
Click to expand...
Yes, they all have the same bore but the geometry SUCKS on all but the 170.
The bore being too small for the stroke, essentially means that the power pulse will not have enough oompf to work the crank with any sort of anger.
Add the long rod into the equation, and the power pulse is being used up too soon in terms of crankshaft degrees to generate any effective torque.
Also, the lack of angularity with the long rod means that power pulse is being used up during the least effective phase of the rotational cycle.
Things don't really come into sync with the 225 until around 3500 rpm
 
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The judgement of the design depends on a number of factors and the purpose of the engine.... Design for production and fitting into a small car's engine compartment and grocery getting and powering a forklight will give a different design result than designing for minimum times on a 1/4. Block length had to be limited for the new new generation of compact cars (Lancer/ Valiant for the Chrysler stable), and that would force smaller bore size for an inline 6 and that would push the stroke up to get the cubes, which in turn would push the rod length to avoid TOO much rod angle with the small bore. (No sense in adding the cost of notching the bores for a production engine, right?) And small rod angles lower piston and bore wear.... important for production engines. So viewed in that way, it does all work well together. It just ain't a race engine design!
 
nm9stheham said:
The judgement of the design depends on a number of factors and the purpose of the engine.... Design for production and fitting into a small car's engine compartment and grocery getting and powering a forklight will give a different design result than designing for minimum times on a 1/4. Block length had to be limited for the new new generation of compact cars (Lancer/ Valiant for the Chrysler stable), and that would force smaller bore size for an inline 6 and that would push the stroke up to get the cubes, which in turn would push the rod length to avoid TOO much rod angle with the small bore. (No sense in adding the cost of notching the bores for a production engine, right?) And small rod angles lower piston and bore wear.... important for production engines. So viewed in that way, it does all work well together. It just ain't a race engine design!
Click to expand...
She wanted a cam recommendation.. I gave one and the reason why
 
I emailed Ken at Oregon Cams with my rebuilt 225 specs AND intended purpose and he recommended 2 grinds. I went with the milder one as mine is intended as a driver to go anywhere in the country. Buying a cam to get that hot car sound is kids stuff when the car sees 99.9% street use.

IIRC, I think it's 252 duration and about .43-.44 lift. Not much except when you consider my 1964 had a stock valve lift of .375. Rebuilt head, pocket ported, gasket matched and cut .080

You have a wagon with 170 cubes, a 3.09 first gear tranny and 3.55 or 3.91 gears. I have a 3.09 trans with a 3.23 rear and wish I had OD. I'm always ready to shift up to the next gear but it ain't there.
 
whitepunkonnitro said:
Yes, they all have the same bore but the geometry SUCKS on all but the 170.
The bore being too small for the stroke, essentially means that the power pulse will not have enough oompf to work the crank with any sort of anger.
Add the long rod into the equation, and the power pulse is being used up too soon in terms of crankshaft degrees to generate any effective torque.
Also, the lack of angularity with the long rod means that power pulse is being used up during the least effective phase of the rotational cycle.
Things don't really come into sync with the 225 until around 3500 rpm
Click to expand...

Ok, I had it backwards, same bore different stroke....
 
I am so sorry i seem to have confused some. My engine is a 1970 225.

I think my car originally had a 170 but that is long gone so i have a 225 out of a 70 challenger.
 
So far, i am finding comp cams to be the most available.

Everyone else either needs a phone call like it's 1980 for a custom thingy.

Comp cams is on summit and ready to ship today
 
Rainy Day Auto said:
So far, i am finding comp cams to be the most available.

Everyone else either needs a phone call like it's 1980 for a custom thingy.

Comp cams is on summit and ready to ship today
Click to expand...

But the off the shelf grinds won't be as suited for your combo as a custom grind will be...
 
The car is a 1963 Plymouth valiant wagon and I plan to use some low gears ....either 3.55 or 3.91. Definitely not a race car, will be used on the streets, possibly tow a small pop up trailer and,/or a lawn mower trailer.

I don't care gas mileage and the 4 speed says the idle can be rough if need be, No power brakes or any kind of vacuum accessories at all
Click to expand...

whitepunkonnitro said:
You can take an easy .100 from the head/deck and keep the stock pushrods.
Cam? KEEP IT SMALL!
The Slant is handicapped from birth with too small a bore, (for the stroke) and too long a rod.
Result..below 3000 rpm or so, it will be a dead suck pig no matter what you do.
Look at the Comp Cams RV grind they have listed on Summit.
Click to expand...

halfafish said:
X1 on Oregon Cam Grinding, as well as checking out slantsix.org. I've gained a ton of info and help from that site as I work through my build. I am assembling a 79 slant to replace my original motor in my 66 Valiant, and it sounds like your goals are similar to mine. I wanted something streetable but healthy, with decent mileage and running well on junk gas. I decided to set it up for torque as opposed to horsepower. Slants have a bigger problem with good intake flow than exhaust, so my cam is set up accordingly. I had a mild clean-up port job done on the head, had bigger valves installed, and shaved it enough to get the static compression up to about 9.2 which got me dynamic compression of 8.1. It's getting an Offy 4-BBL intake with an Edelbrock 500, and dual Dutra duals for the exhaust. The cam was custom ordered from OCG on the recommendation of one of the slant gurus. It's a 1416 grind on the intake, and 819 on the exhaust with 108 degree lobe centers and installed at 103 degrees or so. Total duration is .258/.248 (226/219 at .050 lift), and overall lift is .459/.437. Projected results of all this should put me at about 170 HP and about 230 foot pounds of torque.

Hope all this helps. If you decide to use OCG make sure you talk to Ken to set up your order. They do great work, turnaround time was quick at about a week, and the price was right - only about $80 or so if I recall.
Click to expand...

KosmicKuda said:
I emailed Ken at Oregon Cams with my rebuilt 225 specs AND intended purpose and he recommended 2 grinds. I went with the milder one as mine is intended as a driver to go anywhere in the country. Buying a cam to get that hot car sound is kids stuff when the car sees 99.9% street use.

IIRC, I think it's 252 duration and about .43-.44 lift. Not much except when you consider my 1964 had a stock valve lift of .375. Rebuilt head, pocket ported, gasket matched and cut .080

You have a wagon with 170 cubes, a 3.09 first gear tranny and 3.55 or 3.91 gears. I have a 3.09 trans with a 3.23 rear and wish I had OD. I'm always ready to shift up to the next gear but it ain't there.
Click to expand...


With the 3.09low, and performance gears(3.91 is almost too much)(and 3.55 probably just right), and about 26" tall tires, and 4 gears, You can go pretty big on the cam. Because the splits (excluding the 1-2) are pretty tight, I personally would pick a tight LSA like 108. With a 10.97 starter gear launching you pretty nice with a lightweight A,Getting to 20mph/3000rpm will be the key.From there on up, you will be all right. So, that means a bit of clutch slippage will be all you need.3.55s will get you 55mph@5000 rpm in second gear
So if the shift rpm was to be 5000, then the power peak might be 4600. I don't know what durations that might be for a slanty, but for a 360 that would be pretty small, maybe a 250ish. I imagine for a 225, you might want 260 ish
 
Hey guys sorry to barge in on this thread but I wanted some ideas, Rainy Day Auto I have bought the comp cams kit and the install was straight forward, that being said... I have the comp cams kit, offenhauser intake, holley 4160 390 cfm, and hooker long tube headers. I have gotten the car to hold an idle now after playing with the timing (I had to jump a tooth on the dizzy) the car will idle at 1000 but will climb up to 1300 and with the hood closed it dies and when a gust of wind blows by (the beautiful San Diego breeze) RPM's will climb. When the accelerator pedal is barely tapped RPM's will climb to 3000. Nothing major done to engine, head cleaned up all valve guides done. Seems like a vacuum issue to me but no leaks. Any ideas as to what may be happening?
 
Rainy Day Auto said:
So far, i am finding comp cams to be the most available.

Everyone else either needs a phone call like it's 1980 for a custom thingy.

Comp cams is on summit and ready to ship today
Click to expand...
Mmmmmm.... hold just a moment. one of the things to consider is the oil pump gear. It is driven directly off of a mating gear on the camshaft; this gear is a weak point in the system, known to fail from time to time, and some cams have been known to be hard on the pump gear. If it goes, then there goes your oil pressure, and there goes your engine unless you catch it immediately.

IIRC, Comp is one of the cams that may have been problematic in this regard; maybe someone else can confirm/deny this; or go onto slantsix.org to read up more on this. Again, just IIRC, it is in the cam blanks used. It seems like Oregon has the 'formula' for this aspect of the /6 cams.

This article discusses the oil pump gear work by Doug Dutra in detail, and mentions the cam gear in the latter half of the article.
Title
 
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SunfireYellow said:
Hey guys sorry to barge in on this thread but I wanted some ideas, Rainy Day Auto I have bought the comp cams kit and the install was straight forward, that being said... I have the comp cams kit, offenhauser intake, holley 4160 390 cfm, and hooker long tube headers. I have gotten the car to hold an idle now after playing with the timing (I had to jump a tooth on the dizzy) the car will idle at 1000 but will climb up to 1300 and with the hood closed it dies and when a gust of wind blows by (the beautiful San Diego breeze) RPM's will climb. When the accelerator pedal is barely tapped RPM's will climb to 3000. Nothing major done to engine, head cleaned up all valve guides done. Seems like a vacuum issue to me but no leaks. Any ideas as to what may be happening?
Click to expand...
Yeah, so, starting a new thread will be a good idea cuz both yours and the OPS could be a long story
 
I think the cam gear issue has passed. "....A Slant 6 with a stock pump running 30W oil and 45 pounds of pressure will run forever at normal driving speeds. But a racing engine with a high-volume pump, 50W oil and 65 pounds of pressure really loads that little gear at 6000 rpm!..." None of these 3 killers are needed on a street slant.
 
Rainy Day Auto said:
So far, i am finding comp cams to be the most available.

Everyone else either needs a phone call like it's 1980 for a custom thingy.

Comp cams is on summit and ready to ship today
Click to expand...
Comp Cam nitride harden the cams which is much harder than the oil pump gears.It will eat your oil pump gear till you lose oil pressure,then all your works is for nothing...

nm9stheham said:
Mmmmmm.... hold just a moment. one of the things to consider is the oil pump gear. It is driven directly off of a mating gear on the camshaft; this gear is a weak point in the system, known to fail from time to time, and some cams have been known to be hard on the pump gear. If it goes, then there goes your oil pressure, and there goes your engine unless you catch it immediately.

IIRC, Comp is one of the cams that may have been problematic in this regard; maybe someone else can confirm/deny this; or go onto slantsix.org to read up more on this. Again, just IIRC, it is in the cam blanks used. It seems like Oregon has the 'formula' for this aspect of the /6 cams.

This article discusses the oil pump gear work by Doug Dutra in detail, and mentions the cam gear in the latter half of the article.
Title
Click to expand...
Good advice !!!
 
Rani,I bought a Oregon regrind from RRR a few years back when he gave up on his 63 Dart build....he was going to run a four speed and 3.91 gears,it maybe to radical for your application but I got it at my shop and will give the specs tomorrow. ..
Working tomorrow on my 360 build behind close doors.
Just rembered RRR had a well ported head,the cam probably too much for your use.
 
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