cam in 454 BB question
Thread Starter
Drifting
Joined: Jul 2015
Posts: 1,765
Likes: 254
From: Catlett VA
cam in 454 BB question
I have tried in vain to get info on what cam is in the NOM 454 in my 68 convert from the previous owner. Even sent a self-addressed post card with stamp and a couple check boxes to make it easy for him to reply. No reply. There is much $$$$ invested in chrome and aftermarket intake, carb, headers, etc on the engine, so I can not believe the PO did not upgrade the cam. It launches into full after-burner mode at 3000 rpm and has a discernible "lope" at idle. I really do not want to pull it just to find out the profile. Is there any accurate means to measure the lift and duration by checking how much movement happens on the rocker arms? One of those run-out measuring devices? Or should I just be content to scare the crap out of myself when the engine gets into high rpms? RA
Le Mans Master
Joined: Apr 2001
Posts: 5,436
Likes: 1,253
From: Sarver Pa
2021 C1 of the Year Finalist - Modified
Put a dial indicator on the pushrod or pushrod end of the rocker and measure the darn thing ! At least you will know the lift and maybe can identify it from that.
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
If you have a degree wheel and dial indicator you can use them to find the opening and losing points of the cam at .006, .020 and .050... as well as the Intake and Exhaust Center Lines and lift at the valve or tappet.
Once you have those data points you can calculate everything else about the cam with some very simple math. Then make yourself up a cam card if you like.
Will
Once you have those data points you can calculate everything else about the cam with some very simple math. Then make yourself up a cam card if you like.
Will
Thread Starter
Drifting
Joined: Jul 2015
Posts: 1,765
Likes: 254
From: Catlett VA
If you have a degree wheel and dial indicator you can use them to find the opening and losing points of the cam at .006, .020 and .050... as well as the Intake and Exhaust Center Lines and lift at the valve or tappet.
Once you have those data points you can calculate everything else about the cam with some very simple math. Then make yourself up a cam card if you like.
Will
Once you have those data points you can calculate everything else about the cam with some very simple math. Then make yourself up a cam card if you like.
Will
I had thought of that- I have a degree wheel and a dial indicator is about $20, but I am not sure how to firmly attach it to the cylinder head so the reading is accurate and does not include the indicator flopping around. I may have to fabricate some kind of bracket to fasten to the head. Or... maybe just take jnb advice and not worry about it.
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 780
From: Eustis ( Area 51 Bat Cave ) Fl
Or... maybe just take jnb advice and not worry about it.
I swapped the nice 383 I had because I didn't like the power band for a mild 454...I know basically nothing about the 454 besides it was freshly rebuilt and should have peanut port heads but has oval ports, a super mild lope and would hit afterburner somewhere between 28-32K if the carb was right, but still cruises well and if I didn't let up would melt the tires off,
So I leave well enough alone....
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Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
"If you have a degree wheel and dial indicator you can use them to find the opening and losing points of the cam at .006, .020 and .050... as well as the Intake and Exhaust Center Lines and lift at the valve or tappet."
I had thought of that- I have a degree wheel and a dial indicator is about $20, but I am not sure how to firmly attach it to the cylinder head so the reading is accurate and does not include the indicator flopping around. I may have to fabricate some kind of bracket to fasten to the head. Or... maybe just take jnb advice and not worry about it.
I had thought of that- I have a degree wheel and a dial indicator is about $20, but I am not sure how to firmly attach it to the cylinder head so the reading is accurate and does not include the indicator flopping around. I may have to fabricate some kind of bracket to fasten to the head. Or... maybe just take jnb advice and not worry about it.
We are not very far apart and it would only take about half an hour to measure the cam once you have the pulley's and accy drive out of the way.
Will
Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
Years ago when I was working on my first SBC, I asked a local professional racer and engine builder to recommend a cam. Without a second's hesitation he wrote down a part number. I foolishly asked him what the specifications were and he answered "If I told you, would you know what they meant?". Chagrined and embarrassed, I installed the recommended cam. The engine screamed! I read the spec sheet that came with the cam, and to this day, I don't understand what the numbers really mean. Yea, it's easy to say it's got X amount of lift for Y number of degrees and Z amount of lobe separation, but I haven't got the faintest idea of what would happen if the variables were changed. Too much? Too little?
In order to create a grind profile, every degree of rotation will have to be charted against lift. Is it really that important to know so that you have bragging rights over a guy with 0.005 less lift? Remember, the engine does run great. I'd rather spend my time burning rubber than degreeing a cam.
JMO
In order to create a grind profile, every degree of rotation will have to be charted against lift. Is it really that important to know so that you have bragging rights over a guy with 0.005 less lift? Remember, the engine does run great. I'd rather spend my time burning rubber than degreeing a cam.
JMO