What should I do, my engine builder disappeared. I bought a 383 from a guy on this board a few years back. It is in my car now and has a little over 3000 miles on it. It has forged internals, trick flow 72cc 195 Al. heads., vic jr intake and a 750 holley DP. I also have sprayed it with a 100 shot soon to be 200 shot of juice. The car is a DD for 3 seasons.

Problem is that I want to up the power of the motor since it just isn't making what I want. It only puts out 344 HP and 340 TQ. Granted it has over 300 TQ by 3 grand and stays that way just past 6 I think, it just isn't enough.

I started a thread about wanting to swap cams and intake to bring the power band down into the RPM range that I can use.

Thing is, people keep asking me quetions that I don't know the answer to since I didn't build the motor.

I would have just called my builder, but he seemed to have vanished. Now I don't know what to do. I don't want to spend much more than $600 or $700 making this motor into what I really want.

To bring drivability up I got a new RPM air-gap intake. That should really help over the single plane of the Vic. jr. To match the intake I want to get a smaller cam. I have a 246, 254 duration cam now and am thinking of going with something like 230, 236 duration.

- Is this all I can really do to make the motor make more power where I want it with not ripping into it yet?

- I have no idea if it was 0 decked or anything like that. And I only "think" the motor is 10.0 compression. I would get a thinner gasket, but I don't want to pay for that kinda work now.



In the end I know I will need to take the motor out and have it looked though by a local shop and have them go over/ check and build, the motor so that I know the exact specs and my 450 RWHP can be shot for.

But for now, should I just get a cam in that range, slap on the intake and call it a day for a while, till i get out of school and can start planning what shop can go though the motor?


Thanks for any insight.

 

The changes you talk about should help driveability, but the bottom line is that your power is going to go down. It will be in a more useful rpm range, but it will be less power. You talk about 450 rwhp, and that is not going to happen (at least N/A) while keeping the driveablility you talk about.

 

I know that. I know all of that. I am expecting the #s to go down. I just don't know why.

The kit that was put togeather for this motor says that it should push 500 fly, and I am am only making like 380. Somthing is wrong

 

I think you're outsmarting yourself on this.

Go buy a cam, any GOOD cam from any of the top line of cam mfrs like we've been telling you, in the range we've been pointing you toward (mid-high 220s on the intake, high 220s - low 230s on the exhaust, tight LSA, .525" - .540" lift); and put it in. It's really not that tough. You can handle it. Just do it.

You will not make 450 RWHP with that. You aren't making it with what you've got, and never will (clearly). You will not make 450 RWHP with the rest of the parts you've got no matter what cam you use, unless the short block is built PERFECTLY, everthing about the heads and induction is tweeeked JUST RIGHT, and every detail is maximized to PERFECTION. Whether that was done to your motor or not, I have no way of knowing for certain, but it would seem not based on the results we've seen thus far. At this point, you need to just take what you've got, do the best you can with it, and let the numbers fall wherever they fall. Then as you say, later on down the road, whenever you're ready to do whatever it is that you want to do that you think will take 450 RWHP, and you don't have to worry about it being a daily driver any more, take the quest back up again.

If the motor wasn't built properly for the 450 RWHP goal, for instance if its compression is lower than you've been led to believe like it appears to be, you need to just work WITH whatever is there, and not stress so much over what's NOT there. Swapping a cam won't fix that. No cam in the world can make that right. It would be complete tear-down and start-over time in order to REALLY get it RIGHT. At this point, if you're not willing to do that, it's best to make whatever is actually there however good it can be, and move on; and not continue to shoot for a goal that's obviously out of reach at this time.

Just get a cam - I'd STRONGLY suggest that it be LESS THAN 230° - change it out, and see where that leads. Who knows, you might find that it makes the same power it does now, just in a RPM range you can actually use it; and meanwhile, it'll be a whole lot more fun to drive, and cost you less in parts and gas to operate it. Not to mention aggravation.

 

I hear ya. I will order up a crane that looks to fit the bill and toss it in with some help. Can you get a cam out with the motor in the car? If I take out the fans and rad?

Also is it true that i need new lifters? What about springs? If the pressure they want is not higher than what I have, can't I just leave it?

 

Re-use your existing lifters and springs. They should be fine.

Yes you can do a cam swap with the motor in the car. IMO it's easier and all-around better to pull it. With it out, you can see what you're doing better, clean stuff up better, and get things to seal back up better; and you don't have to spend as much time laying on wet filthy oily ground up under a motor dripping fluids and funk in your face, and you don't end up spending a day and a half leaning over a 3-foot-tall thing (fenders) working on something a foot and a half off the ground 3 to 4 feet away from you. But it can be done either way. To do it in the car you'll need to remove the radiator, the AC condenser (which you can remove the compressor from the motor and th econdenser from the car, and rotate them up out of the way together WITHOUT disconnecting the lines), and the vertical bracket that's under the hood latch.

 

Yeah, The way things are for me, i am going to try and do it in the car. If you have ever seen my engine bay, I don't have anything in there at all almost. I even have a manual steering box. Only accecory I have to take off is my alt and water pump of course. Shouldn't be too bad. If I have someone help me a little, might be able to get it done in a weekend if everything goes well.

I guess I will wait till the real cold hits and the car is off the road.

 

If u r gonna put a smaller cam in it. You should get the COMP 230/236 .510/.520 cam. I think you would really like this cam and you would not lose too much. It would fit your application PERFECTLY!

 

I was looking at that, but seems to be that people say it is a little too big. It is in consideration. I just really want to bring the revs down and make good TQ.

 

Putting a cam in a 383 without know what rod clearances you have is risky business.
Just a word to the wise.

 

Do you have any idea what you cranking pressure is?

 

I've never heard anyone suggest using old lifters on a new cam. Will that work? And, for how long?
This is not a flame, just a question. I have not tried it myself but, from what I've been told, the cam and/or lifters will wear prematurely if they are not 'matched' so to speak. Heck, when I know I'm going to re-use a cam, I even make sure to mark the lifters so I know what lobe they were on.

Like I said, I've never used old lifters on a new cam so, I'm interested.

 

if its a flat tappet cam the lifters must be replaced, but IIRC, he has a roller cam in it, so as long as the old lifters are in good condition it will be fine.

 

Thanks for the reply. I didn't think of rollers!

 

Yeah, they are Hyd. rollers. The car has a HUGE cam now, so I am going with a smaller one. Thats why I wouldn't expect there to be too many problems with it.

The only reason I would ever re-use these lifters is cuz they are roller and cuz they only have 3000 miles on them.

I bet when I get them out they will look practically new.

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2oldFbody: I tried a compression test on cylinder 3 yesterday right before it got too dark to work on the car and kids started coming around looking for candy. It held about 170 PSI. The gauge was SUPER screwed up (borrowed), but I made sure it was zeroed and read the same PSI as a compressor I have. So it must be close to that.

I am tossing on a better gauge today and trying again. The car wasn't hot though. But still, 170 shows that it is holding pressure well. I want to do a full warm test this weekend. I hear that kind of info helps figure out a few things.

 

I am running the Comp xe282hr cam with the RPM Air-Gap on a stock bore 350. The rest of the combo is in my sig. I dosent seem to big for the 350 and the cam/intake combo really pulls all the way thru the rpm range.

Also you might consider getting it a small base circle grind for the clearance.

 

Nice setup. I will look up the specs of that cam. You seem to be making good #s with that cam. Wonder what a little more displacement in my stroker would do to it.

I have a sorta similar car as you bluegrassz. I have a 6 speed and 4.11s and a 383. Maybe that cam will work. I will call my dyno shop and see what they say.

Thanks for the suggestion

 

My cam is set up with 1.5 roller rockers. Which are you using 1.5 or 1.6?
With 1.6 rr, my cam specs would change to like .544 and .554.

With the 383, you could go to the xe286hr instead of the xe282hr. Just a little more lift. It should be a strong runner. My cam/intake/heads really seem to flow well together. My car pull strong all the way through the 1/4. It has good bottom end as well as top end.

I really like the RPM Air-Gap. If I ever build another street car, it will definatly have one.

Oh yeah, your welcome!!

 

Cool. I will look into that as well since I run 1.5 and would like to stick with as much stuff that I have now as possible.

Good to hear that you like that intake so much. I should be getting a permastar coated one on Sat! Can't wait to see it.

 

What does your car do at the track? Just curious.

 

no idea. has just over 3000 miles from driving to shows and tunning. Thats all. It has just one summer on it all so far.

 

The XR282HR is the same one Z28freak posted up there.

I had one of those too, in a 400, with 1.6 rockers to get some lift. Ran great, for me. But my own personal tolerance for, and LONG experience with, "big cam" behavior kinda distorts that. Obviously I don't have too much trouble tuning around "not enough motor" for a cam, more so than most it would seem.

After all, there's no such thing as "too much cam"; only "not enough motor". Right? Compression above all else.... sound familiar?

IMO it's bigger than what you need; on the ragged edge of "too much", given your whole history and all that. You've already got burned once by going for broke. It makes more sense now to err toward the conservative side, and get some tuning experience under your belt, before trying to REALLY bite off. I'd suggest staying with something that has a little less duration and a little more lift.

 

My "Dino" cam seems to do really well in my motor. But I am also looking for options on a solid roller. (see thread below)

 

Yeah, I saw that and it was the reason I posted. I wanted to give first had account of someone using the cam. My cam is cut on a 112 LSA which does help tame it a bit. Althougth it is on the edge for my stock bore/stroke 350. I am however running 10.3 to 1 compression.

I had in my mind that this cam would seem more docile <-spelling in a 383.
The next step down the xe276hr would be a good choice also. Anything less and I dont think he will be happy.

This is just my opinion and my experience with the xe282hr cam.

 

Searching through summit best i can, what about this:

http://store.summitracing.com/partde...8&autoview=sku

And a set of 1.6s. Or is there a better cam that will not require the 1.6s? i can't find it on summit....

 

OK well I dunno what the F... deal is but I can't find any of these cams. I searched comp, and all over summit and I just can't find anything!!!!!!!!!!!!!!!!!!!!!!!!!!!

Ugh...


I find similar things but never what you guys are talking about. PLEASE LINK ME OR TELL ME HOW TO FIND THEM!



I toss the xe286hr # in the search at summit. nothing. And comp, nothing. Those are comp cams right???

God damn it, I am getting so frustrated with this crap. I am a very patient person but I have never had to hunt down a part for 3 weeks just to still feel like I am at square one still!!!

 

There is no XE286HR. The closest thing they have is the XR282HR and the XR288HR.

But those are sort of like "model names"; they're not how the cams are listed in the catalog.

For help with Comp, go here; click on Small Block Chevy cams; and scroll down a ways, to page 13 of that file. You'll find those model numbers, XR276HR for example; and next to that, grind numbers, like 12-423-8 for example. THAT'S the number you look it up by; like http://store.summitracing.com/egnsea...+115&x=36&y=11

Why the nitrous grind? All that will do, until you get up to 200HP or more of nitrous, is cost you low-end torque. It's not the way to go.

The cam I linked to right there, would be the closest one in Comp's line to what you need, except that it would benefit from 1.6 rockers, with the heads you have. If you use the Crower one I put up there a long time ago, you come up with about the same specs as that, except using your existing rockers.

 

Can you link the crower from summit? I can't find it. Please.

 

http://store.summitracing.com/egnsea...DS=1&N=700+115

They really don't show the specs there; but you can go to www.crower.com and then to the Master Catalog, then to page 33 of the file (p 34 of the catalog itself); and there you will find it.

Summit uses a 3-letter line code and the mfr's part #; so Comp for example is CCA in their system, Crower is CRO. Remember that the Crower # was 00468; so you search on CRO00468. Or for the Comp grind above, it's CCA124238 (you can put in or leave out the dashes, it doesn't matter). Lunati's code is LUN; so the Voodoo cam close to this you would search at Scummit as LUN60211.

Jeg's does the same kind of thing except they use a random 3-digit number as the line code. So to look up a number there, first go look up some other part by the same mfr, by description; get the line code; and search on that plus the mfr's part #. If you do that, you will discover that Comp's line code there is 249; so to find the XR276HR, you'd search for 249-12-423-8, like this http://www.jegs.com/webapp/wcs/store...m=249-12-423-8

All of these mfrs put their catalogs on line, although some are better than others. Crane's is pitiful, and Lunati's is full of mistakes and VERY skimpy, and Isky's is incomplete as well and hard to use. Comp's and Crower's are pretty good. Bullet puts their whole lobe catalog right there along with the characteristics (high/low RPM, symmetrical/asymmetrical, etc.) and you can just pick out a couple that make sense for what you're doing. IIRC the lobe numbers that I gave you in their line, are high RPM (easy on parts), asymmetrical (set the valve down gently for less noise and wear on the valve and seat), and high lift.

 

Wow, I like that crower 00468. All the specs that I seem to want. Not bad at all. Now that 110 LSA... Isn't that a little small? Am I still going to be able to pull good vacuum with an LSA that small? Fill me in...

sofakingdom: You are my best consutant here. You give this the green light for a nice $315? Lemme know.

If there is any reason you feel like it would be bad I will not get it. I will also pass the part by my dyno shop and call crower. If the dyno, you and the crower all think it will fit my motor just fine, then I will order one up.

This will be a great day if I can finally get my cam ordered!!!!

 

That cam should make my heads flow around 176 on the exhaust and they are already maxed out on the intake at somce # that I can't remember now.

But i really like the lift of the cam.

 

dennisbernal91z,

A link you may wish to look at. Just trying to help ya out

http://www.compcams.com/Technical/Cu...ML/128-169.asp
http://www.crower.com/misc/m_cat.shtml

 

LSA's effect on vacuum works hand in hand with duration.... specifically, the larger the duration, the larger the LSA needs to be in order to maintain idle quality.

At mid-220s of duration, 110° LSA is actually kind of conservative. It shouldn't present any kind of tuning difficulties at all.

The tighter the LSA, the "peakier" the torque curve is. Widening it tends to decrease low-end and midrange torque, and spread the curve out some toward the high side. Pretty much the opposite of what you'd want for a street motor. The reason it's done in FI setups, is for the idle situation: it's MUCH harder to tune a narrower LSA cam under FI, because the computer basically doesn't have the right sensors to tell what the engine is really doing, under those circumstances. It has to look at what limited info it can see (vacuum and TPS) and try to infer how much fuel is needed. But a carb, which reacts DIRECTLY to flow and vacuum, can handle it just fine.

Given that your whole valve train is already set up for about that same lift, it should be just a drop-in.

Might be worth a call to Crower, and see what the charge would be to have it ground on a small base circle, if any (part # would be 00468S); like Dyno Don said, better safe than sorry. Looks like it has to be ground ANYWAY, so you might as well head off any problems you can, on the front end. You know, a fence at the top of the cliff rather than an ambulance or hearse (and a lawyer) at the bottom.

 

Do I just say I want a smaller base circle? I don't know anything about that. How big is normal. How small is too small and why do I want it to be small? Clearance due to the 383? Do I just ask for the 00468S and thats all?

I really need this spoon fed to me. I haven't like this much of a newbie in a long time. haha.

 

You do NOT need a small base circle cam. Do NOT listen to anyone who says that you do. You a standard base circle now with .558 lift and are stepping down. So tell me why in the hell you would need a small base circle cam.....
Measure a pushrod, this can give you an idea of if the base circle on your current cam is smaller than stock. I'm sure your builder clearance the rod bolt shoulders plenty if he had any idea whatsoever of what he was doing.

 

"Stepping down" makes the cam lobes LARGER.

Think about it.... cam lobes are made as absolutely tall on the nose as they can possibly be, and still fit through the cam bearings, so that the cam can be installed. That's basic mechanical engineering, for wear, strength, etc.: make the part as large as it can be.

Lift is the difference between the height of the nose and the height of the heel.

Therefore, the "bigger" the cam, the "smaller" the heel; because the nose is ALWAYS the same height. That's also why you can take a worn cam, and re-grind it "bigger": you just grind more off of the heel than the nose.

Also, the cam's timing has as much to do with whether rods will hit it, as it does with lift. That can be difficult to predict.

You can't tell anything at all about the cam by measuring a push rod, especially with aftermarket heads; and ESPECIALLY ESPECIALLY with TF heads. They are notorious for needing attention to that detail. Who knows if whatever "deviation" from "normal" that one might find, is due to cam base circle, valve length, valve location in the head, etc. etc. etc.

SBC cams are ground on a 1" base circle, usually. The lobes are of course much larger than that.

A "standard" small base circle cam is ground on a .900" base circle. That gives .050" more clearance. Might not sound like alot, but it can be HUGE sometimes.

However, in the case of the Crower cam, it's not really very much smaller (larger diameter heel part of the lobes) at all, because the lift is pretty close to .550 on the exhaust side IIRC.

As a builder myself, I NEVER EVER touched rod bolts for clearance, except as a VERY LAST resort. However in Dennis' case, the rods might not even have bolts at all; they might be cap screws. I don't know that.

 

alright then, according to you its fine then. From the highest point of the lobe is the same, which is where it would contact the rod. So therefore, it'll be okay.
Whatever.....

 

No, the highest point is NOT where it will contact the rod.

The point where it will contact the rod is when the rod bolt is up in the cam tunnel (around 45° from TDC on whichever side of TDC, depending on whether it's a left-bank or a right-bank rod).

If you examine a cam's profile in relation to crank position, you will quickly and easily see that the tip of a lobe is NOWHERE NEAR pointed right straight at the rod at that point. Some other part of the lobe is there waiting for the rod to come up and hit it.

Keep in mind also, that advancing or retarding the cam will change the intake lobe's tendency to interfere with the rods; and both that, AND the LSA ground into the cam, will determine the exhaust lobe's issues.

So, what "will be OK"? What's "fine then"? What are you talking about?

 

Here is the bottom end of my motor



Looks liek I have bolts and not cap screws. Is that bad? You made it seem kinda like it is from what you said earlier.

And here is my motor with no heads. Don't know if this helps at all but I know sofakingdom you wanted to know how deep into the boerd my pistons were. I know you can't tell if those pistons are at TDC and they probably are not, but thats the only pic I have. But thats another thread and another issue.




So the crower 00468? or the S model? This is just a street car so maybe it is easier to play it safe with the S part right?


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Just wanted to say that my intake is at myt house. i just checked my fedex shipping info online and it says dilivered. One day early too!!!

Not bad. Now if I could just get a tinny bit more advice on a cam I will be outta the woods. Not that it really matters since I am not going to toss it in till after the car is off the road for the year anyways, but still, it would be nice to have all the parts figured out.

 

Those ARE CAP SCREWS. Those are H-beam connecting rods. bolts go in from "top" of the bottom part of the rod and have a nut on the bottom. Those just thread in from the bottom and give a LOT more clearance....this is good....you will not need a small base circle.

 

I think you try swapping the an RPM AirGap intake without swapping the cam. I think this might give you some of the low-end that you are after without sacrificing the screaming topend.

 

Nice. So I should just go ahead and order the 00468 Crower cam?
----------
hmmmmmmmmm. Never really considered that. Maybe you are right.

Intakes are simple to swap from what I hear. I have never done it but on a carbed motor like this with no accecories and stuff. i think I can do it in an afternoon no problem. Then tune the carb as best i can and see how it drives.


only problem is that my idle will still be choppy and bad. But who knows. might help a little.

 

No, get the Comp XE282hr.

 

Right; those are cap screws, not bolts & nuts.

They usually give a good bit more clearance than bolt & nut rods.

However, I notice QUITE A BIT of grinding on the block; not a good sign. Most builders don't grind on blocks any more than they have to. That much grinding would tend to indicate that whatever kind of rods they are, their shoulder, i.e. the place where the bolt head would go if they had bolts, may still be kind of tall. In fact, looking at the #3 rod, the only one that you can really see that part of it, it looks kind of tall to me.

On the other hand; here's how much DIFFERENCE there is between an Eagle rod (I think that's what you've got?) and a stock "X" rod. As you can see, the Eagle has nearly ¼" more clearance than this one (a 305/350 rod, though). Unfortunately I don't have a stock 400 rod laying around, outside of a motor, which would tell the tale FOR SURE; since stock 400 rods clear stock base circle cams, then if the Eagle rod was the same size as or smaller than the 400 rod, you'd be able to tell FOR SURE that you do or don't need a small base cam.

If you order the S version but don't need it, nothing bad happens.

If you don't order the S version but DO need it, you're hosed.

I'll leave it up to you to make the choice.

 

I see your point. I am def a safe rather than sorry kinda person. But i don't think I am going to get the crower. My dyno guy really likes the XE282HR

 

Yeah I have one too, I like it.

But just because I like it, or whoever does, doesn't make it right for you. I think it's more than you really need.

However, I think it'll at least make your car a whole lot more useful, and less of a hassle.

 

agreed intake swaps are easy to do. you can do that yourself.

cam is abit more difficult from what i see and i hope to be doing mine this year but that 282HR isnt bad. definately much better than what you have. still like the 230/236 grind tho

 

I am aware that the duration is still high, but the lift is much lower. It will make less noise since the motor doesn't need to to push those vavles as far. And the vacuum should realy improve. I got the new permastart air gap, man that is a nice looking intake.

I am going to have them do the cam, since I don't have a lot of the tools to do it and I don't really know all the steps in the cam degreeing process and stuff. It is also getting really cold and VERY dark now with the time change so I am going to have them do the cam change.

I think you can do it all in the car with the rad out, if they do it that way, dyno guy says it will only cost me 350 or so, 400 if they need to tilt the motor to get it out. Really not bad at all, new cam and intake all done in 2 days or less for 400 max, I like it. I am going to see if I can toss them another 200 or so and get a dyno tune and pull with the 200 shot.

I would also like to try My 1/2" spacer, no spacer and N20 plate combo to see what combination makes the most power.

 

Sounds like a good plan.

Let us know how it works out.