Head and cam swap Goodwrench 350

the balancer is at about 12ish and the timing pointer is at about 2ish so you think the cover and balancer miss matches
 
well a timing covers. or new timing tabs are usually much cheaper than a new balancer

http://www.summitracing.com/parts/MRG-4600/?rtype=10

mrg-4600_w.jpg


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viewtopic.php?f=70&t=1015
 
ZZ71s said:
You hear people talk about balancers slipping any truth to this
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the stock TYPE balancer has a rubber ring glued between the inner hub and outer inertial ring and yes they do deteriorate over time and have been known to slip, especially if subjected to being oil soaked over time, or someone used a hammer vs the correct tool to get it back on the crank
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failed_harmonic_balancer.jpg


viewtopic.php?f=53&t=3554&p=9433#p9433
 
I am having a little trouble figuring the Compression ratio tthe cal on the summit sight gives me one number and this one gives me another http://www.csgnetwork.com/compcalc.html
I have 350 58cc chambers the pistons are down in the block .024
theres a 10ish dish head gasket .028
the summit cal gives me 10to 1 and the other one gives me 13 to 1
what am I doing wrong.
 
Looks like the Dynamic CR of 8.6:1 is too high with the Voodoo cam installed Dot-to-Dot or 4 degrees advanced. It would be significantly better if you installed it with Zero Degrees advanced, this would drop the DCR to 8.37:1. But....You would be giving up a few hundred RPM on the bottom end torque. It still looks marginal to me for pump gas on 91 octane.

Note: Your engine calcs are Engine 4 & 5 in the picture.

Now I don't have experience to back up what I've said, it comes from what I've read here. Grumpy will have a much better opinion on this.

Is the engine out of the car or are you doing this cam swap in the car ???
 

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I am worried about the 10 to 1 cr and the voodoo 60101 will the 93 octane keep me out of trouble or should I get a thicker gasket
 
ZZ71s said:
I am worried about the 10 to 1 cr and the voodoo 60101 will the 93 octane keep me out of trouble or should I get a thicker gasket
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A thicker head gasket may make it worse not better. The Deck Clearance would increase making it more likely to have detonation problems, but on the other hand you would lower the CR. So in the end it maybe just a wash.

Since you have the engine out of the car, what's the chances that you could have the block milled ??? It would require completed dis-assembling the engine, but you would have control over the deck clearance and could be reduced to 0.040" to 0.042".

Before you start making any decisions, please make sure the numbers being used for your calcs are correct. There are three numbers that have very little effect on the calc and can be ignored, they are "Gasket Diameter", "Top Ring Height" and "Ring Land to Cyl Bore Clearance". It would be very helpful if you could measure the combustion chamber volume, but this is getting more involved than you want most likely.

If you decide to get into a complete rebuild, I would be glad to do any calculations for you or you can download the calculator and play with the numbers yourself.
viewtopic.php?f=99&t=4458

Again, I CANNOT speak from experience only what I've read and learned in the last 9 months, but it looks risky at best. Hopefully GRUMPY with comment, he's been there done that a few hundred times and could speak from experience.

Look thru the thread for more info: viewtopic.php?f=52&t=727&hilit=dynamic+compression+ratio

 

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if your limited to pump gas its best to try to maintain a 170f-180f engine coolant temperature, and ideally oil temps only about 10 degrees hotter, and an 8:1 dynamic compression ratio, its not that your engines going to instantly self destruct if you were to build it using lets say a 8.5:1 dynamic compression ratio, or even a bit higher, its just that the higher it goes the more likely yo are to get into detonation,yes, there are things that can be done like getting the quench correct,oil coolers,octane booster, inter-coolers, large capacity baffled oil pans, running the fuel/air ratio a bit rich near 12.8:1 vs 14.7:1 retarding the ignition advance curve, using aluminum heads polishing the combustion chambers and in some cases using water injection to delay or prevent detonation. but avoiding a problem tends to be easier than reducing the symptoms, or preventing damage, if proper planing could be used to avoid them.

related info

viewtopic.php?f=55&t=2718

viewtopic.php?f=57&t=4701

viewtopic.php?f=55&t=109

viewtopic.php?f=70&t=2798

viewtopic.php?f=52&t=2630&p=13144&hilit=polishing+chamber#p13144

viewtopic.php?f=70&t=202

viewtopic.php?f=70&t=4683

viewtopic.php?f=55&t=613&p=12677&hilit=toluene#p12677

viewtopic.php?f=86&t=4484
 
Alright you guys got me good and confused the stock zz4 uses 10 to 1 cr and has very poor quench it use a .0501 head gasket and the pistons are down in the block .025.
so why is there no detonation danger here
 
ZZ71s said:
Alright you guys got me good and confused the stock zz4 uses 10 to 1 cr and has very poor quench it use a .0501 head gasket and the pistons are down in the block .025.
so why is there no detonation danger here
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its not that theres no detonation danger, its that its fairly LOW, because of the cam timing, wide 112 lsa and aluminum heads, combustion chamber design, etc that your running, theres no absolute compression level that will induce detonation, where if your at %5 lower your totally immune
fuel octane, air coolant and oil temps, spark advance and plug heat range all effect the results, when you see a chart like these below, they provide a good guide to keep you out of potential trouble, but each combos unique and has a different potential to cause detonation, simply slowing the ignition advance , and changing to a different plug heat range, ,and enriching the fuel/air ratio is sometimes all thats required to run lets say a 8.8:1 dynamic compression in one combo, but a similar one may only tolerate a 8.4 dynamic compression with the same mods
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This is what the project is going to look like 1983 k20 pickup wieghts 8600 lbs has a granny 4 speed with 308 gears the engine is a target master 350 with the pistons down in the block .024 with 10ish dishes the heads are ZZ4 AL with 58 cc chambers the is .028 this would make 10 to 1ish cr and I was thinking I was going to urn the Voodoo 60101.
The idea I had was to use the voodoo 60101 to build power low in the rpm range with the ZZ4s small 163 ports to try to move that heavy truck.
Do I need to choose a defferent cam and lower the CR
What would you do Grumpy
 
ZZ71s said:
This is what the project is going to look like 1983 k20 pickup wieghts 8600 lbs has a granny 4 speed with 308 gears the engine is a target master 350 with the pistons down in the block .024 with 10ish dishes the heads are ZZ4 AL with 58 cc chambers the is .028 this would make 10 to 1ish cr and I was thinking I was going to urn the Voodoo 60101.
The idea I had was to use the voodoo 60101 to build power low in the rpm range with the ZZ4s small 163 ports to try to move that heavy truck.
Do I need to choose a defferent cam and lower the CR
What would you do Grumpy
Click to expand...

the current cam or the voodoo 60101 will work, the voodoo is going to produce a bit more peak hp and be slightly less prone to detonation, but that 3.08 rear gears, are what is really hurting here,if thats a standard muncie trans, if it was my truck, and I wanted a new cam,limited to those two choices, ID be looking for the voodoo cam and a 4.11 rear gear ratio
 

If this is the right specs for the ZZ4 camshaft that you have, the partial reason its running a 10:1 CR without problems would be that the intake closes later by a 11 degrees at 67 ABDC.

This brings the DCR down to 7.95:1
 

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yep that the cam I looked pretty hard to find a cam that favors the exhaust side like that cam and still have the huration and lift I was looking for.
I think the reason for the 308 gears is the Muncie sm465 has a 6.55 first and 3.58 second 1.57 third
 
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