I am looking to order a new cam and intake from summit. I am going from a Vic Jr to an air-gap to bring my RPMs down. It is a street car. And I am looking to get a smaller cam. The one I have now is huge for my motor.

Here are the specs.



I want to go a step lower than this to bring my max TQ levels down to where I can use them. It is purely a street car. I want to drive this thing every day 3 seasons out of the year.

I know I am going to loose a little top end HP, but I just really wanna make a TQ monster instead of what it is now. A high revving highway puller.

it makes 344 RWHP now and similar TQ.

I have an idea of what to get, but want some input from you guys. Thanks. -Dennis

 

Stick with Crane, they seem to have better quality than Comp these days. Isky is also GREAT, but you are going to pay more.

The last comp cam set I bought had metal all down in the lifters. I sent it back to Jegs for a full refund. No way in hell I was going to install that, or even try to clean it up after spending the money I did. I just sent those POS's back and bought a Crane cam. The Crane cam runs quieter than my last comp cam and seems to run very well. Seems Crane makes the cams for ALOT of the other smaller companies as well. Summit, GMPP, and Blue Racer are all made by Crane.

 

Thanks. i will look up crane cams for this next run.

Now if I could just narrow down the search some more.

I am running a hydrolic roller right now and wanna stay that way for this street motor. That cuts a lot of stuff out.

Then I know the flow #s for my heads so I know that makes a difference. (I am a total newbie when it comes to cams, This will be my first cam that was not a part of a package so bear with me)

Here are the flow #s straight from trickflow.

http://www.trickflow.com/product/che...75_airflow.asp

My motor is a 386... Slightly more bored out 383.

Not 100% how big that makes my bore size. But looking at those charts, Looks like I don't need a cam that lift much more than .550 or so.

Selection narrows a bit more.

Now I guess I need to look at duration. I have too much overlap due to duration. I hear I should go with something in the 245 range or something like that. Kinda lost here.

I will stop here and let people input. Thanks so far.

 

Take a look at the Crower 00468LM. 277°/286° adv., 225°/232° @ .050", .535"/.550", 110°.

 

When you are cruising on the hyway in top gear a the speed you like to cruise at, what is the rpm?

 

Whoa whoa whoa....

Still a newbie here. haha.

I know my heads don't flow much more past .5 so I am clear there, but going from what I have in the pic (246/254) to 225°/232° @ .050" <--- That just seems small. I have been trying to read around but I dunno. Fill me in on your reasoning for suggesting that.

Not saying that I don't like the suggestion. I love all the help I can get, just want to know some reasons why so I know that what you are thinking is what I am thinking, in terms of what I want this car to act like.

It has a T-56, and 4.11s in a moser 12 bolt. Bottom end is all forged with Al heads.

I am trying to make 400 Rear wheel TQ.

Please any and all advice and/or stuff I should know about swapping my cam.
----------
1500

65 MPH in 6th gear the car is at 1500 RPM.

At 100 I am at 2300 RPM.

That 6th gear really really drops it down.

 

Since I have no idea what I am talking about with cams, I am just going to post up ideas of what a nice came for my car might be.

TFS-31402001

This is the first step down from what i have in the car now.

The cam in the car now says it will have a rough idle, this is true, haha. Also says makes great power from 3200-6800. thats really high. I want from like 2000 to 6000. Or something like that.

here is where I am looking.

I think trickflow gets their cams from crane

http://www.trickflow.com/product/cam...cams_chevy.asp

Look at the bottom of my pic.

 

The cam in the car now says it will have a rough idle, this is true, haha. Also says makes great power from 3200-6800. thats really high. I want from like 2000 to 6000. Or something like that.


The GM "hot cam" or something very similar, would be right for you.
218-228 @.050 .525" w/1.6:1 rockers 112LSA

here is a similar crane hyd roller cam
http://www.cranecams.com/?show=brows...tType=camshaft

Since we drive our cars a lot more than we race them the subjective
drivability ("feel") at part throttle is very very important. What has happened in your case gotten tired of the big cam is very common. Nothng wrong with that. its not enjoyable to drive around if its just too radical for your usually driving style and conditions.
Like cruisng at 65MPH at 1500rpm in high gear.

A smaller yet still powerfull cam like the Hot Cam will still deliver the goods yet is a lot more enjoyable to "drive" on a daily basis.

This cam or someting real near it combined with a Dual plane hi rise manifold will really kik up the midrange torque and part throttle cruising drivability a lot.

 

2000-6000 sounds like that crower mentioned above would work nicely.

I think the hot cam (218/228) might be a bit on the small side in a stroker motor.
I have 224/230 (albeit flat tappet) in a 350 and it's 1500-5500RPM or so. A bit tame for your uses.
----------
Dennis, you've started a few threads, and I think i'm in the wrong one, but anyway;
You say you have a vacuum can, but it's not up to snuff. Can you elaborate? Do you get a few good pumps of brakes before it dies off or...?

 

Yeah, Well i mean I dunno. It feels the same with 15 as it does with 9 so I guess so. I can get like 2.5 good pumps. So I guess 2, haha. Then it gets really hard. If the car is on I need to rev it up a bit. Then I have good feel again.

The can doesn't make me have more vacuum it just makes me have more pumps of my low vacuum. Thats all. I think I might need actually higher vacuum, not just more of the same.

This is all kinda a mute point since I will be changing cams and intake soon to try and make the car more drivable. I am sure I will be pulling more vacuum then.



----------------------------------------------------

Back to cams,

Sounds like that "hot cam" is def too small.
Checked out that cam that was linked. Looks good. Is that duration too little at 222 and 230?

Would the trickflow cam fit me better?

--------------------------------
Fair idle, broad midrange power, 2,800-6,200 rpm powerband. 2,500-3,000 rpm stall converter.
Compression: 9.5:1 minimum


230°/234°

.352/.359

.528/.539

110°

-----------------------------

It moves the RPM up a bit, but I am not too worried about that. It should be able to rev fast.

Anyways, I also don't want to get stuck right outta my power band. I really want it to be strong down low, but I still want to make good power.


Ugh.... so many different cams to choose from!!!!!!!!

 

Well your vacuum fluctuates as you drive. Engine braking gives you BUCKETS of vacuum. You get 9" when cruising? Probably 20" or so when hard engine braking, that's the beauty of the stickshift.

If you downshifted everytime you needed to brake then you'd always have plenty of vacuum for brakes. The vacuum can is for the times that you need emergency vacuum and don't have time to downshift, so you'll get your 1 or two pumps in. If you put your car in neutral everytime you brake then you'd need a big can (or a smaller cam, which sounds the way you're going).

I'm just making sure you're not downgrading your cam (and cars performance) solely for the better brakes. If you're also doing it for mileage and ease of driving, then give'r torque. (haha, literally I guess).

 

I'm going by over 35 year of experience of a lot of different cams used in different motors and different cars over the years.
Don't let the numbers sway ya "thats too small" etc. the actual in the car power is going to be not that much different. The bigger cam wil make a higher peak (most times) but a smaller cam always "drives better" overall and many times the car will et quicker at the track. (higher average torque)
All these cams will still pull strong to 6000++rpm.
if you used say the crane cam I suggested with a 1.6 intake rocker the net valve lift will be the same as now. I'd use a split 1.6/1.5 rocker set with this one.
You can get all the top end power you have now, back again and then some by improving the breatheing heads, exhaust etc even with a milder cam. You can go very fast with either the crane or the hot cam. the manifold vacuum will be a lot higher in either case.

have you tested your car at the drags?

 

Nope, I have not had a chance.

If you have a ton of experience I will def be extracting as much info from you s possible.

I drive this car to work everyday. I put 3000+ miles on her in the summer. I like to drive her hard, but there are a lot of cops around here so I keep it pretty take most of the time.

I am not changing the cam for the brakes, I am changing the cam cuz it is a high rev cam and not making the low end that I want.

I know I can allways just get a pump. I would rather not have to though if I am already going to make agood amount of vacuum with no pump. Oh and YES, I do down shift when I need to brake. And yeah, I have like 19" when under hard engine braking . Its great and that strange hangup problem pretty much never happens when I am doing that. Only when I have low vacuum.

Anyways, I am going to get an air-gap at the same time to compliment the cam and swap them both at the same time. The single plane wants to be on something that revs high like the cam I have now. The air-gap is a nice dual plane that should increase divability. i also wanna get it i that dark chrome finish that edelbrock has. Looks killer.

With only about 400-600 bucks in this transoformation I thin the car will become a lot more fun to drive.

 

Ditto on the Comp stuff...

Same type of issues with the cam. The journals are all raked up. I like the grind so Im going to file a warrantee claim and get another one from Comp. Hopefully this one wont have the journals ground with 40 grit sand paper.

Isky does seem to be alot better

 

custom grind XFI grind from comp cams

236/242 on a 113 lsa. that will be a kick *** cam in a 383

otherwise the next size down is a 230/236. that also will work great and be a bit more street friendly than above. Just keep the lift with 1.6 rockers.

 

One "step" in cam size isn't a whole lot. In most mfrs product lines, that's about 8-10°.

A 230° hyd roller is ALOT of cam for a street car. IMO that's about as far as you'd want to go, especially with as much trouble and complaints and general dissatisfaction as you've gone through with this poroject. And given the way that cams tend to be, it's always better to err a step on the small side, than on the large side. Like F-bird said, the smaller cam will give you better driveability, better leave especially on the street, and ALOT less trouble in a general overall sort of way (fewer broken parts, easier to tune for weather changes, better gas mileage, etc. etc. etc.).

I'd strongly suggest seriously considering backing it down to a good hard-running street cam level, and not go for broke so much. I think you'll likely make your 400 ft-lbs of wheel torque with the one I posted, probably with the one he posted as well; and it will even be at an RPM where you can actually USE it. Which is more important than some arbitrarily high number.

 

i agree with Sofaking's post completely. For all the reasons he stated. Notice we are very close on our best picks for a new cam.

 

True, good advice sofakingdom.


So you really think that the cam you posted is the best thing for me to go with?


Does everyone else feel that way?

I want to stay away from the custom grinds just due to $$$.

They are quite a bit more. I guess I will need to pick up a set of rockers too. Not too big a deal. I have 1.5s now.


So this is the first in line cam:
Crower 00468LM. 277°/286° adv., 225°/232° @ .050", .535"/.550", 110°.


Does crane make something similar? People seem to love them. And my cam I have now is from them. Would be nice to keep in the same company since mine has been good to me.

I have my shopping cart filling up over on summit. Once you guys help me find the right cam, BAM I am ordering.

 

I dont care for the 220 range myself but... thats just personal opinion.

You already found out the current cam is way too much. Way as in at least 10, 15 degrees, maybe more. I suppose the final choice is dependant on what you want out of the car. Fuel mileage? Lopey idle? Friendly driver? If past posts are any indication, I think your compression is on the low side (those are AL heads on there) and so a big cam is killing your power. If you want the most power out of the current arrangement, probably the hot cam (or similar like the Accel/Ling 219) is the best choice. The Crower may or may not make a bit more at the sacrifice of being friendly. With a stroker, it'll probably run nice. Get into the 230's like the Comp XFI280, its gonna lope a bit and probably not yield as much power as possible because of the compression... but seeing whats posted above I dont think I'll recommend a comp cam anytime soon unfortunately.

 

Thanks for the great replies. This is all def opening my eyes.

I have the cam that I have now mainly cuz trickflow said to get it if I want to make 500 HP at the crank. So thats what I did. Mind you I knew almost nothing about motors back them, but I am trying to slowly learn.

So it looks like something in the 230 range with 1.6 Roller rockers?

I think we all agree on that right? Or are some of the cams that you posted madmax call for less?

I know that the last "best" suggestion was for a 225 and 232.

Maybe I will just go with that.


-Oh, I don't know if this will change your mind, but the intake is being changed over to an air-gap instead of the vic. jr.
- I am running a MSD digital 6 Plus ignition box and pro-billet dizzy.
- a nitrous plate
- 750 holley dp
- long tube headers, with a 3" Y-pipe and a 4" cat-back
- T-56 and 4.11s in the moser rear.

I think thats it.

(Since I am a newbie on this subject please expect stupid questions.)

 

Well, the recommenadtion they gave you, was based on that spec; which pretty much defined everything from there on out. Let's revisit that for a second.

Think of it this way: 500 HP out of a 383, is a little over 1.3 HP per cu in.

It's pretty easy to get .5 HP per cu in. Duh. A little tougher to get to .75, or .8. or .9, or even 1 HP per cu in, but still not too tough. But the curve of "ease" if you will, vs HP/CI, kind of starts to reach a "knee" shape, where every .01 HP/CI starts to come ALOT harder, once you get to around 1.2 HP/CI, in a SBC. Each one of those marginal .01 HP/CI gets "harder" than the one before. By "easy" and "hard", I don't mean the difficulty of assembling it; I mean more like, the compromises you have to make. What you have to give up to get that next .01 HP/CI. Things like, reliability (lack of parts breakage); expense; fuel mileage; vacuum; idle quality; sensitivity to ambient conditions; RPM range the motor will run effectively within; precision required in everything; and so forth.

I would expect, given the rest of the specs for your motor, that with the cam I called for or the one F-bird did (they're pretty similar, so I'd expect comparable results), you'll get about 425-440 HP. That's in the 1.2 HP/CI range.... more or less right at the "knee" of that "easy" curve.

Now ask yourself: do you want a 500 HP car that fights you every step of the way and costs an arm and a leg to run, when or even IF it runs at all (review some history here); or, would you accept a 430 HP car that you shut the hood and hop in and hit the key and count on getting to work in every day? In other words, adjust your expectations slightly, to bring them into accord with the hard reality you've already experienced.

I think that's kind of where we're all going with our suggestions.

 

230 xfi cam on a 113lsa in a 386 will be fairly tame. I hear its tamer than the popular old CC306 but will make more power/tq across the curve. i know alot of guys run the 224/230 cam in their 355's and runs great for a street car. LT4 hotcam 218/228 is also a cam 350 users have and works good fro the street.

i would not run it in a 383 unless your looking for a very docile car. its just too small IMO. 230/236 is a good grind and will make good power too

 

Dennis, you have a hydraulic roller? Do you have any interest in using a solid roller? I don't mean GO BIG OR GO HOME, just that you can extend your useable RPM range with a solid cam. Maintenance is really a non-issue with those these days. Look at Trevor Jacek on the drag racing board and ask for his advice (street driven 400cid with a small solid roller, low 11's).

 

It is a hydrolic roller yeah. I know people have street driven solids but I kinda don't wanna have to deal with them. If you want to switch cams, you need lifters. I want this motor to be as modular as possible since it is my first motor ever in my first car ever.

With that said, I too have a friend that has a solid lifter motor that he runs on the street, makes about 400 HP and loves it. (69 Camaro). I just like the idea of swapability that the hydrolic rollers offer.

Also if i start to consider more types of cams then I am never going to narrow this down. I would like to get a definitive answer on what cam to get by tonight so I can order tonight b4 I go home from work at 4:30.

The LT1 hot cam with the 218 seems a bit low since people are saying it is tame. My car is ridiculous now and has a huge cam. I have put 3000 miles on it so I am very used to the craziness of it. I pull like no vacuum and get bad MPG. So when you guys say well you are going to loose drivability and so on... Are you talking about loosing it compared to what I have? No right? You mean from like a stock car...


Anything I can swap to is going to be better than what I have. This thing is just huge compared to what you guys are suggesting.

230/236 sounds big but not huge. Anyone think that is a bad idea? Or does the first one that sofakingdom posted in the begining still seem like that best bet?

 

ive always had real good luck with lunati

 

Thats where you enter the subjective arena, whats tolerable to you might be unbearable to someone else.

I have the XFI280 in a 350, its fine by me. I would consider it *slightly* tempermental, but anyone who thinks its too much is a wuss. Mileage is fine, power is there but the current configuration is not ideal. The XFI268 would have been better with whats in the car now, but I have other plans in mind so I went with the other cam and for the time being I'm accepting where its at.

That said, you have to look at the rest of your parts too. Putting in a big cam with small port heads and no compression is a recipie for disaster on all fronts. Why have an engine that is on the edge of tolerable and have no power or mileage on top of that? Pick the right cam for your combination if you want the most performance out of it. If all you want is sound, leave it alone and drive it like it is. Chances are the 230 might be slightly large but without knowing a little more about what you actually have (like what your compression ratio REALLY is), its just guessing.

 

compression around 10 to 1 or so would be fine with that 280xfi cam.

 

Not really. The DCR is fairly low at that point, so much that with AL heads running 87 octane is rarely an issue. More compression or a smaller cam would be easy HP.

 

Well knowing exactly just isn't really going to happen cuz I am not going to open up my motor. I can take a very good educated guess and say what the guy who built my motor said. It has about 10.4 static and 9.6 dynamic. That was a long time ago and I can't seem to get in contact with him anymore, but I haven't really been trying.

I could give a rats *** what my car sounds like. I just want it to be powerful and reliable with fair MPG. I don't care about a lopey idle, or any of that crap.

I have built my car for me and thats it, no one else. I did the things that I did cuz I thought it would make the car better in my eyes, not in someone elses looking at me.

With that said, I am very aware that I need a cam that fits my motor like you said, but thats precisely why I started this thread, cuz I don't know how to do that!!!!!

I need help finding out what cam would fit my application. I know all my parts and specs. I just don't know exactly what my comp ratio is. I have a really good idea.

I also hear that my dynamic is so low due to my big cam. Since I have so much overlap my comp ratio falls. With a new cam that has less overlap shouldn't my comp ratio go up?

Seems to make sense or am I just not getting it.
----------
Oh and I run 93 ALL the time.

Does that help with what cam I should get?

And what effects do having Al. heads have on cam selection?

 

Then stay away from the 280xfi. I'll bet a dollar the 225 crower posted above will make you and your engine a lot happier. I'm sure you have no intentions of changing pistons or heads so your static compression ratio is fixed along with the head flow rate so the cam is pretty much predetermined. 218-230 will work, but probably 224-225 is ideal. Smaller is almost always better. Keep that in mind. Bigger is for those guys with lots of money, perfectly tuned engines, and they're searching for another 10hp at 7000rpm. Probably not you. Even with that 225ish intake duration cam, it'll have plenty of powerband and as a wild guess will probably peak somewhere in the high 5000 range. I'm sure the 230+ will put it in the low 6 range, and it wont idle as nice or be as easy to tune properly. Carbed right? Rich at idle comes to mind.

Static compression is fixed, thats not going to change. What will change is your dynamic. No way you have 10.4 static and 9.6 dynamic with that cam. I'd throw those numbers right out the window. The main question on your engine is the depth of the pistons from the deck, I think the rest is pretty much determined. I'd assume that 10:1 is more like where you're at, so ideally a cam in the mid 220's would be about right with a 383 and the trick flows you have. Dynamic compression is kind of a guessing game, but I'd say it would be physically impossible to have 9.6 dynamic on 93 octane without knock. The numbers you got both make no sense. They're bogus. If you really want to choose on your own, find Pat Kelley's DCR calculator and run it. You can also play with desktop dyno if you want, it'll show you what little is to be gained with oversized cams. But keep in mind that static and dynamic compression are two entirely different things. Static is fixed and can be determined to as much accuracy as your measurement devices allow. Dynamic is a fudge factor based on cam timing added into the mix and can vary for any number of other reasons.

AL heads allow and require more compression, because they pull more heat from the chamber (basically faster rate) than cast iron does so you have a power loss from that. They dont run as hot, so preignition is less of a problem, and you can run more compression to make up the difference. This also relates to the allowable dynamic you can run without detonating, so now the cam enters the equation.

 

I'm just guessing (I still dont know exactly what you have, just a rough idea), but with an assumed 10.4 static, with that cam you have now you have 7.0 dynamic.
Straight swap to the 280XFI is 8.0 dynamic.
The crower above I'm coming up with 8.4 dynamic, reasonable on 93 octane.

These are all guesses mind you. Are those really 175cc intake port heads? 61cc chamber??? Yikes. Excuse me if I missed it, but what pistons do you have? I think you posted it before. Your bore sounds like its 4.040. What head gasket? 5.7 rods?

 

I am not sure what head gasket I have. Nothing fancy. The heads I have are these.

http://www.trickflow.com/product/che...3degree175.asp
TFS-30300003

I assume the data on the site is fairly correct. Pistons are also nothing fancy, just some flat top pistons. I don't know how far my pistons are to my deck, but I do have that info at home I think.

I fully understand what compression ratio is and the difference between dynamic and static. I know all about fudge factors. i am a mech. engineer. Random factors like that is one of the things I have to account for all that time.

madmax: Thanks for the help so far. I am still a little lost though with all the questions. You said at one time that 224/225 would be ideal. After re-thinking is that not the case anymore?

I am headed home and will try and log on tonight. Can you order crane cames straight from them? If so I might as well get my intake and other odds and ends that I need now until I can figure out what cam I need.


here is a pic of my pistons when they were going in.



This is my CD site. http://www.cardomain.com/ride/782913/18

 

stock LT1's are runnign 10.5 to 1 and running bigger cams on stock heads..they seem to run fine.

XFI's wider LSA increases the intake centerline which increases DCR. And its duration isnt all that much for a 383-388 motor. Plus it has FAST ramps which i do believe will help close the intake valve quicker and should act like a smaller cam which will also raise the DCR. If you need more DCR, just advance the cam 4 degrees on install.

I think its a good choice

EDIT... never mind...I thought you ahd the 195 cc heads. with 175's i'd go with a 224/230 cam..maybe even the custom XFI grind lobes.

that big cam you have now should have no less than 195 cc heads ported. AFR 210's would rock with a 11:1 compression or abit higher

 

He does have 195's, whats posted above is wrong. Its posted elsewhere and the cardomain pics show what looks like 195, not 175. I also saw a picture of a partly assembled shortblock, those pistons look deep in the hole. I'm thinking... 10.0:1CR. He needs a 218-226 intake duration.

I have the 280XFI in a 350 with exactly 10.0:1. It runs fine on 87 most days. The DCR is too low, 10.5:1 or 11:1 with that cam on a 350 and 91-93 octane is easy power with no downside, no sense running lower or you end up with what he has now, overcammed. His current DCR is in the 6's, thats why its only putting down 344 at the wheels. I'm getting near that with a stock runner TPI, much smaller cam, partly obstructed exhaust, less cubes, less octane, and less headache and getting 21mpg highway to boot in a heavier car. There's only one real reason for that, mismatched parts. He NEEDS a smaller cam.

Alright. Its possible he's above 10:1, but not much. The problem with LT1's running more cam and being 'fine' is I've seen plenty of those go from a CC305 to 306 and gain virually nil, thats why going with the biggest cam you can fit doesnt work. There's nothing to be gained if the rest doesnt fit the bill.

 

well i'm just saying that a 383 is 33 inches bigger than a 350...so you can add 5-8 degrees to the cam. a 224 cam in a 350 will peak about the same as a 230 cam in a 383 with similar heads/mods. 383 needs more air so also abit more cam but not much. Either way, 220-230 degrees duration should make same if not more power, and especially across the rpm range than the current setup. 350whp is NOT hard to achieve with a 383 with that intake. Hell my buddies truck made an estimated 300whp with stock vortec castings, stock LT1 camaro cam, and rpm intake with 750 carb. 4000+ lbs and running 13.5's at 99 mph in the 1/4

 

Holy crap, OK a lot to digest here but I still don't really have anything I can call up CRANE to talk about.

I KNOW I am over cammed. I know I need a smaller one. I don't know enough about LSA to make any good decision on that. Also I don't know much about advancing the cam timing. I DO know that my SCR is far higher than my DCR and I want to close that gap.

Can you guys help me maybe come up with some ranges that I should look into when I call CRANE?

Intake duration: 218-226?
Exhaust duration: 228-236?
RPM range: 2000-5500
Idle: I don't care about the quality of the idle. It is ROUGH now and I am used to it, so it can't possibly get worse.

What other specs and ranges do I need to know? I want to get this cam in ASAP. Also want then new intake on there as well before it snows here and the car has to go bye bye for 3 months.

I drive this thing to work everyday so I would love to get the cam in there soon so that I can have the benefit of better MPG and so on.

EDIT: I do have the 195 heads. Sorry if there was a mistake. I am going to call CRANE today and see what they say. i will post whatever advice I can pickup. It would KICK *** if I could get a cam decision by the end of the day.

 

This is a new cam from CRANE.

How about this one? Seems a little small, but its nice that it is supposed to "com on" at only 1800 RPM. Looking at the #s, seems a bit small though.

http://www.cranecams.com/index.php?s...21&lvl=2&prt=5

 

Or maybe this is better since it is recommended for mild racing and might be a little stronger cuz of it. It says it has a fair idle. I fear that a "good idle" = too tame a motor.

This cam will take off 22* and 24* of what I have now. Intake and exhaust respectfully.

Power is good from 2200-6400, Not bad.

http://www.cranecams.com/index.php?s...31&lvl=2&prt=5

 

combination motorsports is big with the LT1 crowd... i like those grinds. 227/233 would be nice in that car.

 

That's a flat tappet.

If you want Crane specifically, look at this one.

http://www.cranecams.com/index.php?s...31&lvl=2&prt=5

 

sofakingdom: Isn't that cam for an 87-up motor?

Here is a suggestion that I got from a club member. I kind of like it since it is a nitrous cam and I just read an article that dynoed a normal cam and a nitrous cam with the same basic specs. Then they shot both with juice and the N20 cam made a ton more top end power with the same shot and lost less than 1 or 2 HP anywhere else. Seems like a good trade off.

Here it is. I know it is a comp cam, but bear with me

-------------------------------------------------

Cam Style:Hydraulic roller tappet
Basic Operating RPM Range:2,000-6,000
Intake Duration at 050 inch Lift:224
Exhaust Duration at 050 inch Lift:236
Duration at 050 inch Lift:224 int./236 exh.
Advertised Intake Duration:276
Advertised Exhaust Duration:288
Advertised Duration:276 int./288 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.502 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.520 in.
Valve Lift with Factory Rocker Arm Ratio:0.502 int./0.520 exh. lift
Lobe Separation (degrees):113
Intake Valve Lash:0.000 in.
Exhaust Valve Lash:0.000 in.
Computer Controlled Compatible:No
Grind Number:CS NR276HR-113

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It was suggested to use 1.6 rockers to get a bit more lift though. Would that be OK? I don't want to hit my pistons.

From the cam spec sheet above, don't i have like 558 lift? So I should be Ok right? How does the 1.6 over the 1.5s that I have now effect the max lift specs?

Thanks for any help. Everyday i get closer and closer to knowing what they heck is going on with cams, haha.

 

that sounds like a good grind. duration is fine and lift isnt bad. definately go 1.6 rockers as i believe trick flows flow best at .550 lift or so

that 113 lsa will make idle friendly and give good vacuum for brakes

 

yes it is. If you're using a older block pre 87 non roller block and retrofit lifters use the camshaft part number I suggested. its the same grind on the retrofit core. Also nitrous friendly.

 

Since your car is a daily driver and you are looking for more low end torque and not too much maint. or parts breakage I'd go with one of the smaller cams suggested. I had a Bullit custom ground hyd/roller cam that was 225/230@.05, .525/.525 lift 110LSA that was very drivable in my 383 orginally. With 10:1 compression and unported dart Pro 1's it ran a best of 12.02@113mph. It made tons of torque and was very tame to drive on the street, very fun combination. I put lots of street and strip time on that combo with no problems. I'd stay with something in the 225/230 or maybe 230/236 range with your goals in mind. Once you aren't driving this car daily and don't mind the extra hassles of a more radical combination step up to some larger better flowing heads and a solid roller and make some serious power.

 

MadMax wrote. "but I have other plans in mind so I went with the other cam and for the time being I'm accepting where". I love it hehehehe. Inside joke guys.

 

Well I have been getting a lot of good info in this thread. I appreciate all the help you guys are giving me. This cam has gotten the OK from a few of you if I use 1.6 RRs...

Should I keep looking and try and find a cam that will let me keep my 1.5s? Or is the better in some way to just go with a set of 1.6s?

Cam Style:Hydraulic roller tappet
Basic Operating RPM Range:2,000-6,000
Intake Duration at 050 inch Lift:224
Exhaust Duration at 050 inch Lift:236
Duration at 050 inch Lift:224 int./236 exh.
Advertised Intake Duration:276
Advertised Exhaust Duration:288
Advertised Duration:276 int./288 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.502 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.520 in.
Valve Lift with Factory Rocker Arm Ratio:0.502 int./0.520 exh. lift
Lobe Separation (degrees):113
Intake Valve Lash:0.000 in.
Exhaust Valve Lash:0.000 in.
Computer Controlled Compatible:No
Grind Number:CS NR276HR-113


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Only reason I want to really start to buckle down on a certain cam is that there are sooo many suggestions out there and I can see myself playing around with little options all month long. I will call crane today and see what they say I should have and post back here. I was hoping to do it yesterday but my sister needed her oil changed.

 

BINGO! As I began to read this thread, the GM 846 cam immediately came to mind. It's made by Crane, which is linked by sofaking above.
If you know a GM parts guy, you can get it cheaper than directly from Crane.
GMPP number 12370846.
These are making 400 rwhp thru auto trans LT1 setups with good ported stock castings.

Edit: For one step up in the GMPP line, check out the GM847 cam:
http://www.cranecams.com/?show=brows...tType=camshaft
But personally, I think it's too big. If you're tempted with it, definitely stick with 1.5 rockers.

You'll be happy with either 1.5 or 1.6 rockers with the GM846.

 

Looking at the specs of the 846 cam, I really like it. Looks like it might fit the bill nicely. Are you guys 100% sure about ordering it from GM and getting the same part that Crane sells?

If you are I will order it all up today. Maybe I can find this on summit since I am getting another bunch of stuff from them, like the intake that this cam will get.

I have an edel vic jr right now. I am thinking of going with and RPM air gap, these are dual plane.

This it would help or hurt to do that swap?

I know dual planes are better for street so thats why i figured I would swap now and help make more low end TQ.

 

Yes it is absolutely the same part. Crane makes it for GM.

The "846", and the Crane part # that's the same thing that I posted, are for 87-up (factory roller) motors. Sorry if I lost track of which kind of block you had. If your motor is not that, then you can't use it.

The cam F-bird suggested is very similar, but not quite exactly the same. I can't put any kind of "numbers" on how different it would behave for you though. Probably not a whole lot different.

You could however, call Crane and have them grind you that 846 cam on an "original" style roller blank, if that looks good to you. Or, use the Crower I suggested, which is also very close to it, but slightly larger; or F-Bird's Crane part #, which looks slightly smaller. They may not all be identical, but they're not far apart; all of those cams are within a couple of degrees and a few thousandths of each other, in most all of the critical places, and should run similarly.

Yes the RPM series would be a FAR better match to the new "toned-down" combo, than the Vic Jr. You should easily be able to sell the Vic and recoup a fair amount of the cost.

 

Yes. I just got one from GM a couple of months ago to put in a 383 LT1 for roadracing duty in a C4.

Since it's easy to swap intake manifolds later, I spare the added expense right now and stick with the Victor Jr to see how it works.