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.)
That cam is a copy replacement for the L-82 350 motor cam. (245HP)
Its the same lame GM cam that comes in the lame 350-290hp GM crate motor.
no power and no torque.
It was lame in 350's and is lame in your 327.
And changing to a 1.6 rocker will not fix that.
Your money is much better spent on a better more modern hyd cam and lifters.
Keep the 1.5 rockers. They are fine.
You will notice a big performance difference with a different well selected hi perf cam in your 327.
lobe lift x rocker arm ratio ='s lift at the valve.
1.50 VS 1.60 ratio multiply the valve lift by 1.0666
EG: .450 x 1.0666 ='s .4799
Crane Z-268-2 Crane #113521
Another nice choice
summit racing cam # SUM-1788
Here is a nice Howards hyd cam for your 327
All these will out perform the cam you got, reguardless of what rocker ratio you use.
cams have come a long way since 1968.
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?
All the cams I suggested idle at the same rpm as the cam you got.
They are all more powerfull and responsive in the same overall rpm range.
With the car , motor info you ahve now provided, I would use a smaller cam
than the cam you got now.
A lot more torque in the rpm range you will be using.
Now that I see the combo that cam is even more lame.
Use a cam with 208 to 218 @.050 intake duration
and 218 to 228 exhaust duration
The cam you got is very lazy in your car. (late intake closing point)
It was origionally designed for a 4 speed with 11:1 compression
This is probabily why you want to change things looking for more
keep the cam duration small for the OD transmission and 336 gears.
Here is the page on summit with all the SBC cams listed.
you can search thru that.
any of the cams within the duration group I outlined will
be a winner in your 327 w th700r4 trans .
Yes these short duration cams like a 1.6 rocker.
now you are cooking with gas. The cam you got is a real stinker.
here is a good example of the cam you wouls want to change to.
Comp cams Dual energy 265DEH-10 #12-208-2
COMP Cams 12-208-2 - COMP Cams Dual Energy Camshafts - Overview - SummitRacing.com
any cam with a similar .050" duration will be a winner.
all are way better than that stinker.
now your new heads can shine.
even this $54 summit "1103" cam is a good improvement . (this cam actually works very well and is a good match also likes 1.6 rockers)
Your 336 gears are very tame for the th700r4 trans. If you want more acceleration consider a gear swap (3.73-4.10)
now your overdrive is actually usefull Remember the OD knocks down the gear by 30%
you'd really like 4.10's in that car with the th700r4 trans. (2.87:1 cruise gear in OD)
what you got now is useless
3.36's and OD and a lame cam.
not suprised at all you want to make changes.
your 327 will be a lot more spunky.
non of the cams I suggested have a offensive idle at all.
Consider the camshaft, to the motor likened to the conductor of a orchestra.
Your cam is playing the wrong tune.
not reading from the same page of music as the rest of the motor.
you'd really like 3.73's in that car.
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 $$ on a new transmission and rear end, there will be no changes to these components in the near future.
My initial thought was to use my existing cam and lifters which were installed on my rebuilt 327 about 2 years ago. So far I put about 4K miles on the engine. I was going to change the heads and use roller rockers with new push rods but use the existing lifters and cam...However, it would appear that my cam is too lame...so..if I end up changing the cam, I will most definitely put in new lifters.
I always add a can of Cam prelube to evry oil change I make. It bumps up the oil zinc content (ZDDP) that's greatly reduced in mondern oils.. Specifically I use Lucas Break-in Additive.
Specifically I am after some better low end torque and better off the line response.)
After spending a ton of $$ on a new transmission and rear end, there will be no changes to these components in the near future.
But you are willing to dump another 1600
2K on cylinder heads that won;t make much difference untill you get
some gear in this car.
Your poor combo decisions are what is holding this car's performance back.
All this car needs is a gear change really. to make it do what you want.
thats much less money than new cylinder heads.
You can lead a horse to water but you cannot make it drink.
3.73's and one of the modern high torque cams I suggested will change the whole nature of this cars performance.
It will accelerate a lot better and The OD gear will be actually usefull.
All at a fraction of the price of new heads.
All the power gain of new heads will be at 4000++ rpm . (top end power)
You will never get ot use that with the gears you got in the car now. You can dump another $2000-$3000 in it
and it will still have snail acceleration untill you got it some gears.
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.
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