CRG Discussion Forum

Camaro Research Group Discussion => General Discussion => Topic started by: G Smith on May 11, 2019, 01:23:44 PM

Title: Cam for my 1969 302ci
Post by: G Smith on May 11, 2019, 01:23:44 PM
Hi Guys what do you think Comp cam Nostalgia Plus or Factory Muscle 30-30 any help would be appreciated
Title: Re: Cam for my 1969 302ci
Post by: x66 714 on May 11, 2019, 02:02:53 PM
It's been years since I was into my 302 but at that time I used one on the 3849346 Crane Blueprint cams...Joe
Title: Re: Cam for my 1969 302ci
Post by: BillOhio on May 11, 2019, 02:08:22 PM
I will get x33rs to check in. He had somewhat of a cheater cam for his 302 that works real well. 
Title: Re: Cam for my 1969 302ci
Post by: 69Z28-RS on May 11, 2019, 02:10:22 PM
Hi Guys what do you think Comp cam Nostalgia Plus or Factory Muscle 30-30 any help would be appreciated

I think most of the major cam makers (including Lunati) have grinds that 'mimic' the Z28 grinds...   just depends on what you want.  I have an NOS '69 Z28 cam in the tube, but not sure I'll ever use it.   I have a Lunati 'blueprint' cam in my 302 right now, but *thinking* about using a roller version in a future rebuild...?
Title: Re: Cam for my 1969 302ci
Post by: X33RS on May 12, 2019, 03:39:49 AM
Yes I've told Bill what I've done to the engine.  When I built our 302 I had the pure stock drags in mind as that's what I built one of our Pontiacs for.  So a lot of attention to details and the camshaft was a big player.  Per rules lift and duration can't be increased so it's still similar to the original cam with tweaks.  The lobe profile is a modern design with a faster ramp, and is a tight lash at .014".  I preferred that to keep the beating to a minimum as longevity was also a concern. Turns out my wife drives this thing daily and has logged 30k miles in the last 2 1/2 years. 
   The rules only state max advertised lift.  In our case that's .485 but the problem with solids is the loss of lift with lash, and on a stock cam that's .030".  Since advertised lift was the goal, per rules, the lobe is actually a .495" lift, with .014" lash giving me .481" lift, within advertised lift, and more than a 30-30 would have with it's lash figured in.   See how rules can be manipulated?   Duration is the same but there are no rules for LSA, so that was tightened up to 112 to bring in the torque curve a little sooner.  Installed on a 110 ICL which also gave me the int/exh valve relationship I was looking for at TDC during overlap.
   The cam does what I wanted, more power sooner in the rpm range, still pulls to 7,000 with a very broad flat curve, still makes 9-10 inches of vacuum at 5,000 ft elevation (14 inches at sea level) and drives around really nice and with a true 11:1 compression it's running perfect on our crappy 91 octane pump fuel.  Idle is very close to stock with maybe a slight hint of more attitude.
If I were to build the engine again, and forget about the PS rules, I would likely go with something completely different as there are more improvements that could be made, but this was in the interest of experimenting to see what could be done with it.

https://youtu.be/IZ0HlEY7b74   
Title: Re: Cam for my 1969 302ci
Post by: 68camaroz28 on May 12, 2019, 01:37:57 PM
It's been years since I was into my 302 but at that time I used one on the 3849346 Crane Blueprint cams...Joe
Had to laugh Joe as I bought and used a crane blueprint cam but bought it in the early 80’s, so yea a lot of years ago even though the engine was not done until almost 30 years later.
Title: Re: Cam for my 1969 302ci
Post by: x66 714 on May 12, 2019, 01:55:04 PM
It's been years since I was into my 302 but at that time I used one on the 3849346 Crane Blueprint cams...Joe
Had to laugh Joe as I bought and used a crane blueprint cam but bought it in the early 80’s, so yea a lot of years ago even though the engine was not done until almost 30 years later.
Lots of stuff changed after the engine was built. I remember buying 12.5 to 1 pistons & shaving .200 of the domes to get to 11 to 1. Also opened the ring lands so I could use stock rings. I think today you can buy closer to stock pistons & better cams but that's what I did then. Still runs strong. Factory 4.56 gears help :) 
...Joe
Title: Re: Cam for my 1969 302ci
Post by: bcmiller on May 12, 2019, 02:52:40 PM
Depends on what you are going to do. Back in the late 70s when my dad was drag racing a 67 Camaro with a DZ 302 one of the cams we ran was a custom ground Crane 0.620 lift solid roller, 13 to 1 compression, angle plug shaved heads, magneto and ran on aviation gas with an M21 and 4.88 gears.

Cam manufacturers used to have a number to call and would help get you what you want based on your setup and goals. Not sure they do that any more.
Title: Re: Cam for my 1969 302ci
Post by: firstgenaddict on May 18, 2019, 03:07:03 PM
I would run a solid roller, you will not believe how it revs  and EVEN with what seems to be a ridiculously high lift how much vacuum it will make.
The biggest factor in cam design is the flow of the heads. IF you have stock 186's there are numbers out there which are more than adequate to provide to the cam company.
The runners on stock 302 heads have a small volume according to Crower, so you need to get the valves open quick and leave them there to make power, he doesn't slam them on the seat either... lets them down quick almost to the seat then the ramp is very soft so as not to slap the valves into the seats.
Dave Crower designed a killer solid roller for our 302 which made tons of vacuum and lots of low end torque.
Gross lift was .636 and the duration was in the 270-280 range made 14" vacuum and 350 ft lb torque by 3500 RPM. over 500 HP.
 
Title: Re: Cam for my 1969 302ci
Post by: ZLP955 on May 19, 2019, 01:20:24 AM
James did you have to use taller valve covers with the >0.6 lift?
Title: Re: Cam for my 1969 302ci
Post by: firstgenaddict on May 19, 2019, 06:26:13 AM
Thanks for asking, until you asked I had not remembered.
I was running needle bearing roller rockers with 69 covers (without drippers) BUT with a thick and thin felpro gasket glued together and then into the valve cover. This photo shows the AL needle bearing roller rockers.

(https://lh3.googleusercontent.com/j8mcI7trodC4AzcPOjyoXSs9JpEaImxZ8IkY98SoEC0AaBITbXTPJicj72JKwNSbsYUJfxsUpTXfk_JGf8Lx5J9usFJX13jSau9PTS_M-fycntaIPIVho79ANfe7x7PxzhEutavFkfvg85QmgNuIKm7F49EQfijpbSnTCodYWeK7hpSFRM85KIrRMGNvKovrgviyWWBvmuc3ggU_aGMTs3DeUee82FeWamScB-zNE_J0DHOhtliqqjX47QAhklaEEyOrv0KgZ5w8pObrzw2NBMtpzjx55_3IxcAjOFI1sBrZH8nngnZzEMTSOlZ9cAH_cgU-l_guE4mNwtCiBg-m6v3t4G-bVo4D2JM-5B10t69_BDfPjTDulHDVu_Kd5lIJbyNQ7NCe-lVOu4xFqMj0qctjrX2rMFtu4ZPRpGhiANBiej7MA1DFfdcJ7_oNr55O2WjO3EFwFtOhpvanSDftB-gX9IC7ue2HungvIoyP4OO3QCG5HVqzgzzL4C6-rsFnMLDa9vaMLzx0Iyz1DWKMBjJ4ksifZulV3PmL4nhO45BWCCnGgysP3tK_agXDFkL4kR2UU6M1kq75OcFEPCLic178M-bYu485V8S832yMGPOv-EXT3pjvGhqDADCwmfb8m8OfVmack-PrOL5pzy8FLAVEchuOfIxK62W2oZey1RN_Vu3n0U95a9emrLRubdNRNjeukKuLEGmbeIkEbxJa5dVN7g=w1538-h1153-no)
Title: Re: Cam for my 1969 302ci
Post by: ZLP955 on May 19, 2019, 09:54:43 AM
Thanks for confirming those details James. Impressive numbers, but I bet far more important was the way it drove and felt compared to a stock Z.
Title: Re: Cam for my 1969 302ci
Post by: firstgenaddict on May 19, 2019, 10:52:54 PM
Yes, Dave Crower asked if I wanted a dyno queen that  would post a number or something that would destroy a dyno queen every day on the street or the track...   consider that when you look at the numbers as well = THAT's what is really amazing, if I just wanted a number, what would it have been? 600?
The fat torque curve is what was FUN!
Made the car easy to drive.
Title: Re: Cam for my 1969 302ci
Post by: camaroboy68ss on May 20, 2019, 08:07:05 PM
I have the Comp Nostalgia Plus 30/30H in my 68's 327. I've been running in now for a couple years and i like the cam. Has a great lump at idle. It replaced a GM L79 cam and that swap really woke that 327 up. I do wish I went with a solid lifter cam instead of the hydraulic version now, but overall I have been happy with it.
Title: Re: Cam for my 1969 302ci
Post by: crossboss on May 20, 2019, 10:07:37 PM
I would run a solid roller, you will not believe how it revs  and EVEN with what seems to be a ridiculously high lift how much vacuum it will make.
The biggest factor in cam design is the flow of the heads. IF you have stock 186's there are numbers out there which are more than adequate to provide to the cam company.
The runners on stock 302 heads have a small volume according to Crower, so you need to get the valves open quick and leave them there to make power, he doesn't slam them on the seat either... lets them down quick almost to the seat then the ramp is very soft so as not to slap the valves into the seats.
Dave Crower designed a killer solid roller for our 302 which made tons of vacuum and lots of low end torque.
Gross lift was .636 and the duration was in the 270-280 range made 14" vacuum and 350 ft lb torque by 3500 RPM. over 500 HP.



Those are some very impressive numbers! That said, a solid roller cam is not for everyone. It will require a lot more maintenance for a street/performance car. It all boils down to want you are trying to achieve. Personally, 'I' would suggest a nice modern hydraulic roller camshaft grind. The small block Chevy has more R&D than ANY engine in existence, so finding the 'right' cam is out there…for each one's taste in driving style.
Title: Re: Cam for my 1969 302ci
Post by: pjbizjak on May 22, 2019, 02:36:21 AM
I recently installed the Comp cam version of the 30/30 in my 68 z/28 302+. Sounds great but haven't road tested it yet. Currently in the paint shop.
Pete
Title: Re: Cam for my 1969 302ci
Post by: X33RS on May 23, 2019, 02:07:31 PM
Seems even the so called repop copy cams are tinkered with a bit.  I have one here in a box that was bought 25 years ago and even then they were changing the specs.  I found out later it's actually advertised as a copy of the 30-30 but they ground it with 2 more degrees of advance than the OE cam had.   Guess they believed even then they could improve on the characteristics of the engine, and when I had the guy on the phone a couple years ago he confirmed they were trying to build a little more low end torque in the engine.  Oddly they still advertised it as an OE cam.

I couldn't help but wonder after that phone call that cam companies are likely still doing this today, and wouldn't surprise me if they are doing them with slightly different lobe profiles then before.  I doubt any of them have the lazy GM lobes and really wide LSA's with little advance that the OE cam had.

One of the things we did on my cam, since it was a custom deal that would only mimic the original in lift and duration only, was to use a lobe profile that had a soft closing ramp, similar to the GM cam design, so it was easy on the seats.  It also has a late opening exhaust in an effort to build more torque.  A tight lash was also something considered mainly for stability and longevity.   Explained straight from Harold,  "With tight lash the pushrod hits the same spot in the rocker, reducing shimmy, which effects spring life.....  Very wide-lash cams cause the pushrod to hit all over the place, and the resulting vibrations/shimmy is translated to the valve and spring."
  Some other things I did was to nitride the cam, and also run a solid lifter with an EDM hole that shoots pressurized oil right on the lobes.  All done in an attempt for longevity.

I've shied away from the solid rollers in street engines.  They require quite a bit of spring seat pressure to control the valves, more so in engines like Pontiacs or BBC's that have heavy valve trains in them.  Not so much in a SBC but still more spring seat pressure than I care for in a street engine.  What happens over time is usually a lifter eats itself if you drive it enough.   We had this very thing happen on my fathers engine.  Most aggressive solid rollers in a street application typically have 240-260 lbs. seat pressure.  His was 240.  We even used the very expensive Crower bushed rollers with pressurized oiling on the rollers.  After 6,000 street miles one lifter ate itself, taking the cam with it.  Have since switched this engine over to a hydraulic roller.  Typical aftermarket hydraulic rollers use about 150 lbs. seat pressure and around 400 lbs. open.   
Title: Re: Cam for my 1969 302ci
Post by: crossboss on May 23, 2019, 03:58:14 PM
Most OEM camshafts are ground 2-4 degrees retarded for emissions. What the aftermarket does is grind the same cam 2-4 degrees advanced to achieve some low end torque, and gain back some performance improvements. I also agree, an aggressive solid cam for a street/mild performance set up is really not worth the extra hassle. Heavy spring pressures, radical lobes, small base circles, can result in premature failure on the valve train….IF not watched/maintained carefully. With modern hydraulic rollers, you get the best of both worlds…reliable performance, relatively low maintenance, and RPMs. That said, anyone who wants the 'correct' cam will go with the OEM solid lifter version.
Title: Re: Cam for my 1969 302ci
Post by: X33RS on May 23, 2019, 08:13:05 PM
That said, anyone who wants the 'correct' cam will go with the OEM solid lifter version.

Agree, and even though I was confining myself to rules when I did mine at the time, I still would have put a solid flat tappet cam in the engine if I were free to do what I wanted.  Very doubtful it would have been OEM and most certainly nothing off the shelf,  since lobe profiles today have come a long way, but it would be a solid flat tappet none the less, because I don't want to get away from the nature of the engine and what it was intended for.
Title: Re: Cam for my 1969 302ci
Post by: crossboss on May 23, 2019, 11:03:01 PM
That said, anyone who wants the 'correct' cam will go with the OEM solid lifter version.

Agree, and even though I was confining myself to rules when I did mine at the time, I still would have put a solid flat tappet cam in the engine if I were free to do what I wanted.  Very doubtful it would have been OEM and most certainly nothing off the shelf,  since lobe profiles today have come a long way, but it would be a solid flat tappet none the less, because I don't want to get away from the nature of the engine and what it was intended for.



Absolutely correct. When I vintaged raced my T/A car, the rules 'required' us to use a solid lifter (a special larger radius tappet) experimential grind within the 'specs' of the rules concerning lift and duration. Yes, it was quite radical with 636 lift, 338 degrees duration, with a lobe center of 104. Idle quality was at 2,500 RPM….not street able for most guys.
Title: Re: Cam for my 1969 302ci
Post by: janobyte on May 24, 2019, 12:31:59 AM
Guys head's probably spinning now, lol.

We run a hydro roller in the Anglia, .610 lift, 308 duration. Custom grind for the application, all the specs are in a folder out in the shop. Love it. Shift points 7400, responsive as a variable drill motor. No "hit", smooth idle, good vacuum. Hp/torque crosses at 5500, lines run parallel post. Builder went with heavier springs then the Dart's. No valve adjustments with the sun reflecting  off the chrome,,in the pits.

That being said, I'm keeping the old school Comp. hydro in the 302. With,gasp, Rhodes lifters. Same lift/duration as the 30-30. Doesn't "slam" the valves like the 30-30. Choppy idle, good vacuum, advertised float at 6500, however began laying down around 7200.

So,,all depends what you are doing with the car. Mild cruiser, making alittle noise, sleeper, or are you running a 14:1 with a set of .208's. Sounds like x33 has the set up, but, that's the package he had in mind, to suite his( and his wife's, who daily drives it) needs.
Title: Re: Cam for my 1969 302ci
Post by: janobyte on May 24, 2019, 01:06:43 AM
Somewhere on here I have a copy of the cam card posted.
Title: Re: Cam for my 1969 302ci
Post by: Stingr69 on May 24, 2019, 12:48:37 PM
I am running a 302 with a Crane 113841 solid flat tappet.  Has .050" open and close points that are very close to the LT-1 cam specs but somewhat faster ramps and higher lift.  Third time using it.  Needs 130# seat with 350# over the nose for best RPM performance.  3000-6800 basic RPM range, valve float at 7400 per Crane.  PAC 2600 springs will do it and fit stock valve spring pockets.  Whats not to love?

I am putting a 355 together with it now.