My 327 SBC was built with the following cam: ES1095M
Here is the description:
62-69 Stage 2 high performance. Use hydraulic flat followers. .050" Duration-224/224; Cam Lift-.300/.307; Lobe Center-114/114. Use high performance spring kit p/n VSA3 or ERV943 springs. 1.700" installed height. Coil bind at 1.160".
When I use this cam in combination with 1.5 ratio rockers, I get a maximum lift valve of 450/461..
When suppliers advertise the lift of a cam, are they using 1.5 x the actual lobe lift? or the lift of the actual lobe?
I am intending to use this same cam with a set of 1.6 ratio rocker which will give me a lift of 480/491. The springs I will be using allow a maximum lift of .550. Am I getting too close to the max or is this considered well within a safe range?
Cam lift is lobe lift. Valve lift would be with rockers installed. You should have got a card with that cam with both cam and valve lift on it. Springs should be ok. Dont forget your 1.3 breakin rockers or pull the inner springs for breakin.(along with your breakin lube.)
Thanks for the candid input. I will certainly look at replacing the cam.
All the cams that you suggested are marked as idle starting at 1500 through 5500 (roughly). What exactly does this mean?
One thing I do want to avoid is rough idle and/or having to raise the idle well over my present 800 RPM to keep the car running.
I do appreciate your input, especially since I know so little about the subject. But maybe it would help if I gave you a little more detail aboiut the car and what I hope to accomplish.
It is a '68 Camaro Convertible with a '68 327 motor - bored 40 over.
Has a Edelbrock Perfromer Intake(not RMP, not AIR Gap)
Automatic Transmission: 700r4 with a 2200 (or 2400 can't remember) stall
10 bolt Eaton Posi with 3.36 gears
Doug Thorley Tri-Y headers (1 5/8" primaries)
600 CFM Holley with vac secondaries
Stock rad, stock waterpump
High output oil pump.
Will be changing stock heads - double hump 291 (with the smaller valves) to:
AFR - 916 (with 2.02 valves and lighter springs to match flat tappet cam, .550 max spring lift)
Airflow Research (AFR) 0916 - AFR 180cc SBC Eliminator Street Heads - Overview - SummitRacing.com
Scorpion 1.6 roller rockers
My objective is to maintain a well behaved, strictly "street" car that does NOT have an offensive idle. At the same time, I would like a litte more perfromance than I have today. (Specifically I am after some better low end torque and better off the line response.)
BTW I installed Hotchkis Frame connectors to stiffen the body.
With that in mind, would these still be the recommended cam?
To answer your question specifically:
"All the cams that you suggested are marked as idle starting at 1500 through 5500 (roughly). What exactly does this mean?"
This is the general powerband of the cam (not the idle RPM's). Generally the cam makers are going to rate this against the standard 350 ci. So on your 327 these values will shift to a higher RPM range (and 383 strokers and 400 SBC will shift lower).
Also, is that cam you initially mentioned a used cam? I would never trust a used flat tappet cam. Even if you kept the lifters sorted and mated them back on the same cam lobes, you are looking at a 50/50 chance of wiping the lobes on flat tappet cam. And if you didn't keep track of your old lifters and what bores they went to, forget it, game over. Also when you buy the a new flat tappet cam you must get new lifters too. Never re-use your old ones! I would suggest getting the springs too, but you are getting a set of pre-assembled heads, hopefully the springs are close enough to the cam makers spec.
Make sure you read up and study the proper way to break in a flat tappet cam. It is absolutely critical you follow the correct procedure. It is also important to chose your normal engine oil to match the demands of a flat tappet cam. Oil these days aint what it used to be back in the day.
Thanks for the response folks.
I must admit this is is a bit overwhelming (for me) trying to sort out all this pieces. I'm sure for the experienced guys its a walk in the park....but not for me.
First, let me clarify some things. After spending a ton of $$ on a new transmission and rear end, there will be no changes to these components in the near future.
My initial thought was to use my existing cam and lifters which were installed on my rebuilt 327 about 2 years ago. So far I put about 4K miles on the engine. I was going to change the heads and use roller rockers with new push rods but use the existing lifters and cam...However, it would appear that my cam is too lame...so..if I end up changing the cam, I will most definitely put in new lifters.
I always add a can of Cam prelube to evry oil change I make. It bumps up the oil zinc content (ZDDP) that's greatly reduced in mondern oils.. Specifically I use Lucas Break-in Additive.
To step in here for a moment, listen to fbird, he is spot on refering to the lame cam and especially the gear ratio, why not step back and listen to those who "know"and not waste time and money, it will be a whole different car when done and you will be thankful for many many days to come.:thumbup:
I don't understand. The OP has spent a lot of money on a rear end that is sooooooo not optimal for the application, a crappy cam in a small cube motor, doesn't want to listen to reason and is now stating that he wants to spend MORE money on heads and useless roller rockers, and is looking for more performance. Makes absolutely NO sense. The heads are only as good as the rest of the combination. So, putting new heads on a crappy motor with a terrible O.D./rear end combo, added to a set of rockers is going to give you near ZERO performance upgrade and is nothing more than pissing more money out the window.
These are the questions that should have been asked BEFORE you spent money on a crap cam, wrong rear end and O.D. trans. The BEST preformance upgrade for the money is going to be a cam and lfter kit AND some rear end gears. Period. If you want a bit more then get some heads. If you don't like the answers you get you shouldn't ask the questions. It's really that simple.
A lot of people don't want gears because they get worried about buzzing down the interstate near 3,000 rpm. A 327 well built will buzz along happily at 3,000 rpm all day long. It also puts you closer to your tq peak so you'll be able to use the power you already have. Gears are probably the single most significant change you can make for performance, except maybe boosting the engine. You won't believe the difference. Build your engine to run between 0-5500 rpm, the gear it to put you in the middle of that power band when you cruise, it makes for one FUN street machine that is so easy and reliable my grandma could drive it.
Wow... I was almost certain that this was a discussion forum and not a lecture hall.
Greg, I don't understand what you don't understand. I'm certain not everyone on this group is an expert that did it right from day one...if they were, they probably wouldn't really need this forum.
Pretty sure that most of us learn by mistakes. I guess its possible that some us of were born knowing all this stuff...but not me. (I'm feeling so deprived.)
I haven't figurd out a way to go back and change things in the past...so "asking the questions before" is pretty much a pointless endeavor. Oh and by the way, last time I checked, the forum doesn't restrict us to asking questions that we will only like the answers to. I'm pretty sure we can ask questions were we won't like the answers....we should check the rules. Lets ask the administrator....
Administrator: Is it ok if I ask a question that I won't like the answer to? or can I only ask questions that will make me happy?
Oh and by the way...I almost forgot....that's right..this is a hobby for me. I did not wake up one day and decided to plan and build the best and the fastest ..and the least crappy. I just wanted a car to enjoy and maybe get a bit better performance. I haven't been planning this for months or years. I didn't adjust the mortgage so I can finance my ride accordingly...I didn't abstain from my normal life to plan my car.....sorry to disappoint you.
You guys must have some pretty impressive cars ..cause it seems everything else is lame, usless or crappy. Does anyone else on this forum have useless, crappy and lame cars? I think maybe there are one or two..or maybe I'm the only one.. Us guys with crappy cars should just leave (I sure felt like it after this thread) ..since we are probably just wasting our time and money here.
Here's a good idea: Lets stick to the constructive technical stuff and leave all the descriptive, degrading adjectives out. Here's another one: ...lets answer the question to the best of our ability, point out mistakes and oh..yeah..lets act our age...(I'm 55 and lost tolerance for arrogance and BS a long time ago).
Thank you! for pointing out the errors I have made. I will seriously consider all the valuable technical information F-bird and everyone has taken the time to post. I will promptly dump out the rest of the useless, (my turn)...crappy and lame comments and descriptions on this thread.
And, what I don't understand is why someone would ask for recommendations and then argue about the perfect and correct advice.
Fwiw this is a hobby for 90% of us, and as far as arrogance goes I'm the most arrogant one in this thread, and many on this forum will testify to that. That being said to make the same difference gears would you'll need to pick up a little over 10% torque at the same rpm you cruise at. That'll be damn hard to do with your POS cam. Swapping the cam and heads can do that, but will cost three times as much as gears. Id do gears and cam and maybe heads down the road. That's not arrogance its 3rd grade math.
Lets not fight about anything and get back to the discussions.
As AP pointed out, I have always been concerned about putting in ratios like 3.73 in fear of having too high of an idle at highway speeds. Also, we like to use the car when doing vacations and such...so we opted for the 3.36 to get the benefits of extended highway cruising. Hard to get the best of both worlds.
What about a reasonable compromise like 3.55?? (Its available for my rear rear axle).
WRT to the Cam..
The Summit CAM is reasonably priced and affordable especially as a kit (under $100 bucks including lifters)
Summit Racing SUM-K1103 - Summit Racing® Cam and Lifter Kits - Overview - SummitRacing.com
Here is another one that I believe is very similar:
Isky Racing Cams 201264-27112 - Isky Hydraulic Flat Tappet Camshafts - Overview - SummitRacing.com
I have to wonder why the Summit kit..which looks like a very useable product (and fits part of the recipe F-Bird gave) costs a third or half the price of the other cams.
We are only trying to help, but it does mean changing things "again" and more money but the suggestions will work in this case. Believe me I have been building hotrods of all types for 30 years and did I make a lot of mistakes on my own stuff that cost too much for many years, still learning and listening too. good luck, do the gears first and the current cam will work better, not great but better then change cam as funds allow. later man.
Swap cams, swap gears, and leave the rest ALONE for now. Don't get too far ahead of yourself. Id set your cruise rpms for about 2500 or 2600.
4.30s would be a hair too much around here as the interstates are 70-75mph traffic. 4.10s would be about right though.
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