# Cam advice (again)



## cij911 (Oct 25, 2017)

Well I think I have narrowed down the cam for my motor and would like a bit more guidance / advice / opinions from those of you that have gone down similar paths.

Motor details:

- 400 cubic inch block from a 68' Catalina (believe it to be stock / stock replacement)
- #16 heads (no porting, going to just slap them on) -- high compression but will run 91 + 2 cans of Torco per tank
- Tri power
- Dougs headers

Transmission & Rear
- Muncie 4 speed
- 3.55 differential

(I do have power disc brakes but could use a vacuum can if necessary)


What I am looking for - performance. I like the to drive the car. I enjoy winding it through the gears, heel and toe downshifting, and trail braking in the turns. I don't want a motor that is dead below 3k RPM, but I also don't want a cam that is dead by 4500 either. I'd like a cam that pulls hard to 5500 - 6000 RPM, but I can still be cruising around at 2500 with plenty of pep on hand.


The cams I am considering are:

1. Factory cam - 068....seems to perform well, requires nothing fancy in the way of setup or springs, and gentle on the valve train

2. Lunati Voodoo 702 or 703 cam... these were one of the last designs of famed cam designer Harold Brookshire and he felt it was his best....opens fast, but closes more gently than others...how the cam is degreed is essential

3. Crower 60242 or 90619....based in San Diego (less than 1 hour from me) and appear to be liked by several of the top builders....

Thanks

Chris


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## geeteeohguy (Feb 2, 2008)

You should talk to Cliff Ruggles on the PY forums. He knows his cams! I am running an obsolete Sig Erson High Flow 1 single pattern cam (106 lobe center, .479 lift, lots and lots of duration in my '65 GTO with high compression, and it screams. Would not be a good cam with power brakes, though. As for you cruising at 2500 RPM, you will be going about 50 mph at that RPM with 3.55's. Stock redline for a Pontiac is 5200 RPM....if you are running stock rods, I would not exceed that. I personally think you should install dished pistons and go with a faster profile cam designed for 8:1-9:1 CR engines. Adding boost or race gas gets old....real old. 
I think Cliff likes and uses Crower stuff....and it seems to be of high quality. With your gears, 4 speed, tripower, and headers, you will want more cam than an 068, IMO. And don't believe the myth that you can get away with high compression with a more aggressive cam. Not the case. The lost cylinder pressure at low rpms is more than made up for at mid range and high rpms, and it will detonate like mad under WOT if the octane is too low.


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## PontiacJim (Dec 29, 2012)

*bigD*, where are you?


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## 05GTO (Oct 6, 2004)

Chris,

In my opinion the 068 with a 116 lsa would have a good idle vacuum for the power disc brakes, I wouldn't go less than 114, the 2 Lunati cams are 110 and the Crowers are 112, another Pontiac cam to look at is the Ram Air IV 041 with a 114 lsa,
my 67 has a very nice (rough idle) sounding cam that was in the car when I found it, I added 4 wheel power disk brakes, when I go to stop I have to tap the accelerator to give me enough vacuum for the booster.


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## cij911 (Oct 25, 2017)

05GTO said:


> Chris,
> 
> In my opinion the 068 with a 116 lsa would have a good idle vacuum for the power disc brakes, I wouldn't go less than 114, the 2 Lunati cams are 110 and the Crowers are 112, another Pontiac cam to look at is the Ram Air IV 041 with a 114 lsa,
> my 67 has a very nice (rough idle) sounding cam that was in the car when I found it, I added 4 wheel power disk brakes, when I go to stop I have to tap the accelerator to give me enough vacuum for the booster.


I have a vacuum can I can use if there is an issue with brakes....Thanks 

Chris


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## bigD (Jul 21, 2016)

PontiacJim said:


> *bigD*, where are you?


Running low on home internet data transfer allowance for this pay period. Letting my wife have what's left. So, I have to drive to a small town, about 7 miles away. Was gonna use the internet at the public library. But, it was down. So, now I'm at McDonalds. 


"...What I am looking for - performance. I like the to drive the car. I enjoy winding it through the gears, heel and toe downshifting, and trail braking in the turns. I don't want a motor that is dead below 3k RPM, but I also don't want a cam that is dead by 4500 either. I'd like a cam that pulls hard to 5500 - 6000 RPM, but I can still be cruising around at 2500 with plenty of pep on hand..."

Well, 2500-6000 is a large power range. Can't go by the power range posted in cam descriptions. Some are ridiculous, & don't take into consideration the size of your engine, etc. 

I normally don't recommend an 041 clone cam for a street 400. Lots of guys have been disappointed with it. Great for a 455. But a lot of cam for a 400.

BUT, if you really wanna wind it to 6000 rpm, on a regular basis, I'll have to recommend an 041 clone, but ONLY with Rhoads lifters. Without the Rhoads I'm afraid you won't have much power below 3000 rpm. Will also help calm the nasty idle. The cheapest 041 clone is a Melling SPC-8, from an Ebay seller. Summit will usually match or beat the best legitimate price you can find. 

https://www.ebay.com/itm/Engine-Cam...634348&hash=item261eb2f235:g:tdUAAOSwtAtboHby

https://www.amazon.com/Rhoads-Lifters-RL9518-Hydraulic/dp/B019XANKNQ

The 9518L lifters have a groove cut, to direct more oil onto the cam lobes. 

https://www.jegs.com/i/Rhoads-Lifters/817/9518L/10002/-1

(2) If you can't stand the ticking sound the Rhoads lifters make, my next choice would be a Howards 410051-14. It has less adv duration than an 041, but similar duration @ .050 lift. 

https://www.summitracing.com/parts/hrs-410051-14/overview/make/pontiac

The best lifters, next to Rhoads, are the Hylift Johnson "R" lifters. They bleed down, slightly, below 3000 rpm. Not nearly as much as Rhoads. But, enuff so that they don't make the very noticeable ticking sound which the Rhoads a famous for. Rhoads are said to be modified Hylift Johnson cores. 

http://toplineauto.com/wp-content/uploads/2019/04/Lifter-Application-Catalog.pdf

(3) Right under that might be a Crane 283521. 

https://www.summitracing.com/parts/crn-283521/overview/make/pontiac

(4) Next might be a Crower 60243. But they're $200. Don't know why they're higher than most any other brand.

https://www.crower.com/camshafts/pontiac-287-455-compu-pro-hydraulic-cam-284-hdp.html

(5) Next might be a Crane 283951.

https://www.summitracing.com/parts/...EixRF9nyONKDNg0eySh9VIuf6FmIYCaIaAusEEALw_wcB

(6) Next might be a Howards 410141-12.

https://www.summitracing.com/parts/hrs-410141-12

(7) Next might be a Summit 2802. I bought this for my current 455 bracket car, because it's a SUPER LOW budget build. I used the 041/Rhoads in almost all my 455 bracket cars, back in the old days. 

https://www.summitracing.com/parts/...-RzGGxietZQw_KF_FlLQq1jbmLPSeP7RoCJdgQAvD_BwE

If you get much smaller than this, you'll have more low end, but less top end. Don't think anything smaller will still be pulling very much past 5000 rpm. Don't mean they won't rev to 5500. But the power will be falling off enuff to feel it. 

All this is assuming the heads work good & the rings still seal good. Obviously, if either the valves or the rings are not sealing, compression & power will be lost.

Some say that around 220° @ .050 is enuff intake duration for a street 400. If you wanna go that small, the Lunati 10510312, should be decent. Don't know about revving past 5500 tho. Has less lift than most of those listed above. So, could probably get by with less valve spring pressure. Would definitely have a smoother idle, more vac, & more very low rpm torque. 

https://www.lunatipower.com/street-master-hydraulic-flat-tappet-cam-pontiac-v8-276-286.html

https://www.ebay.com/itm/Pontiac-V8...937061&hash=item420a72d9bf:g:LYAAAOSwmrlU0mJ9


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## cij911 (Oct 25, 2017)

Well, I've been told to keep the RPMs below 5500 because of the stock rods....

The two cams that seem to be recommended a lot are the Lunati 703 & 704. My plan is to send the #16 heads to Paul Carter in Tucson and have him go over / prepare them.

Thanks for your help everyone!


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## Lemans guy (Oct 14, 2014)

I think we may have talked about it months ago Cj, Lunati will grind you a custom cam for another $50 .....above the cam costs

Give them a call tell them what you want.....what you are trying to achieve.....they are real helpful

but you won’t go wrong with anything BigD says on those,...he knows em.

Sure the others makers will custom grind as well....


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## PontiacJim (Dec 29, 2012)

cij911 said:


> Well, I've been told to keep the RPMs below 5500 because of the stock rods....
> 
> The two cams that seem to be recommended a lot are the Lunati 703 & 704. My plan is to send the #16 heads to Paul Carter in Tucson and have him go over / prepare them.
> 
> Thanks for your help everyone!



Not so much the rods as it is the rod bolts - they can stretch causing the cap to "oval" and pull in at the parting line and act as a scraper and scrape the needed oil off the crank journal - thus damaging or wiping out the bearing and producing that ugly rod knock familiar with a bad/spun bearing.

The 704 has too much lift. Unported heads typically flow good to about .450" lift and don't show much flow over that. A 3-angle valve job will give you some more flow, but I would keep it under .500" lift. Your stock valves may not be adequate in length and you will have coil bind. The longer RA IV valves might be needed, as well as matching springs & retainers for both the valves and cam lift. You would also want to check valve-to-piston clearances to make sure the pistons don't slap the valves.

So out of those 2 picks, the 703 would be the better choice in my opinion. :thumbsup:


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## bigD (Jul 21, 2016)

If your actual CR is much over 9:1, I wouldn't run a Voodoo. They have steep ramps, which increases cyl pressure. 

BUT, Paul Carter recommends a Voodoo for almost everything. So, I'd expect nothing else for your app. 

He also recommends LOTS of spring pressure, more than most, when running a Voodoo. Unless shooting for max power, I'd go with less cam & spring pressure. 

If you want a max power build, Paul Carter can do it. It's your car, money, & call.


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