Little Mouse

Having owned four vehicles with 3.70 or 3.73 gearing you are at
3000 rpm quickly, really I think the comp mans recomendation
for your setup was the right one if you build it with decent comp, now if you had 3.08s yep you could stay under 3000 a lot more use a milder cam. Just my 02.

Scott Marzahl

A XE284 will be a total dog at 9.5:1 compression, the intake closes at 68 degrees and it has 240/246 degrees of duration! Not to mention the stock heads will not like the lift that cam has unless some machine work is done to add screw in studs and the spring area worked to allow that much lift without binding. IMHO, design for your objective of dependable, reliable weekend cruising. If you are want a big nasty cam, you need big compression to make it work.

AWilson

I appreciate the info. I only picked 9.5 CR because I know going too high can get you in trouble. Maybe it should be higher? I am trying to stay out of trouble but admittedly, I am scared to death of building a dog.

Most guys seem to want the performance first and the idle or street manners second.
I am the opposite. What I am trying to do is build a 383 that idles well, or compromise a little and say idles fairly well. Within that parameter, I want to get the most performance I can.
When I was a kid, I rode in many different muscle cars, stock and otherwise. Even the scarry ones idled well. Now, that may be mild to todays capabilitites, but for me what was scarry then will be scarry now.
Thats what I want.
But now that the parameters are restated how do I get there? I don't think what I am trying to do is difficult given these paramenters. There is a max performance for the street manners I want. I realize It will not be the overall MAX possible.

Little Mouse

Having driven a 71 Z/28 with just a 350 9.0 compression , M21
3.73 rear gears it was no dog with a 242 at .050 duration old
tech LT1 cam that came in it, nice thing about it pull up to the
pump put that lousy conoco cheapest grade gas ran just fine.
My 302 11.0 the high price gas The comp man Knowing
your engine will have poor air flowing factory heads that are
way to small for a 383 was trying to keep your engine from being
a complete dog in the mid range, with 3.70 gearing your car will
most likely be in the mid range a lot more then a 3.08 geared car.

Scott Marzahl

You can't directly compare a solid cam duration to a hydraulic cam with the given .050" numbers. Hydraulic durations are given at .050" lifter rise above the base circle, and you need to measure above the top of the clearance ramps for a mechanical lifter cam. Then you can compare the two durations, the LT-1 cam when converted is 231/239.

cardo0

Why do want to shop for a cam now? U won't know what the c.r. is until u have the pistons and u really can't choose pistons until u finish the head work and measure the camber vol.

IMHO u are the typical beginner (hey we are all begins just at different stages so do not take this personal) and are way ahead of yourself.:o

Once your head work is done we could help u with the pistons but thats kinda a long war off right now.

My advice to u is to order a camber vol measuring plexiglass plate and beaker for now.

cardo0

Matt Gruber

U won't know what your 2nd cam should be until u try your 1st.
SUM-k1105 224/234 $69 inc lifters!
Drive it a few months, then go bigger or smaller depending......

Scott Marzahl

I don't disagree but if you look at any Crower, Crane etc solid, they give you the durations at .050". For the LT-1 cam by Crane, they list the duration the same as you quoted, "242 at .050". Regardless, you can not compare the 242 duration for solid cam straight across to a hydraulic cam. This just further confuses the OP.

Little Mouse

Awilson 3.70s is mid range for gearing there not 3.08s that were considered good highway gearing before overdrives showed up
and there not 4.56s that are a good strip/street gearing, really
4.56s are not a street gear but people used to put up with them
on the street. If you go to mild on the cam the car will have a
gear bound feel, pick a cam that matches your mid range gearing
not race car radical but not ridiculous mild.

AWilson

I'm not buying anything right now. But I am trying to get a grip on if everything I want to do is feasible before I start. Once I have most all the answers, and I almost do, then I will start in a logical fashion. That way I minimize wasted time and money and get a good final product.
I appreciate your comments. I agree and disagree. Here is my thinking:

I think it was you who questioned the pistons and the need for the machine shop to have them. I think I agree with you about that. Originally I didn't agree with what you said last week because It still makes sense that the machine shop would want the pistons before they final hone so they can match them up. BUT, while driving home from work one day last week I started thinking. If CR is so critical, and pistons come in different heights from pin to top, and until it is decked I don't really know how much they have to take off, and the head work will change the chamber CC's, then how can I buy the pistons ahead of time with so many variables yet to be understood? HMMM, that Cardo0 has a point. So I need to ask more questions about this before the block goes out. To be safe I guess I do everthing but the bore and hone then buy pistons and then bore and hone.
Thats where I am at with that.

I am a beginner. But I am by no means typical. I don't take it personal so no problem. I bet I have learned and understand 2X more in the last few weeks than most do. I take great effort to read and learn first. The reality is a typical beginner will build up something based on dreams instead of reality, wishful thinking instead of facts. Partially because they are either all or some of the following: Are too excited and want to get started, cannot learn and understand all these topics, cannot afford to do the right thing. While I can be suceptible to all these also, I am aware of these things, so am doing everything I can to avoid it.
I knew nothing a few weeks ago. I know a little now, so it's working. The forum is my best friend and worst enemy. But overall I treasure it. So me, the unknowledgeable guy, has to weed through and decide what info is right and wrong. Odds are against me because of my lack of knowledge. I know that too so have to be even more carefull. But, there's a point where I will just have to hope I got it right and spend money and see what happens. That day is coming very soon!

The cam is interesting. But I know that I will create the CR I want by buying the right pistons to make it happen. Isn't that in the neighborhood of 9.5 because:
old steel heads
unleaded gas
I don't want to flirt with detonation troubles
want good street manners

I believe I have plenty of info from all the folks to make a decision. I just wish the noisy Comp cams Extreme Energy issue didn't come up.

I am already working on the beaker plexiglass thing. Snooping around at work for whats available. I fully understand I need to nail down those chamber sizes or it will be a guess as to CR.

So Cardo0, be patiend with me and keep responding. I don't know if I will take all or any of your advice for that matter but you come at it at a different angle or say things a little differently and I see value in it.

AWilson

This is actually an excellent point. Really how big of a decision is this? Cost is not a big deal really. Cams are under or around $150.
So can I change the cam with the engine in the car in say a day?
Maybe I just have to remove the radiator, timing chain? If so, so what! I have spent a lot more in time and money to learn things the hard way.

Yes/No?

dgruenke

When I cc'd my chambers, I did not want to spend big bucks for the fancy tube with petcock. So, I bought a piece of plexiglass from Home Depot, drilled a small hole in it, and set it on the chamber (with grease to help seal it. I then used a tool for injecting fluid into a turkey when you cook it (you heard right). It just looks like a typical syringe, but measures in cc's. Mine measured right at 64cc.

AWilson

This is my kinda thinking! Thanks!

Scott Marzahl

Yep, just go get a syringe at your local pharmacy or vetenarian/farm supply. Stock 291's should come in right around 64cc.

It sounds like you are thinking things through very well.

AWilson

I talked to Chris at Engle. He actually spent the time to talk to me. Good service from a small company. What else is new!

He thinks their EP-18/20HY .458/.468 216/226 112deg. is the way to go. 112 important to run vacuum and for idle. says it is very popular with hot rod guys, light cars.

Also said EP-43HYD. .471" 222deg. but go 112. He said dul pattern for Chevy SB is not required but can do it.
I told him what Scott said about blending EP-43 and EP-46. He liked that too.
Again I was impressed that he really discussed it with me and was very accomodating.
Anyone else have experience with them?

Great lead, thanks!!!

Scott Marzahl

I've used Engle cams for many years and as you found out, it is a small family buisness that wants to help their customers. I know several So Cal builders who only use Engle Cams. Traco Racing Engines used to use Engle cams, they were just down the road from each other. It's really a matter of preference, but I have never had a bad base circle runout with them like I've seen with CC.

That 18/20 is very popular as is their EP-22HYD 230 duration cam. Given the fact that you want a nice mannered cruiser targeted at 9.5:1, it will provide great throttle response and the manners you seem to be after.

I know a few guys who even run the GM "151" cam in their 383s and it does everything they want it to.

63mako

with the 112 LSA but I think with that cam @ 9.5 to 1 with iron heads your DCR will be too high. A 383 with 3.70 gears and 4 spd can handle a lot more duration than that and still pull good down low. Around .500 lift will work better with those low flowing heads too. Take a good look at the Lunati link I posted.

AWilson

I checked it out and heres the Lunati specs:

Duration at 050 inch Lift: 227 int./233 exh.
Valve Lift with Factory Rocker Arm Ratio: 0.489 int./0.504 exh. lift
Lobe Separation (degrees): 110 Power range starts at 1800

Heres the Engle:
Engle EP-22HYD
Duration at 050 230/230 Lift .480 LSA 110 but I am sure they will grind a 112. Power range starts at 1800

Extremely similar with the Lunati being a little hotter. Also very close to the Comp XE268H but without the controversy.

Hmmmm, I think I like these overall,,,,,,,today.

Will Lunati grind me a 112? Because I need vacuum for my headlights and it helps the idle a bit but mid range can suffer slightly. (According to Lingefelter)

AWilson

Scott,
I appreciate your input. Just to be clear I am not set on the 9.5. I just thought thats a good target to keep me out of trouble. If it is too conservative let me know but some say 9.0 is the limit?

AWilson

So nice mannered cruiser means? I want to jump in the car for a milk and bread run for the wife on a nice night without having this monster out in front huffing and puffing. But if I want to stomp the pedal and run through the gears for a few seconds once or twice along the way,,,,I WANT IT TO GOOO!