High compression blues.

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hosehead said:
Man, the Oregonian's here are really not digging my local cam grinder joke.......:poke:
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Oregon Cam Grinding started in Oregon. Then, IIRC he was down off of highway 14 for a while and then ended up at his current location.

I first met Kenny probably 1981. He had an AWB mustang that had a saying on the trunk: "Special thanks to clean living and self denial". A great quote.

Plus, he and his wife had a cute little dog they brought to the office. I forget his name. Damn nice dog.

Kenny and his family are damn good people.
 
yellow rose said:
Oregon Cam Grinding started in Oregon. Then, IIRC he was down off of highway 14 for a while and then ended up at his current location.

I first met Kenny probably 1981. He had an AWB mustang that had a saying on the trunk: "Special thanks to clean living and self denial". A great quote.

Plus, he and his wife had a cute little dog they brought to the office. I forget his name. Damn nice dog.

Kenny and his family are damn good people.
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I seem to have a knack for reading people fairly well and this was kind of the feeling that he gave me after some conversations. Of course conversation nothing of personal life, just Cam profile and racing. I know Ted and Ken are Ford guys, but way more important to me they are friendly and helpful. Also they race their stuff and talk from experience. Lots and lots of experience. Okay so Ken up sold me on some lifters that I do not regret one minute going with. Said something about Barrel lifters or something?
 
Long story short, I tried to "flood" the ping outta a hi-comp engine, with cams, carbs, timings, head gskts, heads. When pulling pistons to trim the domes, I discovered only one piston with detonation damage. Sanded the "sharp" edges off my valve reliefs, and any other edges, re-assembled, without trimming pistons, that #@$%#@ ping was gone. Check alternatives imho. 1 vacuum leak could do it.. good luck. Bore scope may be of help.
 
hosehead said:
Tim from Bullet's custom grind:
247/251@50
546/557 lift
109 lsa
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Close to my solid roller !! --254/260, .620/.628 @ .050----------1/6 rockers. Heads flow 352@.600, but don`t go up much from there. Docile as all get out on the street (no traction), turns sideways w/ throttle. Hope to get it to the strip this summer, w/ a few more miles on it first.
 
hosehead said:
Tim from Bullet's custom grind:
247/251@50
546/557 lift
109 lsa
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My small block in my D-50 is 10.9 comp. with a 255/266 @.050 cam with 195-200 lbs cylinder pressure. Mine was built for 91 octane but have never ran anything but 93. It has never detonated. I run my timing at 35*.
 
yellow rose said:
Is that the only one who got back to you? And is that grind to keep the CR you have now?
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I briefly spoke with Jim at racer brown. super nice guy. He didn't really want to get into grinds until I knew how deep in the hole the pistons are. I talked to the machine shop today and found out that the deck was only surfaced, not cut so I'll probably call him back tomorrow.
Also, my colder plugs came in today so I'm going to put those in now.
And yes, the bullet cam would be made to work with my existing compression ratio. Tim thought it would really wake up my 440. Super cool guy who took the time to explain everything. I'll probably decide something after I drive the car with the colder plugs.
 
hosehead said:
Anytime it's at high rpm. Tim at Bullet explained this as the lack of duration with my high compression.
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If You could, please post the Icon part# for Us.........................................
 
OK, those are supposed to be 440 3x2bbl 10.5:1 slugs, you drop ~7cc for the heads and gain ~3cc for the Felpro's so they come up with ~10.91:1.
 
I'm still struggling with your gauge pressure.
The heads are listed at 78cc
... gasket maths out to 10.9cc
.....IC-968 eyebrows at 4.4cc
estimating the deck at -1.1cc
Totals.........................92.2cc

So with a 4.35x3.75 having a swept of 913cc, then
(913+92.2)/92.2 =10.9Scr I get that this is reasonably possible. And probably correct.
But now with that 292/296/108 cam in at 107* for an ICA of 73*
The Wallace kicks out; 10.9Scr/8.0Dcr/160psi/152VP
and IMO, no matter how badly the install might be, it could never approach 200psi....and still run. Even in at 102* the pressure has only climbed to 170.
Soooooooooo, am I out in left field here?

The reason I ask is, if you slam a bigger cam in there and the Wallace is right, and the pressure falls to say 155, ......... how is that gonna translate to the trap speed?
I mean many of us SBMers are running 185psi with aluminum heads and no detonation. A few, or several are pushing 200 or better, still on pump gas...according to a survey I took many months ago.

So, if the Wallace is correct..... is there some other factor, that could be causing the light-ping..or the sound of it, or a sound LIKE it??
I have to think of the possibility that it might be pre-ignition, because that can occur at almost any pressure. and I think someone touched on that already.Yeah that was Inertia in post 78

Respectfully,AJ
 
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AJ/FormS said:
I'm still struggling with your gauge pressure.
The heads are listed at 78cc
... gasket maths out to 10.9cc
.....IC-968 eyebrows at 4.4cc
estimating the deck at -1.1cc
Totals.........................92.2cc

So with a 4.35x3.75 having a swept of 913cc, then
(913+92.2)/92.2 =10.9Scr I get that this is reasonably possible. And probably correct.
But now with that 292/296/108 cam in at 107* for an ICA of 73*
The Wallace kicks out; 10.9Scr/8.0Dcr/160psi/152VP
and IMO, no matter how badly the install might be, it could never approach 200psi....and still run. Even in at 102* the pressure has only climbed to 170.
Soooooooooo, am I out in left field here?

The reason I ask is, if you slam a bigger cam in there and the Wallace is right, and the pressure falls to say 155, ......... how is that gonna translate to the trap speed?
I mean many of us SBMers are running 185psi with aluminum heads and no detonation. A few, or several are pushing 200 or better, still on pump gas...according to a survey I took many months ago.

So, if the Wallace is correct..... is there some other factor, that could be causing the light-ping..or the sound of it, or a sound LIKE it??
I have to think of the possibility that it might be pre-ignition, because that can occur at almost any pressure. and I think someone touched on that already.Yeah that was Inertia in post 78

Respectfully,AJ
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If basic formulas were infallible, there would be no need for drag racing(or any other testing).
 
hosehead said:
Icon IC968. By their calculator, I have 10.9-1 compression.
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I missed it, do u have alum. heads ? 10.9 aint too high if u do. Did u call hughs engines/ they deal w/ problems like this about daily. PM sent.
 
famous bob said:
I missed it, do u have alum. heads ? 10.9 aint too high if u do. Did u call hughs engines/ they deal w/ problems like this about daily. PM sent.
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I have alum heads and run California 91 Octane. I’ve got 9.7:1.

I’m on the edge of pinging. On a 95 deg day going up a steep steady mountain I had slight pinging (sounded light). I backed timing a deg, plugs, carb adj, and all good.

Imho, that “one full point compression increase with aluminum heads all else equal” is a false general statement. Especially with more street friendly smaller cams.
 
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autoxcuda said:
I have alum heads and run California 91 Octane. I’ve got 9.7:1.

I’m on the edge of pinging. On a 95 deg day going up a steep steady mountain I had slight pinging (sounded light). I backed timing a deg, plugs, carb adj, and all good.

Imho, that “one full point compression increase with aluminum heads all else equal” is a false general statement. Especially with more street friendly cams.
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WORKING FOR ME !
 
autoxcuda said:
You’ve got a step or two bigger cam that hosehead has.

You run the garden variety 91 octane California swill?
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91 unleaded , no ethenal. There are 3 stations that I know, of that sells no ethanol gas , w/in 10 miles of me. Wish we could get 93 , like a lot of the rest of the country.
 
hosehead said:
Icon IC968. By their calculator, I have 10.9-1 compression.
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Here's a problem, I cc'd a '75 or '76 440 with a set of OE 10.1:1 cast slugs in it, with the Mopar shim gasket@.017" & untouched 452 heads. It hit 9.98:1 when I was done.
Not a surprise as some of the late casting chambers were a tad bigger than the "906" era chambers by ~3cc. But I also measured a piston to deck ht. of .048", the .017"
gasket, and a chamber depth of ~.130".......that's .195" from crown to quench/squish surface.
1) the 440 6bbl slugs are .076" taller comp. distance.
2) the Trickflow heads quench/squish is .130" lower
3) That's .206" less room than You'd have w/10.1:1 slugs and You only had room for .195"!!!
4) You've only added .020"-.025" with the Felpro at best. that leaves You with ~.010" head to piston?!?!?!?
5) I think the 440 6bbl slugs were "under advertised" because.......a .030" over 440 needs 100.38cc total chamber vol to get 10.1:1, subtracting .076" @bore=-18.5cc +
the 4.4cc=14.1cc + ~3.5cc for the thicker gasket=-10.6cc that would calc. to 11.17:1.............but wait! the heads are down 10cc...a -20.6cc, thats 12.45:1!!!!!!
If someone sees a problem with this please point it out...........................................comp.ht. 10.1:1 1.991",....comp.ht. for the OP's 2.067"............................
 
To add, even going only 7cc down for the heads that is still a tick over 12:1, unless the machinist milled .030" off the pistons to -0- deck 'em..........................
 
I get your math.....
And that would bring the pressure to at least 190/197 with the cam in at 104*,as calculated by the Wallace.
And if the Wallace is correct,

at 12.80Scr it predicts .065pop-up,compared to your .048
at 12.45Scr it predicts .056 pop-up
at 12.10Scr it predicts .045

so you may be on to something; that's Killer work, right there
 
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