Cam selection?

[a6t9vette]

Thinking to this winters project, cleaning up the engine compartment, etc., im planning on doing an intake swap, and have got to thinking hell while im in there might as well do the cam. But to be honest I know nothing about cam selection. Im obviously looking for some performace gain but dont want to go crazy since im not really diving into the heads, etc.

So some info: 383, all stock except carb; but plan to upgrade intake (probably to Edelbrock Performer for clearance reasons), and change to Electronic Ignition. Has a 600cfm Edelbrock (1406 carb currenty), 727 trans (assume stock torque converter), 3.23 rear (although I hope to swap to 3.55 or 3.73 over the winter as well), no P/S or P/B so vaccume isnt a big concern.

Im hoping someone has a similar set up and can recommend a cam, or at least point me in the right direction.

Bob

 

[ACME A12]

Mr. McGowan lives for these questions...I think he might be on Comp Cams' payroll...or at least has a ton of their stock...I'm sure you'll be hearing from him shortly... :lmao:

:jester:
ACME

 

[mcmopar]

Mr. McGowan lives for these questions...I think he might be on Comp Cams' payroll...or at least has a ton of their stock...I'm sure you'll be hearing from him shortly... :lmao:

:jester:
ACME

Ah grasshopper when you can grab the lifter from my hand you will be ready to walk with the big stick!
I definitely should be on Comp's payroll seeing how many times I recommend their products! And no - I don't own stocks of ANY kind! Much too risky these days.

Ray is correct. I do love to recommend to people how to spend their hard earned lucre!
Bob - one thing you did not mentioned is: does the car have headers and if not are you contemplating adding them? This will make a difference.

If stock manifolds are going to be utilized I'd recommend ( :rimshot: :rimshot: :rimshot this Comp grind:
http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=706&sb=2 and accompanying recommended accoutrements ( ). Even though the advertised timings are slightly smaller than the stock cam, the timing at .050" lift along with the newer lobe design utilizing the fast ramp technology should give you a better responding cam - especially with the Performer (not RPM) intake and the existing carb. Seat of the pants response should be a lot better than stock and this cam won't kill your low rpm vacuum.

If you are going to use headers or at least a 2.5" dia. system with some good free flowing mufflers I'd go the next step up and get this one:
http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=707&sb=2 and the recommended lifters, springs, retainers, et al. On thing to keep in mind is that you may need to have the tops of the valve guides cut down. Contact Comp's tech line to verify this. http://www.compcams.com/contact/default.asp.
A couple of guys on here have this cam and it sounds nice at idle. With 224/230 duration at .050" lift and .477"/.480" lift it should fit with stock pistons with no clearance problems and still leave a decent amount of vacuum at idle. Going any larger than this cam will require a new torque converter (2200 stall minimum), headers and a bigger carb. Larger is not necessarily better when it comes to camshaft selection. You want all your components to work together. If you are planning on keeping your setup on the mild side then either one of these cams should do very nicely.

For a car with stock exhaust manifolds its usually better to run a "split pattern" cam - as those above - with different durations between intake and exhaust. It seems to help the engine run better with a longer exhaust duration which helps evacuate the exhaust gasses better with the restrictive stock manifolds.

One other cam I'd be highly interested in - especially with a near stock setup would be this Comp number: http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=720&sb=2.
Its a modern version of the factory HP cam with more duration at .050" lift, slightly more lift than stock and fast ramp technology which means the valves are being opened faster and held open at max. lift longer than the stocker, thus producing more power. I doubt very highly that you'd need to cut down the valve guides but check with Comp anyway. This would be a very streetable cam and would probably produce decent mileage (as compared to the other cams) as well. Plus, you wouldn't have to make any other real changes to your combo as your present torque converter and 3.23 gears would work just fine ( as would 3.55's if you decide to upgrade) and the Performer intake and your present carb would work perfectly - especially with stock manifolds and exhaust piping. If I were building a mild street engine for cruising enjoyment I'd go with this one.

 

[69rrvert]

I am running the Comp XE-268-H cam in my 383 with pretty much the same setup as you. The motor has original heads and intake with a set of forged flat top pistons and original exhaust manifolds. I am running a Edlebrock 1406 carb with the Mopar electronic ignition. Stock 727 tranny with stock converter and 3.23:1 gears. The car runs pretty good if you ask me and it has a nice idle as well. It will not run the the Z06 Vette but I still enjoy just cruising around. Here are a few videos of the car. Hopefully the links with work. Thanks - Steven

http://s50.photobucket.com/albums/f328/ ... 0_4221.flv

http://s50.photobucket.com/albums/f328/ ... 0_0436.flv

 

[Roadcuda]

I am running the Comp XE-268-H cam in my 383 with pretty much the same setup as you. The motor has original heads and intake with a set of forged flat top pistons and original exhaust manifolds. I am running a Edlebrock 1406 carb with the Mopar electronic ignition. Stock 727 tranny with stock converter and 3.23:1 gears. The car runs pretty good if you ask me and it has a nice idle as well. It will not run the the Z06 Vette but I still enjoy just cruising around. Here are a few videos of the car. Hopefully the links with work. Thanks - Steven

http://s50.photobucket.com/albums/f328/ ... 0_4221.flv

http://s50.photobucket.com/albums/f328/ ... 0_0436.flv

Thanks for sharing that Steve! Your car sounds great! You're lucky to have room like to play when you want. There is just was too much traffic around where I live to do that and not worry about it. About the only place I can get away with cleaning out the secondaries is when I merge with traffic on the highway. After all, you have to do something to get up to speed and blend in! :devil:

 

[ACME A12]

Nice videos Steven!

Thanks for sharing! Great looking, sounding, and running RR!!! Sounds like you have a 22-point harness to buckle into when you get in that thing...

:jester:
ACME

 

[A12]

When somebody uses the term "Hemi grind" what is meant by that and does Comp Cams have something like that or would they special make something like that for a 383? Thanks.


MikeR

 

[69rrvert]

Nice videos Steven!

Sounds like you have a 22-point harness to buckle into when you get in that thing...

:jester:
ACME

Actually, I was having a hard time getting the camera to stay put. Just for grins and giggles, here are a few more videos. Thanks, Steven

The black/green truck is a friend of mine. Yes, it has a Hemi in it.

http://s50.photobucket.com/albums/f328/ ... 0_4220.flv

http://s50.photobucket.com/albums/f328/ ... 0_5776.flv

http://s50.photobucket.com/albums/f328/ ... 0_2338.flv

 

[ACME A12]

When somebody uses the term "Hemi grind" what is meant by that and does Comp Cams have something like that or would they special make something like that for a 383? Thanks.


MikeR

Hemi grind just means the equivilant of a stock Hemi camshaft...

Lift: .467" Int, .473" Exh, Duration: 276 deg (1966-1967 - Solid)
Lift: .490" Int, .481" Exh, DurationL 284 deg (1970-1971 - Hydraulic)

Comp does not offer a direct replacement to the best of my knowledge. They have a Nostalgia Plus line that emulates the old factory hot-rod cams, but I don't think they have a "Hemi Grind" per se. Crane had a line of blueprinted factory muscle car cams...but, well, we all know what happened to them... Not sure who has one these days...if anyone...and even if Mopar Performance offers one, I wouldn't trust their qualtity control enough to stab one of their bumpsticks into ANYTHING I build...I personally got one that was improperly ground and have read and heard many stories of others that suffered the same woes...it's not like it was in the seventies when Racer Brown was their camshaft guy...

Ray

 

[Hoosier Bird]

Great videos............ :yesnod:

 

[a6t9vette]

Thanks for the great reply guys. Steven good videos, give a great idea of what my car should sound like

To anwser my other set up questions, im running stock exhaust manifolds, into a 2 1/2 TTI system with H-Pipe


From reading up on the XE262H installation notes it reads:
Stock springs cannot be used.
Includes special shafts & spacers.
Special 10º locks, 1/2 2 groove, 1/2 set 4 groove. Single groove use part #612-16.
Pre 1968 use 824-16 lifters.
Adjustable valve train required.
Requires machining on cylinder heads.

I have a few more questions about this:
1) I guess since I cant use the stock springs that now this job got a little more indepth since I have to pull the heads (not really a question)
2)Adjustable valve train required, I assume this means I have to change the rockers?
3) This one scares me the most, what is machining on the heads is required?

I was really hoping to find a drop in replacement, but I guess that might not be possible....? Im mechanically inclined (hell im a Mechanical Engineer) but never dove into an engine with anything other than bolt ons....

 

[69hemibeep]

Steven. Acme thought you had a 22 point harness, I thought you were eating potato chips :lmao: Thanks for the videos

 

[mcmopar]

Thanks for the great reply guys. Steven good videos, give a great idea of what my car should sound like

To anwser my other set up questions, im running stock exhaust manifolds, into a 2 1/2 TTI system with H-Pipe


From reading up on the XE262H installation notes it reads:
Stock springs cannot be used.
Includes special shafts & spacers.
Special 10º locks, 1/2 2 groove, 1/2 set 4 groove. Single groove use part #612-16.
Pre 1968 use 824-16 lifters.
Adjustable valve train required.
Requires machining on cylinder heads.

I have a few more questions about this:
1) I guess since I cant use the stock springs that now this job got a little more indepth since I have to pull the heads (not really a question)
2)Adjustable valve train required, I assume this means I have to change the rockers?
3) This one scares me the most, what is machining on the heads is required?

I was really hoping to find a drop in replacement, but I guess that might not be possible....? Im mechanically inclined (hell im a Mechanical Engineer) but never dove into an engine with anything other than bolt ons....

You need to read the entire page. Those notes you referenced indicate special conditions in reference to certain recommended parts. If you look at the valve springs you'll see a part #911-16 that has no note attached. That means you can run these springs without machining the head.
Since the stock valve springs are too weak for this cam you need to run these springs to keep from floating the valves.
If you use the #925-16 springs then you WILL have to have the valve guide tops machined down and run Teflon oil seals. That's the extent of the machining they are referring to.

You can swap valve springs with the heads on the engine by using either a compressor and compressed air fitting that fits into the spark plug hole to pump compressed air into the cylinder to hold the valves in place or by filling the cylinder with a small diameter rope and bringing the piston up until it stops. This will keep the valves in place while you remove the springs. This is decidedly low tech but works just fine.

You can use your stock rockers with this cam - Mopar Muscle used the stock rockers with their XE285HL-10 (241-247/.545" lift) cam and had no problems. If you stay with stock rockers I would recommend a new set of MP hydraulic rockers because they are meatier than than the old stockers in the pushrod ball/cup area. Your old rockers may not hold up with the increased valve spring pressures and you could puncture a rocker with a pushrod. Not fun. Basically the new MP units are the ones that Ma Mopar used with the 6 BBL engines. See below for adjustable rocker arm conditions.

That bit about the special 10 degree locks is only applicable if you run the #627-16 valve locks. If you just need a single groove lock then the part to use is #612-16. Personally, I'd grab a new set of stock retainers and locks and be done with it. They can be had at NAPA or your nearest Mopar Performance parts outlet.

If your engine is a pre-1968 model then you need the #824-16 lifters. Otherwise you need to use part #822-16 lifters. If you use the #867-16 lifters you will need an adjustable valvetrain. Otherwise you can use your stock rocker arms and pushrods. If you decide to buy their #1321-16 rocker arms then they include special shafts and spacers.

If you need help in spec'ing all the parts you'll need I'll be happy to help.
Don't get spooked by those notes - as I said, they only are for certain situations. You can run this cam along with the #911-16 springs, #822-16 lifters and #612-16 locks with your stock rocker arms and pushrods and you won't need to do any kind of machining to your heads, nor will you have to remove them, although its not a bad idea to get a freshened up valve job while you are in there. If taking the heads off is not in the plan its no problem to swap the cam, lifters, springs, retainers and locks.

 

[a6t9vette]

Thanks for walking me though this I really appricate it....

So if im doing my reading correct it looks like either of the first two cams you recommended would require the same parts, etc. Im leaning more to the XE268H now, because it seems like it will give me a little room to grow should I want to do some more work in the future.... Although I guess I do need to confirm with Comp Cams if the valve guides need to be cut done. I would have thought a note to this effect would have appeared on the web site.

As far as a parts list I would appriciate your help, im on a budget so trying to do this on the inexpensive side, but on the same note dont want to have to pay to do it again in a year. If I am misreading this and the XE262H requires a lot less new parts, etc please let me know as I may then decide to go that route.

Thanks again,
Bob

 

[mcmopar]

No problem, Bob. I'll get on the horn to Comp's tech line and make sure those 911-16 springs won't require you to cut down the valve guides. I'll then check on some pricing for you. I like to use Mancini Racing but I'll check around with Summit and some others too.

 

[a6t9vette]

Thanks. Although there is no need for you to shop around for the best price, I dont want to tie you down to have to do that, if I have a list of all the parts I need I can check prices, etc.

Thanks again....

On a side note, I have been shopping around for an intake as well, and had pretty much decided on a Edelbrock Performer (not RPM), due to hood clearance. With this cam selection should I really be looking for a Torquer (which I belive will clear as well) or other?

 

[mcmopar]

Hey bud
I just sent Comp a tech question relating to the XE262H so I hope to hear from them soon.

In regards to your intake question, The Torker will make a bit more power than the Performer and should be more fuel efficient as well. I had great success running a Torker and mild cam along with a small Holley carb on a 440 in my 1st road runner back in the late 70's-early '80's. The Torker makes a good bit of low end grunt as well and gives good throttle response.

The only problem with the Torker is that its kind of a pain to install. Getting 4 of the bolts in is problematic because the runners are in the way. You may need to go with a slightly shorter bolt for the holes that are located inside the runner footprint and put them in the holes before placing the intake down. You'll then have to start them in while holding the intake in place just above the heads. Like I said - it takes a little patience. You will also only be able to tighten down the 4 bolts to the inside of the runners with an open end 9/16" wrench as neither a socket or box end will fit on the bolt heads - and even then its slow going. The intake is a good one and worth the effort but be forewarned - it isn't a simple bolt on. It will take some time to get it bolted down.

 

[a6t9vette]

Great. Thanks again I appreciate it...

Bob

 

[mcmopar]

Here is what Comp wrote back:
"Yeah the 911-16 spring is a single spring and does not require machining on the head to fit it. The only thing that might come up is the stock rockers are fine but you need to look at the preload that they put on the lifter. Preload should be around .020-.040 preload. If it is not in this range then you will have to change pushrod length to get it in that range. I don't think you will have to do that but it is something to check."

So you can run these springs without the need for machining the heads. You might also consider the Mopar Performance #312-P3690933 spring. Its a single spring for cams up to .500" lift so they should easily handle the 262H cam. You won't have to do any head work with these either.

 

[a6t9vette]

Would it be safe to assume that since the XE268H calls for the same Spring that, I should be able to use either it or the 262 with the same hardware, etc? I still really havent decided which way I want to go, I guess it will come done to parts needed and cost, etc....