Cam grinding

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As to the 600, heres a scenario
Lets say you told your rebuilder that your engine was pulling 15 inches of vacuum. He might have put a PV in there rated for 13 or 12 or 11inches of vacuum, cuz thats typical;idle vacuum less 2 to 4". But lets say your idle vacuum is actually closer to 12 inches which is still high for a 230*cam, but your vacuum gauge is calibrated wrong.
Now in neutral, your PV is always on the borderline of opening.Then any slight change in engine vacuum will drive the PV into opening. Putting it into gear could easily cause the PV to flood the engine to a stall.
Now I'm not saying your gauge is lying to you, just that there is no way my 230* cam will pull 15inches,at 800rpm. I might be able to pull 11 or possibly 12, if I crank 18*initial into it.
I'm also not saying your PV is wrong.
But I am suggesting its worth a look, and easy to get to and check,and the PV-plug test,will tell the tale.
 
Is that the nasty little Herbert cam you got from me? Deadgum, I knew it was gonna be nasty but it should idle better than that. how much timing you got in it?
 
AJ/FormS said:
If you have 160 psi, with that 230* cam, Ima thinkin your cr is quite a bit more than 9/1, unless the cam timing is way off.
The cylinder pressure, at 9/1 should be around 140psi.
Your cylinder pressure of 160psi reflects a compression ratio over 10/1, and a Dcr of right around 8/1.
So...............Whats up with that? Is it 9/1? or is it 160psi? Or is the cam-timing off?
Click to expand...

His cam is ground on a 106. That will help increase cylinder pressure. My 351M Ford has a static compression ratio of 7.9:1 but it has 155-160 PSI everywhere. Static compression really has little to do with cylinder pressure.
 
Originally Posted by AJ/FormS View Post
If you have 160 psi, with that 230* cam, Ima thinkin your cr is quite a bit more than 9/1, unless the cam timing is way off.
The cylinder pressure, at 9/1 should be around 140psi.
Your cylinder pressure of 160psi reflects a compression ratio over 10/1, and a Dcr of right around 8/1.
So...............Whats up with that? Is it 9/1? or is it 160psi? Or is the cam-timing off?

Alright, let me rephrase that;

If you have 160psi, with that 230* cam, and an ICA of about 65*ABDC , Ima thinkin your Scr is quite a bit more than 9/1, unless the cam timing is way off, and the intake is closing much earlier than the 65*.
The cylinder pressure, at 9/1, AND an ICA of 65*,should be around 140psi.
Your cylinder pressure of 160psi reflects a Static compression ratio of over 10/1, commensurate with a 65*ICA, and a Dcr of right around 8/1.

Hope thats better?
 
Your assuming a lot. Assuming his intake closing event is around 65. WHERE the cams is installed in the engine has a huge effect on that as well and I haven't seen where he said it is. Lots of missing info.
 
RustyRatRod said:
Is that the nasty little Herbert cam you got from me? Deadgum, I knew it was gonna be nasty but it should idle better than that. how much timing you got in it?
Click to expand...

Hi Rusty, yep that's the cam! Finally got it into something, though its not the 340 Cuda I first got it for. It degreed at 106 in the 340 on the stand. Cuda isn't close yet. Took it out to put into the 318 Charger I found CHEAP. FrankenCharger budget build. home hone and rering. Heads were done at my friends engine shop, I did the home port by the sticky. I put the cam in 4deg advanced with the timing set marks. I have set spark timing at everything from 10-22advance. It does run GOOD down the road, sucks at stops. Today I did AJs converter test. Thanks AJ! Engine idles nice around 850rpm. Vac reads 14in at that speed, wheels up and idling ok. Slow apply brakes engine stalls out. brand new Summit 2200 stall conv. Called Summit, they are sending me out a replacement converter, Summit one is out of stock, sending a Boss Hog 2200 at no extra cost. Now I get to pull it all apart again. YAY!
 
AJ/FormS said:
Originally Posted by AJ/FormS View Post
If you have 160 psi, with that 230* cam, Ima thinkin your cr is quite a bit more than 9/1, unless the cam timing is way off.
The cylinder pressure, at 9/1 should be around 140psi.
Your cylinder pressure of 160psi reflects a compression ratio over 10/1, and a Dcr of right around 8/1.
So...............Whats up with that? Is it 9/1? or is it 160psi? Or is the cam-timing off?

Alright, let me rephrase that;

If you have 160psi, with that 230* cam, and an ICA of about 65*ABDC , Ima thinkin your Scr is quite a bit more than 9/1, unless the cam timing is way off, and the intake is closing much earlier than the 65*.
The cylinder pressure, at 9/1, AND an ICA of 65*,should be around 140psi.
Your cylinder pressure of 160psi reflects a Static compression ratio of over 10/1, commensurate with a 65*ICA, and a Dcr of right around 8/1.

Hope thats better?
Click to expand...

When I first got it,This engine blew 155psi before I even pulled it out. It had a miss on cyl8 and only 90psi on that cyl, bad valve. It had a Stock roller cam, worn out nylon cam gear, untouched 1988 318. Trans was blown apart, literally.
 
I bet the new converter doesn't fit it.

2 carbs, both do the same thing.... hmmmm... classic symptoms of a common issue. I get a feeling the answer is in this thread somewhere. I'm a firm believer in do the simple stuff first.

Paralysis by analysis.
 
Oh, oh.
A 230* cam and a 2200TC are not a good match.I think even a 2800 would be a bit shy.Its a good thing you,ve got those 3.91s.
And with the 2800TC, I'll bet it would pull 3.55s pretty easy.
But I'm not convinced yet, that you have a 230* cam in there, so it might all work out yet.
 
If you cannot get that cam to idle at 850 in DRIVE with a stock converter, you got sumffin else wrong.
 
RustyRatRod said:
If you cannot get that cam to idle at 850 in DRIVE with a stock converter, you got sumffin else wrong.
Click to expand...

A faulty converter is all I have left. In the air, when the wheels stop the engine stops. When I am driving, this new converter seems to grab at really low rpm. When I look back to last fall, I believe it idled in gear with the old converter in drive/reverse. I just had drive in neutral also and had to remove the trans to figure out what I put together wrong this spring. After I got it fixed and put it back together, I put a new converter in because I didn't know what the old converter was rated at.
 
rustyratrod said:
if you cannot get that cam to idle at 850 in drive with a stock converter, you got sumffin else wrong.
Click to expand...

yep!!!

An XE268H has 224 at .050 and idles fine with a stock converter even in 318's. Voodoo 268 is 226. XE275HL, 231 at .050, same thing. None of those have an issue in a 318-360 with a stock converter
 

crackedback said:
yep!!!

An XE268H has 224 at .050 and idles fine with a stock converter even in 318's. Voodoo 268 is 226. XE275HL, 231 at .050, same thing. None of those have an issue in a 318-360 with a stock converter
Click to expand...

Just shows how much better camshaft lobe profiles have gotten ,over the last thirty years....Just pay attention to the timing curve,and the idle & transition carb circuits.
 
Have a Hughes 230/236 hydraulic cam in 73 360 Duster...Idles great a 800 rpm...with stock converter or 3500 rpm converter....used either eddy 600 or Holley 750.

Distributor has a ton of initial advance...old MP race distributor
 
coyote42 said:
A faulty converter is all I have left. In the air, when the wheels stop the engine stops. When I am driving, this new converter seems to grab at really low rpm. When I look back to last fall, I believe it idled in gear with the old converter in drive/reverse. I just had drive in neutral also and had to remove the trans to figure out what I put together wrong this spring. After I got it fixed and put it back together, I put a new converter in because I didn't know what the old converter was rated at.
Click to expand...

New converter fixed engine stall in drive.
 
I had Hughes regrind a Magnum cam for me and it looks real good. Not sure who does them for Hughes.

I use Mike Jones when I need a cam… he will do anything you want but his recommendations are usually spot on.

www.jonescams.com
 
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