[besserspat]

You know when you take too much time to finish something you second gues yourself and start acting weird...well here I am.

A little back ground for the car...

Have a new, entirely forged stroker 461 with SD performance CNC iron heads (260 cfm)., Ported Aluminum 71 HO intake and Quadrajet, Dougs 1 3/4 headers

Transmission is Jakes TH400 with Continental 10" Jim Hand special with balloon plate ( running nitrous too) Built , 8.5 10 bolt 30 spline axles with True trac and 3.08 gears

Car is a stock looking 73 bird. thats I drive a couple times per week, the car has manual brakes so poor vacuum is not an issue)

Now , its been 2 years that I want to finish the engine but time and focus is always the issue.

Long story short, I was dead set on a Old faithful II HR cam from Dave at SD performance, and run a set of Comp Solid roller lifters ( Second generation) on it as a hybrid solid/HR set up which seemed to work well for Cliff and some other guys here.

But Im currently refreshing my 454 LS7 and putting an old Ultradyne 402A3 , its a solid flat in it last week made me think...

My question is , how much would I leave on the table , not running the SD Oldfaithful II cam and roller lifters and going to a simpler cheaper Solid flat cam?

My problem seems to lie in my gearing , 3.08 and decent solid flat cams for Pontiacs dont seem to go well together when I look at cam recommendations....

keep in mind that I spray near 200hp on top of this.

[Jay S]

What ratio rockers do you plan to run?

If your starting fresh with the roller set up I would pick a profile that works better with the solid rollers lifters than the Old faithful 2. You need the old faithful 1 (or similar) that used the old magnum HR series profiles. OF2 has more aggressive ramps, it will work as a hybrid, but the OF1 works better and is easier on parts.

You would not necessarily loose much power with a SFT against an HR profile if you have a well picked cam and rocker set up that comes close to matching the lift of the SD cam, it depends on the rockers the SD cam would have. The cam specs look a lot different though between a HR and a SFT. SFT will have more duration at .050” and less seat duration.

[Half-Inch Stud]

The 10" into a 3.08 could show some stop sign mush for a heavy car. So you won't clearly notice either cam's low end trait.

[Formulajones]

I agree with Jay, although I would take that a step further, If you're starting fresh, why do a hybrid setup, just get a solid roller stick with correct lash ramps designed to be run this way, set the lash and forget it.

It won't be nearly as critical on lash as a hybrid setup and be a lot easier on the valvetrain, especially that OFII cam with more aggressive lobes. Either way you'll still need a spring to control it. Hybrid setups really should have the hydraulic roller spring pressures increased according to the few cam manufactures that actually support doing such a thing . Just my thoughts.

Or just do a solid flat tappet. Have worked well for Pontiacs in the past for us, and I currently daily drive a solid flat tappet. Not sure why more folks don't go this route with all the gloom and doom talk these days about all the other stuff.

If you want similar performance, you just have to take the loss of duration and lift in affect when lash is figured in when the cam is chosen and spec accordingly. It's probably going to act a little more radical than a hydraulic roller setup though.

Frankly, if I were dead set on an OFII hydraulic roller camshaft, I'd just put hydraulic roller lifters on it and call it done.

[Formulajones]

Originally Posted by Half-Inch Stud

The 10" into a 3.08 could show some stop sign mush for a heavy car. So you won't clearly notice either cam's low end trait.

Yep, converter efficiency becomes another entire subject on it's own when trying to couple that with a soft gear like a 3.08

The grunt of a well built 455 will show, Nitrous will soften that even more.

[besserspat]

Originally Posted by Formulajones

Yep, converter efficiency becomes another entire subject on it's own when trying to couple that with a soft gear like a 3.08

The grunt of a well built 455 will show, Nitrous will soften that even more.

Its been a while since Ive checked the transmission , it actually may be a 13" torque converter and not a 10" but its a Continental Jim Hand special with a balloon plate for sure.

As for the cam , I already have the roller lifters ( Comp solids) Dave at SD said my heads have springs that are stiff enough and if I changed the locks I would have enough clearance for the lift of the OF II.

The Idea of a solid flat just came while I was installing and dialing the cam in my LS7, just liked the simplicity, street friendliness and no worries to fill the engine with little needle bearings once you read all the horror stories of roller lifters giving up the ghost in your engines... no composite or bronze dist gear needed etc etc...

But for my pontiac 461 the idea was to really go roller cam.... I have no problem getting a solid roller ground with the OF II specs in mind too.

Peter

[Half-Inch Stud]

Getting a build done with HR is a financial accomplishment. seems you are there. Why not.

The Solid cam can wipe a lobe at the toe like a Flat HYD. And clickety to boot.

[Formulajones]

Sounds like you're still at a point where you have options.

Honestly I don't see one as any better than another so it'll come down to what you're most comfortable with and what your budget allows.

[Jay S]

To do a long lasting high HP solid flat tappet that matches up with a roller set up for the street it isn’t exactly cheap or simple these days. It takes EDM oiling and cam nitriding, or step up too tool steel lifters. At very least you have to do the EDM face oiling on standard mechanical lifters. And right now any one of those things could be on a 6 month back order.

[Formulajones]

Originally Posted by Jay S

To do a long lasting high HP solid flat tappet that matches up with a roller set up for the street it isn’t exactly cheap or simple these days. It takes EDM oiling and cam nitriding, or step up too tool steel lifters. At very least you have to do the EDM face oiling on standard mechanical lifters. And right now any one of those things could be on a 6 month back order.

Yep, that's how I do them, but with parts availability these days ya can't be in a hurry, lol.

[Steve C.]

And don't forget for the most part you add duration when going from a hydraulic lobe to a solid lobe.


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[besserspat]

All things considered I think I will step down to a Stump Puller Cam , I will try to find one used since everything seems to be back order now.

If I cant find the cam this winter , I may either have to "settle" for a Solid flat cam. ( opinions welcome on which one to pick)

Last option will be to either leave the rebuilt 350P in it or swap a stock rebuilt W72 400 I have sitting in the corner or the shop and postpone the 461 completion to next year.

Peter

[tom s]

FYI,call Clay Smith cams.Im sure he can do one close to the RP.I just did a engine with one of his cams and my next one will also.Tom

[Formula8]

I have a OF1 and Crower Solids. I have not had any problems with either with the moderate spring pressure Dave built my heads with or the new Crower killer, wiz-bang springs everyone guilted me into pulling my heads to install. With the way I use the car now, the cam is a bit much for me and my first move is going to be to advance it a bit from the 107 originally installed, but ultimately, I think I have too much cam and will be looking to swap someone for a SP1

[besserspat]

Originally Posted by Formula8

I have a OF1 and Crower Solids. I have not had any problems with either with the moderate spring pressure Dave built my heads with or the new Crower killer, wiz-bang springs everyone guilted me into pulling my heads to install. With the way I use the car now, the cam is a bit much for me and my first move is going to be to advance it a bit from the 107 originally installed, but ultimately, I think I have too much cam and will be looking to swap someone for a SP1

What kind of pressure are you running on the seat for the OF 1, when you sa its too much cam what do you dislike about it, soft bottom ?

[Formula8]

My notes say 185 (calculated) on the seat with the 68380X2 spring: https://www.jegs.com/i/Crower/258/68380X2-1/10002/-1#. I think the springs from Dave were around 150 and were fine.

I had this same top end package on my 464 till it spun another rod bearing. I ran great and was close to perfect with all kinds of power from about 2500 through 5500+ RPM but found myself going from no traction to needing to shift in an instant. I wanted the RPM range extended out and thought that I had no use for the brutal low end.

So I milled the heads .030, added the Crower springs, built a 433 and moved everything from the 464 to the 433. Don't get me wrong, the new motor is plenty fast across a broader RPM range. I added heavier wheels, larger rear discs, wider softer compound tires, lowered the rear significantly and changed my shock settings. Between everything, the 433 in the car as it is now is probably faster on the street than the 464 was but with the fuel injection and timing control, everything is more progressive and you don't get that explosion of torque that completely blows off the tires.

My main issue at this point is that the car actually drives quite normal and as such, I find myself wanting to just cruise it normally more which then puts me in OD a lot more and that is where the problem is. In OD I am usually at 1700 RPM or so which was fine with the 464. But with this engine the OF is not happy cruising around in that area under a light load. I'm going to try advancing it and playing with the tune a bit but suspect I am just trying to put a square peg in a round hole and at some point, will need a cam more suited to the way I actually drive the car now.

[besserspat]

Thanks for the explanation, its funny how often I found myself in similar situations, where its all great to have a fast car, but its get old quick when you just want a nice friday night drive or pick up a date. When you dont want all the noise, rattle and smell...

Ill gladly take your OF cam and trade you a smaller cam return, I think I may have a RV Flat tappet cam in a box somewhere ;-)

[Formulajones]

You can tune a lot of that out and with the EFI and timing control it's much easier to get it there.

You'll likely need more timing than you have in the light load cells in the rpm range you want to cruise at. A little extra fuel in that area as well. Will take some time to find what works best for that particular engine.

For example, light load at 1700 rpm might be something like 40-45 KPA at cruise. That area may need as much as 45-48 degrees or so. Think of it as vacuum advance added in that area and it tapers off as KPA increases (more throttle input, vacuum drops) This helps smooth the engine/cam, makes more vacuum at cruise and tends to be happier at the lower rpm cruise areas.

Fuel comes into play a bit as well but I like to start with timing first. With some work, you can have a fast car with quite a bit of cam in it and make it very docile to drive on the street everywhere all the time.

[Steve C.]

Crower rates the 66380X2 spring at 1.800" installed height with 173 lbs.

Page 172 here: http://www.crower.com/media/pdf/2008b/166-180.pdf

Paul K tested a set and found about 210 at 1.800"
Which brings up the subject to never trust catalog published specifications.
Always test your new springs at your actual verified installed height.


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[Formula8]

Originally Posted by Steve C.

Crower rates the 66380X2 spring at 1.800" installed height with 173 lbs.

Page 172 here: http://www.crower.com/media/pdf/2008b/166-180.pdf

Paul K tested a set and found about 210 at 1.800"
Which brings up the subject to never trust catalog published specifications.
Always test your new springs at your actual verified installed height.


.

Maybe I missed something but I have a 68380X2 and see 197 lbs @ 1.800 on the chart which goes to show you that you can't always trust your eyes either.

I believe I got them from Paul K so maybe he got those figures from my springs but I can't trust my memory either.

I am installed at an average of 1.830 so I think I am good either way. I have noticed absolutely no difference in either wear or performance with the new springs. Well, other than testing the limits of an .080 wall Pontiac pushrod.