Re: Correct me if I'm wrong ............
 

Rob;
You found that style at the local parts store? That's where I'll go, let me know if you have a part number or a particular way of describing them to the 'Import Fanatics' that work at my local stores.

I won't say 'no' to seeing you guys at Norwalk, but I may run out of time to get the car dialed in - maybe I'll just use that as a test-n-tune, but wouldn't want to be embarassed if my stuff can't run a good number yet. This stuff is all new to me, I'm used to a hydraulic cam, quadrajet, and a/t = just stand on it all the way through the traps [img]/ubbthreads/images/icons/grin.gif[/img]

Re: Correct me if I'm wrong ............
 

A hydraulic cam, a QJet, and an auto ....... and it's just *Stab-N-Steer*, 'eh ??? Hmmmmmmmmmmmmmmmmmmmmmm....... [img]/ubbthreads/images/icons/grin.gif[/img]

First spring clamps - THEN you guys are gonna start letting him know about Polyglas tire pressures ........ SHHHHHHHHHHHHHH !!!!!!

Re: Correct me if I'm wrong ............
 

Sorry Casey, I should have added; 78 el camino 350, low compression, no cam, no tuning! Add to that a sleepy Th350 with shift kit, and an open end 3.08 geared 10 bolt. Plus, 145k miles on the stock suspension. It was a slow ride, but a fun time.

Don't worry, I know who won the battle of the small block in MCR - where was Pete and JJ on that day [img]/ubbthreads/images/icons/grin.gif[/img]

Re: Correct me if I'm wrong ............
 

Robs local parts store is pretty special if I do say so myself. [img]/ubbthreads/images/icons/grin.gif[/img]

Mr. G. 1293

WHAAAAAAAAAAAAAAAAAAT ?
 

Marlin,

If it didn't have a camshaft in it - it needed one. We'll work from there.......... [img]/ubbthreads/images/icons/shocked.gif[/img]

Re: WHAAAAAAAAAAAAAAAAAAT ?
 

<blockquote><font class="small">In reply to:</font><hr>
Robs local parts store is pretty special if I do say so myself.

Mr. G. 1293

<hr></blockquote>

There you go, M! It's nice having your parts man online!

Re: WHAAAAAAAAAAAAAAAAAAT ?
 

Thank you gentlemen!

Casey, allow me to rephrase [img]/ubbthreads/images/icons/grin.gif[/img] 'The cam was not a hi-performance cam'. I drove it back and forth to college, so I guess it had some kind of broomstick in there, [img]/ubbthreads/images/icons/confused.gif[/img] it was a fun car, but it had to go!

Re: WHAAAAAAAAAAAAAAAAAAT ?
 

Marlin, I'm sure Copo Pete and Jimmy J. have lots of experience behind the wheel of a 4 gear LT-1 Nova, and would probably be glad to give your b-e-i-g-e car a few shakedown passes. You know, just to make sure its safe and all like that. [img]/ubbthreads/images/icons/wink.gif[/img]

Re: WHAAAAAAAAAAAAAAAAAAT ?
 

Let's tell Marlin that he needs 25PSI in the rear of the WideOvals .......... and 30 in the front .......... come ON, I CAN'T have an LT-1 Nova spank me ..............

Well - OK, maybe ..... b e i g e is the insert color on my Ford dually .......... [img]/ubbthreads/images/icons/grin.gif[/img]

OK - I'll be kinda nice .......
 

Marlin,

With these tires, the trick is to not blow them away coming out hard.

For example: With my W-31, I have a $53 reman'd Dynamic converter that seems like it is about 15" in dia. It lugs the motor enough from a "dig" that it allows the tires enough time to bite before the motor "comes on". I also run a LOT of advance in the distributor. Basically - off-idle, it is at full advance, which also helps the low end.

OK - THAT's it from the Olds Corner !!!!! [img]/ubbthreads/images/icons/grin.gif[/img]

Marlin's a scardey-cat to race his Deuce ......

Hey Marlin - My W-31 went MID-15's it's first year out. Don't worry 'bout it dooood.

Marlin's still afraid an Olds may beat his lil'ole Nova .... [img]/ubbthreads/images/icons/smirk.gif[/img] [img]/ubbthreads/images/icons/smirk.gif[/img]

Re: OK - I'll be kinda nice .......
 

Hmmmmmm [img]/ubbthreads/images/icons/grin.gif[/img]

So, what tire pressure do you start with in the rear's and front's? I thought the rears got 15-18, and the fronts got 40 psi??

What about a blocked power valve in the secondary of the Holley's? Is that as beneficial as I'm being told? Before I had my Holley 'concoursed', I had a block in the sec's, and the car would really come-on at about 2500 rpm - but I couldn't keep the tires under it. I later read in the Holley book that this scenario is caused by a lag in the fuel delivery, and although it feels cool, it's not the best way to set up the carb. So, I've not re-installed the block, it's not breaking the tires loose, but it takes longer to get the same seat-of-the-pants power.

I won't know what this thing will do for sure until Spring, then I will have a chance to take it out and test a few things. Even if I don't make it to one of the Pure Stock events, I'll get it to my local track.

So, Casey, I just might pull up next to you in the other lane one of these years [img]/ubbthreads/images/icons/grin.gif[/img]

Re: OK - I'll be kinda nice .......
 

You shouldn't have any trouble hazing the tires, so I advise AGAINST running that low of pressure in your rear tires! I would hate to see you put that thing in the ditch this early into it's restored life!

I think the general rule of thumb (on repro bias-plys) is to start around 40 and work up. Our Camaro runs 46psi on all 4 corners, but this is dependant on the car/tires...but it should get you in the neighborhood. Lay a set of black marks and make sure they are each nice and evenly dark all the way across. Adjust the pressure according to what you find.

My first year I tried lowering the rears to ~20psi...I almost took out the Christmas tree and both guardrails[img]/ubbthreads/images/icons/crazy.gif[/img]!

Re: OK - I'll be kinda nice .......
 

Marlin,
I remember a friend who owned a Belvedere(sp) Mopar ran a low air pressure like that in his rear tires with the same almost devastating results! He said it was quite the scary ride down the track. Next time I see my friend Steve (The guy I talked about in the NNN article) I'll ask him if he has any tips for you since he raced Novas for years. Even stuck a 427 in his 70 at one time.
Ron

Re: OK - I'll be kinda nice .......
 

I'm not sure that I understand how the lower rear tire pressure would cause the car to launch 'crooked'?? I thought the tire would 'flatten out' a little bit as it absorbed the initial 'shock' and thereby give a little better launch because you could hit the tires with a higher RPM?? Remember, this is completely new to me!

Another Olds freebie .....
 

Similar to Rob....

I run 48 psi in the front, and 44 psi in the rear. I've found that is where I get the most consistent contact patch for the tire in the rear.

If you put in the 32 psi recommended pressure, and do a quick blip in your driveway (OK - I do them in my driveway ......) anyway - - - you'll most likely find that you will see the outside edges of the tread making the darkest contact, and the inside 4 inches or so of the tread will be a simple *wisp* of black. As you air up the tire, the distance of the dark patch should get closer and closer, until you have a nice flat contact patch across the entire tread width of the tire. If you look at a Polyglas, there really is quite a bit of rubber that makes contact - as long as it ALL is making contact. Also, it seems to be fairly agreed upon by the Pure Stock guys that the more *seasoned* tires actually get BETTER traction with use. READ: DO LOTSA BURNOUTS to season them !!!! [img]/ubbthreads/images/icons/smirk.gif[/img]

Re: Another Olds freebie .....
 

Marlin:

It wasn't that it "launched crooked", but the wheelspin got pretty bad...I pedaled it for a ways down the track, but when I got back into it, mayhem ensued! Luckily I can't leave off the converter anyway, so I was leaving pretty much from an idle, but it still spun it sideways HARD. It was probably a good run to WATCH, but made for a terrible ET/MPH!

Re: Another Olds freebie .....
 

I seee....

Re: Another Olds freebie .....
 

Marlin, A bias tire reacts different than a radial. (obviously) When air pressure is low it causes the bias tire (also Radial) to react like it is flat. You feel like you are getting a flat tire and the car vears all over the road. You need to do a burn out and see how the tire is planting itself. Look at the marks and see if you have a full tire width on the ground. If not, add or subtract air till you like your burn out marks. If the tire pressure is too low you could possibly spin your tire in its rim. It is trial and error, but we have faith in you. Just don't be upset if the car doesn't get out of the mid 14 teens set up like that. I can see day 2 is just around the corner! Ha-Ha Sam

Re: Another Olds freebie .....
 

Casey,
It seems that I am chasing you around. Maybe I can keep you from getting in trouble (not). I was needing to talk with you about a driveshaft loop. Can you reply to me here or send me an e-mail. To everyone else, Hi! [img]/ubbthreads/images/icons/grin.gif[/img]

Re: Correct me if I'm wrong ............
 

Neat forum..... Good to be back amongst GM people.

Casey's loop works well on my Ramrod, but lots of vibration to the floorboard. One that mounts between the trans mount and the trans is junk, it throws your dive train angle wayy off and reduces the clearance between the driveshaft and the floorboard to the point that we had to cut away the top 180 degrees to clear. At that point it was no better than the H pipe. We snapped a driveshaft first year at PS drags at the top end. Also took out the bellhousing. Scary.

Love this smiley: [img]/ubbthreads/images/graemlins/3gears.gif[/img]

Re: Correct me if I'm wrong ............
 

I found my Cam Card for the cam that I put in my Yenko. Where can I go to find the spec's for the stock LT1 cam from GM/Crane?

If I list the spec's for both cams, can you guys predict how my Comp Cam will perform compared to the stock Crane?

Re: Correct me if I'm wrong ............
 

I believe THIS is your card.

Re: Correct me if I'm wrong ............
 

Cool,
Thx,
[img]/ubbthreads/images/graemlins/smile.gif[/img]

Re: Correct me if I'm wrong ............
 

Original 2182 Cam;

Lift: In; 459 Ex; 485
Dur @ .05: In; 242 Ex; 254
Centerline: 116 (I think)


My Comp Cam;

Lift: In; 510 Ex; 530
Dur @ .05: In; 242 Ex; 250
Centerline: 106


Rob/Pete/Sam;
Is there a big difference in rear wheel hp/tq between these two cams since I'm using the stock manifolds, smog pump, and Gardner Exhaust with resonators?

Re: Correct me if I'm wrong ............
 

Marlin, That seems to be a pretty high lift cam. Sometimes your rpm's and torque are hindered with a very restrictive exhaust.Your engine can not breathe properly, hence performance is hindered. Too much cam and no headwork can hurt also. Do you have enough vacuum to stop? Sam [img]/ubbthreads/images/graemlins/eek.gif[/img]

Re: Correct me if I'm wrong ............
 

CHEATER [img]/ubbthreads/images/graemlins/3gears.gif[/img]
Peter

Re: Correct me if I'm wrong ............
 

I have plenty of vacuum, 18 at idle. The only thing I wanted was a lower C/L, to keep some compression into the engine at lower rpm. I agree the extra lift is irrelevant due to the factory manifolds, smog (not cheating!) and factory exhaust with resonators (not cheating!!).

If I could do it over again, I would probably go with the Crane since I really don't drive it that much. And, so Pete wouldn't bust on me some day at the track [img]/ubbthreads/images/graemlins/grin.gif[/img]

Re: Correct me if I'm wrong ............
 

[ QUOTE ]
CHEATER [img]/ubbthreads/images/graemlins/3gears.gif[/img]
Peter

[/ QUOTE ]

If that isn't the Pot calling the kettle Black!
Just light hearted ribbing Pete. [img]/ubbthreads/images/graemlins/grin.gif[/img]

Re: Correct me if I'm wrong ............
 

Yea!! What he said!
Mr M20 trans and no smog [img]/ubbthreads/images/graemlins/grin.gif[/img]

Re: Correct me if I'm wrong ............
 

Marlin:

Just curious...is this your current cam (from Comp)? Check the part number &amp; specs and let me know...

Re: Correct me if I'm wrong ............
 

Marlin,Marlin,Marlin, Please just GO to day 2. And all your troubles will be gone! [img]/ubbthreads/images/graemlins/no.gif[/img] [img]/ubbthreads/images/graemlins/naughty.gif[/img] [img]/ubbthreads/images/graemlins/dunno.gif[/img] [img]/ubbthreads/images/graemlins/confused.gif[/img] [img]/ubbthreads/images/graemlins/haha.gif[/img] Sam

Re: Correct me if I'm wrong ............
 

Rob;
That's the one! Part number matches.

Sam;
No day two for me, I'm actually considering putting the original Crane cam in [img]/ubbthreads/images/graemlins/smile.gif[/img]

Re: Correct me if I'm wrong ............
 

[ QUOTE ]
Rob;
That's the one! Part number matches.

Sam;
No day two for me, I'm actually considering putting the original Crane cam in [img]/ubbthreads/images/graemlins/smile.gif[/img]

[/ QUOTE ]
OH MY GOD!!!!!!!! BE STILL MY LITTLE HEART!!!!
Peter [img]/ubbthreads/images/graemlins/biggthumpup.gif[/img]

Re: Correct me if I'm wrong ............
 

Crane was not the original cam! Chevy was. Try to find an early nos cam, because chevy standardized these cams and I personally don't think they are as good or as accurate as the originals. I have a Crane speck cam in my Z/28, and frankly it just does not have the snap as the early chevy sticks had. I don't know why you would go to all that trouble any how. sam [img]/ubbthreads/images/graemlins/crazy.gif[/img]

Re: Correct me if I'm wrong ............
 

I can understand the 106 LCA helping with the low compression, but the 106 LSA sounds REALLY tight to me! How does that thing idle, Marlin? Does the advanced LCA make up for the tight LSA? Anyone?

As for the Crane vs. GM discussion, I tend to believe it's the opposite. JJ's "143" (from Crane) was spot-on when they checked it at the Certified Stock tech. And, as I mentioned earlier in the thread, Lerum put an NOS GM "143" on a cam doctor and all of it's specs were all over the place, from LSA to lift. Just my opinion though...

Whatever you decide on cams is your business, but I expect to see that thing on the track!

Re: Correct me if I'm wrong ............
 

Rob;
Not sure what LCA and LSA mean, and how they might relate to each other? My car idles a little high, but I think the secondary throttle plate is hung up a little. I took it off to adjust that, but not sure if I corrected it or not. Other than that, the car idles fine, 18inches of vaccuum at idle so....

The durations of the two cams have not changed, so why would I have a problem with the vaccuum supplied to the brakes? Only the lift is up, and when you check the cam profile the increased lift has minimal effect due to the same duration. Plus, the original manifolds, heat riser and smog stuff stifle any lift advantage [img]/ubbthreads/images/graemlins/frown.gif[/img]

Thoughts? Constructive ones, Pete [img]/ubbthreads/images/graemlins/smile.gif[/img]

Re: Correct me if I'm wrong ............
 

Marlin,

LCA (Lobe Centerline Angle) is a term that tells you how advanced your cam is. If you have a cam that has 114 degree LSA (Lobe Seperation Angle)and you put the LCA at 106 degrees you've advanced you're cam 8 degrees.

This would generate good static compression at low RPM but hurt high RPM cylinder fill. It will close the intake valve approximately 8 degrees sooner. What you get on the bottem end you give up on the top end. Alot of how the cam should be put in depends on your car set up. ex. 4 speed or automatic, 4.10 gears or 3.55, high compression motor or low low compression motor. [img]/ubbthreads/images/graemlins/beers.gif[/img]

JIM

Hope this helps! [img]/ubbthreads/images/graemlins/flag.gif[/img]

Re: Correct me if I'm wrong ............
 

Sorry about that, Marlin! Jim's right on the money with the acronyms:

LSA - Lobe Seperation Angle
LCA - Lobe Centerline Angle

The LSA is the amount of serperation, or overlap, between the intake and exhaust lobe. The "wider" (larger) the number, the less overlap, and the more fuel/air that is trapped in the cylinders at low/mid engine speed, and vice versa. This is ground into the cam, and thus, can't be changed. This also has a great effect on idle, and anything under 112 will generally have a pretty good lope to it (that's why I questioned the 106 LSA of the Comp unit). I believe the LSA of the 143 cam is 114, and I think the original LT-1 cam is the same (114). The LSA is independant of the LCA.

LCA is the centerline of the intake lobe, and like Jim said above, tells you how much your cam is advanced/retarded. This is changed by degreeing your cam to whenever you want it to come in. I believe most of the older/original cams were ground advanced (the 143 cam was ground with 6 degrees advance!), which is fine on the stickies, but is hard to handle if you are running on the skinnies!

Re: Correct me if I'm wrong ............
 

Thanks Rob/Jim;
I think I have a little better understanding of the LSA and LCA. When I installed this cam I was looking for better driveability, not for Certified Stock!

I think the stock LT1 cam is 116 degrees of LSA. Is it possible to have the LSA and LCA both at 106? It doesn't seem possible to me, but my cam card doesn't show LCA, it only says 'these specs are for cam installed at 106 intake center line'.

The idle seems fine to me, but I would have to be standing next to a 182 cam'd LT1 to really notice any difference.

So, does the 106 LSA give me more bottom end? Does that limit the upper rpm range?

Re: Correct me if I'm wrong ............
 

Ok, Marlin, I just got off the phone with both Crane and Comp Cams, and here is what I found out:

Crane Blueprint Cam (1970-1 LT-1):
Part# - 969551
Grind# - 3972182
Gross lift (int./ex.) - .459"/.485"
Duration (@ .050", int./ex.) - 242/254
LSA - 116
LCA - 110
Notes - 1 , 2

Comp Cam (your current cam):
Part# - 12-511-5
Grind# - CS 272 TLS-6
Gross lift (int./ex.) - .510"/.530"
Duration (@ .050", int./ex.) - 242/250
LSA - 106
LCA - 106
Notes - 1 , 2

Now, some observations. What jumps out at me first, and what I questioned above, was the LSA difference between the 2 cams. The original cam had an LSA of 116, which should have a little "lope" to the idle, yet still have plenty of vacuum. Your current cam, on the other hand, has an LSA of 106...this is extrememly tight, even for a race cam! The Comp unit should provide a VERY lopey idle, and would be poor in the vacuum department. I asked both Comp and Crane about that 106 LSA, and they both said "no way" for a street car, and that with that tight of an LSA that you would have little or no vacuum and it would be a dog on the low end. But, what confuses me is that you said the idle is fine and you have plenty of vacuum? The Comp unit is clearly directed at top end, which would be fine if you are looking to race on the skinnies, but it's not necessarily what you were after. The LCA of the Comp unit is advanced 4 degrees ahead of the original, which would help with the bottom end, and all of the other "minute" differences (lift, duration, LCA) would have small effects, but the difference in LSA is what has me confused...am I missing something here fellas? Oh, just curious...did you assemble the engine and put the cam in yourself? Not criticizing, just curious!