Camshaft dillema

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Miszny

Miszny

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Hello

At the beging want to say that my questions are "location" and lack of knowledge/experience driven so be patient please.

Here is the thing:
I have 471 motor in my Duster.
Few weeks ago it turned out that one lobe on my cam ate a hole thru one of the lifters, so cam and lifters are junk.
I ordered a new cam and lifters set, I had Comp Cams 21-225-4 cam in it and ordered the same thing.
My supplier made a mistake and sent me 21-224-4 cam set.
Here are links to specs of both cams:
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=709&sb=2
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=708&sb=2

Does it make sense to keep the wrong cam and put 1.6 rockers on it to have similar lift and also advancing it 4 degrees to make it work with my stall converter or should I send it back and wait another 2 to 3 weeks for the correct cam?
I have the 1.6 rockers set that I can bolt on and go, with replacing cams problem is that I need to wait 4 weeks... Welcome to Poland.

Any advice?

Cam I had .507 / .510 lift with 1.5 rockers.
The wrong cam I got would have .520 / .524 with 1.6 rockers.
I have the room for extra lift.

Duration of the wrong cam is big difference:
274 intake 286 exhaust vs 284 intake 296 exhaust on my previous cam.
Duration @ .050" Lift in old cam 240 in 246 ex
Duration @ .050" Lift in new cam 230 in 236 ex

if I add 4 degrees (i can advance 4 or retard 4 with my timing set) will it be a sensible compromise?
I have 3000 stall converter and as is the cam they sent seems to be a wrong idea.

Any advice?
 
The duration @50 is considerably less in the new cam. If you like the one that was in there I would get that one .Why does it take so long on the shipping?
 
If you lost a lobe there's a reason for it. How many miles are on the engine with the old cam? Do you have true dual valve springs or single with a dampener?
 
Holly sheep shat batman. Now I see why it takes so long. And I'll bet shipping is a lot! That might change my mind into using the one sent you.
 
Well, I tried to use what I got not to spend half of summer looking at the car... If it makes no sense than waiting it is. My hope was to advance it a bit and give it 1.6 rockers to at least cure part of the problem. Rockers I do have...
Engine was built in 2007 and rest of the cam is perfect so no idea what happened.
The springs are Comp, recommended for the cam I had by manufacturer.

Id rather wait and get what is better but was sure that giving it better lift with rockers and degreing it the right way would make what I have acceptable.
 
I'm a use what you have kinda guy,,What are the plans for the car's use ? If you are looking to have fun on the street I see no problem. If you are racing and need to extract every bit of power,,well that's a different story.Summer is short and I believe it gets pretty cold winters in Poland.Why wait.
As far as the cam that got wiped about that time (07-ish) Comp had some metallurgy problems.We had a 410 small block that destroyed itself on the first pass.Comp cams took the blame and paid to repair the engine thru Indy Cylinder Heads. They didn't have to,No warranty racing,, but they did.
 
lf u use the new cam do not advance it 4 degrees. the new cam has less duration = more low end power, less top end, advancing it will be even more low end and less top end. I would run the new cam straight up, maybe with the 1.5 rockers, not knowing the whole combo that u have, the less lift will last longer
 
Comp recommends 2200+ stall converter (1900-2900 in cam spec) vs 2800+ stall for old cam (2400-3400 in cam spec). So perhaps I should retard it to get closer to what I may use. I have 3000 stall, 727 manual vb and 4.11 rear.
 
You want to wait or you don't. You cannot dink with the XE274H and turn it into a XE284H. You either want to run a 10 degree smaller cam or you don't. In this case the lift isn't going to make as much difference as the duration.
 
Yea, duration is not something that I can change with anything but I was hoping to compensate for it...
I'm crazy by just having this car here. All costs me double and I wait forever for all parts. Fun fun fun... Ehh.
 
Miszny said:
Yea, duration is not something that I can change with anything but I was hoping to compensate for it...
I'm crazy by just having this car here. All costs me double and I wait forever for all parts. Fun fun fun... Ehh.
Click to expand...
Actually duration MUST CHANGE with rockers change, need to think how to calculate that.
 
Personally I would send back the cam and order a different cam all together. I have been having good luck with howards or Lunati cams or the HL series comp cams. Cams that take advantage of the .904 lifters.

Seat to seat duration stays the same, duration at anything above seat will be slightly bigger wont change as much as putting a bigger cam in. When I graphed out my cam for my 360, i picked up 2 deg duration at .050 going from 1.5 to1.6 and about 4 deg at .200 my is 226 dur at .050.
 
duration is said to increase slightly with an increase in rocker ratio, I don't see it. who has measured it, I do not want to hear theory
 
What i just posted is measured. It required me to use 2 dial indicators. Took measurment of lift with 1.5 rocker, used an adjustable pushrod to get max lift with 1.5 ratio rocker, took measurments at .050 lifter rise and .200. and marked degree wheel, also took measurments at the retainer for both ratios. The higher ratio had slightly different VO and VC #s (not actual openeing and closing of the valve but .050 and .200 #s) not much like I said. I graphed everything out on paper and turned both into lobe profile graph. It doesnt make the cam any bigger but it did change the events seen by the valve slightly. I really wish I had one of these.
 
Duration @ lift must change with different rocker ratio, but this is not huge numbers gain.
What I hoped for is to move the curves a bit up the rev band to be able to use what I got with my stall converter. So I was thinking about advancing or retarding the cam.
The 21-225-4 cam worked great for me.
 
Hell install the one you have. As mentioned you don't need more bottom so install it at the recommended c-line. If it doesn't work out to your liking, drive it while you order the cam you wanted in the first place.
 
The manufacturer has two spring types listed. One is a true dual spring with a dampener, one is a single spring with a dampener. I ask because the break in process for the new cam is different between the dual and single springs. Also because I wouldn't run the larger cam with the single springs.
There is no significant duration change by going with 1.6s. The ratio affects the rate of lift, because it's opening the valve further for the same given number of degrees of crankshaft rotation. Higher ratio also means the effective pressure of the springs is less because of the lost leverage. IMO - if the lifter went bad, you should check the pressures of the valve springs and if you want to go with 1.6s, replace the singles with the duals if you go bigger.

My advice based on the info given - go with the smaller one. Put it in at the recommended ICL. Run the 1.5 rockers. If you have dual springs - pull the inners for the cam break in process.

Advice based on your "wants" - run the bigger, replace the springs with duals (may mean machining the heads depending on what you have), and run the 1.6s. Pull the inners for the cam break in.
 
OK some history of what and why:
Last year before I put the car in storage for winter it started running a bit wierd and lost power. I wanted to inspect this before I took the Duster on the road this spring.
I took the covers off and realized that something is wrong with last lifter, I could push the spring deep in it with pushrod.
I took the intake off and saw that the cam is too much toward back of the engine and lifter is almost eaten thru, with hole on the bottom of it.
I took the timing cover off and found that cam sprocket is loose on the cam, the bolt that was in there I took out with my fingers, dowel pin in the cam was all smacked, the hole for the dowel pin was oval and timing chain was just on one row of teeth on the sprocket!
Not a nice view... I had to take the oil pan off to get the metal shavings from there, also had a chance to clean it.
So next I took the heads off to see how are things there. All exhaust valves were garbage so I gave both heads away to be reworked with new exhaust valves with 3 angle valve job like I had before. I have Wiseco forged flat top pistons, all pistons have small hit marks from the valves hitting but they seem intact.

So now the heads are waiting to be installed, gaskets and all the stuff is there to put it back together. I ordered new cam(identical as I had) lifters, some brake-in lube etc... I waited for the parts to put it back together this weekend and all was good till I opened the box with parts. My jaw dropped when I saw the cam... So I tried to save the day and bothered you guys with all my questions.
This engine was great before this happened and I was more than happy, car was very quick, sounded great etc.

As for brake in procedure I was thinking to use stock stamped rockers set, as final set I want to keep the adjustable 1.5 rockers that I had on it before.

I checked the springs and they are single with dampener, but the place that did the heads measured the springs pressure and it seems mine are harder than what Comp advertized on the website: installed height is 1.880 seat load is 130#@1.880 and open load is 350#@1.360, coil bind 1.175...
I have 452 heads that are ported to flow 280.11 @ .500 lift.

I did not put this motor together but it worked very very well as a package and made my Duster all day low 11s car, with shot of nitrous would be in 10s... I was thinking to put procharger in but well my plans changed to make it run instead.
As I am cam stupid I looked for advice... Already ordered the cam I had before, hoping this time I will get what I asked for.
My car is very exotic here, there are like 5 Dusters in my country and only two are big block.. Getting anything for these means you need to be patient and be prepared to pay almost 300$ for a flat tappet cam with shipping. All the prices you can practically double which sucks.
 
Ok. Sounds like you took the right steps then. I still think you're better with the smaller cam, and "too much" spring pressure is better than not enough. Rocker choice means nothing for the break in really. You do know that 1.6 rockers use ball/cup pushrods, and stamped steel 1.5s use ball/ball... Right?
 
Yes I have both pushrods style, but thanks :)

Can you explain why smaller cam is better for me?
Better how? I was worried that Comp says the wrong cam I got should be used with 1900-2900 converter (RPM range 1800-6000) where the cam I had before was 2400-3400 stall (RPM range 2400-6500).
Also the engine revs very quick so I was thinking that the previous cam had better characteristic for that.
Where am I wrong here?
 
I would advise checking your valve to piston clearance when you put it together since you mentioned the valves hitting the pistons.
 
Miszny said:
Yes I have both pushrods style, but thanks :)

Can you explain why smaller cam is better for me?
Better how? I was worried that Comp says the wrong cam I got should be used with 1900-2900 converter (RPM range 1800-6000) where the cam I had before was 2400-3400 stall (RPM range 2400-6500).
Also the engine revs very quick so I was thinking that the previous cam had better characteristic for that.
Where am I wrong here?
Click to expand...

No right or wrong, just opinions. I read what you wrote and I think the smaller one would be better. What I based that on.... You have a 471 - longer than factory stroke, but it's only about 4% more than a factory stroke. You have iron heads with big chambers so compression can be hard to come by and there is no quench effect. You have a fairly low stall street type convertor. You had marks on pistons from valves hitting (this might have been from the timing set issues, but it could also be from not enough valve spring). You have single valve springs. It seems to me that a smaller cam will give you more torque and cylinder pressure which IMO is what you need and the sprigns you have will have an easier time controlling the valves.
Anyone can disagree - just telling you my thoughts but I'm a few thousand miles away and never dfrove the car....lol.
 
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