Another mileage build going on. Cam straight up?

Another mileage build going on. Cam straight up?

Joined: April 3rd, 2011, 9:50 pm

January 8th, 2012, 5:48 pm #1

Building a true daily driver 73 Mach 1
Original 2v engine with .020 over flat top hypers.
I've installed a 4R70W and 3.50 gears.

I want to switch to a 4v carb and I will be using EGR so I think I'm going to use a Aussie spreadbore intake from Aus Ford Parts.
My Carb is undecided. I have to have a PVC nipple in the back of the carb base and I want to try to use the Holley throttle position sensor that mounts near the choke. I think an original 4300D uses the same mounting points as Holley so it may be used.


I'm using a Melling MTF-2 cam and my RPM at target speed in locked overdrive at 49mph is around 1500


Cam specs 486/512 lift, 281/296, 106/118 lobe center
sae timing BTC 30 ABC 72 BBC 78 ATC 34 .050 timing BTC -4 ABC 28 BBC 45 ATC -11

So my question is should the cam be installed straight up? +4 or something else?
Last edited by beemerdriver on January 8th, 2012, 5:48 pm, edited 1 time in total.
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Joined: December 16th, 2003, 1:59 am

January 8th, 2012, 7:04 pm #2

with lobe centers of 106*/118* the Melling MTF-2 has an LSA of 112* and has 6* advance ground in

when you say Straight Up are you refering to setting the marks on the timing sprockets being in the '0' position?

~assuming~ all the marks are in the right places, if you were to set the timing sprockets in the +4 position you'd have 10* advance on the intake lobe center from the LSA

i've found that the marks on aftermarket timing sets are not what they would have you believe, '0' is not always zero and +/- is not always 4 degrees. one set i checked 0 was -4*, it was a copy of a retarded emission timing set. other sets i checked the +/- were 2* and 3*, you don't know until you check by degreeing the cam in each position. like Forrest says, you never know what you're gonna get
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IDK if computer sym's generally run as low in the RPM as 1500?

or how accurate they are at projecting Brake Specific Fuel Consumption(BSFC) at low RPM?

w/o any sym data showing otherwise i'd degree it to Intake Lobe Center(ICL) 106* like it's ground and see how the car reacts in lock-up. then you can make an adjustment based on actual rather than hypothetical


there'll be phantoms, there'll be fires on the road... and the white man dancing
Last edited by tinman351 on January 9th, 2012, 1:25 pm, edited 1 time in total.
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Joined: May 20th, 2005, 4:48 pm

January 8th, 2012, 7:12 pm #3

Building a true daily driver 73 Mach 1
Original 2v engine with .020 over flat top hypers.
I've installed a 4R70W and 3.50 gears.

I want to switch to a 4v carb and I will be using EGR so I think I'm going to use a Aussie spreadbore intake from Aus Ford Parts.
My Carb is undecided. I have to have a PVC nipple in the back of the carb base and I want to try to use the Holley throttle position sensor that mounts near the choke. I think an original 4300D uses the same mounting points as Holley so it may be used.


I'm using a Melling MTF-2 cam and my RPM at target speed in locked overdrive at 49mph is around 1500


Cam specs 486/512 lift, 281/296, 106/118 lobe center
sae timing BTC 30 ABC 72 BBC 78 ATC 34 .050 timing BTC -4 ABC 28 BBC 45 ATC -11

So my question is should the cam be installed straight up? +4 or something else?
Never assume a cam is ground the way it should be....and never assume the crank is indexed properly and the timing chain is manufactured correctly.

"Straight up" is a term that refers to the LSA being equal to the ICL. Just as an aside, installing the timing set so that the crank gear is in the 0 position and the gears are dot to dot doesn't mean that it's straight up. The cam can have advance or retard ground into it and even though you put the timing gears in that spot, it could still be advanced or retarded.

To further answer your question, I would degree the cam, then put it on a 106ICL. So if your LSA is 112 for this cam, then it would be installed 6 degrees advanced.

Brent Lykins
B2 Motorsports, LLC






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Joined: December 17th, 2003, 4:14 pm

January 8th, 2012, 7:16 pm #4

Building a true daily driver 73 Mach 1
Original 2v engine with .020 over flat top hypers.
I've installed a 4R70W and 3.50 gears.

I want to switch to a 4v carb and I will be using EGR so I think I'm going to use a Aussie spreadbore intake from Aus Ford Parts.
My Carb is undecided. I have to have a PVC nipple in the back of the carb base and I want to try to use the Holley throttle position sensor that mounts near the choke. I think an original 4300D uses the same mounting points as Holley so it may be used.


I'm using a Melling MTF-2 cam and my RPM at target speed in locked overdrive at 49mph is around 1500


Cam specs 486/512 lift, 281/296, 106/118 lobe center
sae timing BTC 30 ABC 72 BBC 78 ATC 34 .050 timing BTC -4 ABC 28 BBC 45 ATC -11

So my question is should the cam be installed straight up? +4 or something else?
Steady state cruise, it may pull more mpg than the dual plane. Check the wiki for intake pics.
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Joined: October 1st, 2004, 8:05 pm

January 8th, 2012, 11:33 pm #5

Building a true daily driver 73 Mach 1
Original 2v engine with .020 over flat top hypers.
I've installed a 4R70W and 3.50 gears.

I want to switch to a 4v carb and I will be using EGR so I think I'm going to use a Aussie spreadbore intake from Aus Ford Parts.
My Carb is undecided. I have to have a PVC nipple in the back of the carb base and I want to try to use the Holley throttle position sensor that mounts near the choke. I think an original 4300D uses the same mounting points as Holley so it may be used.


I'm using a Melling MTF-2 cam and my RPM at target speed in locked overdrive at 49mph is around 1500


Cam specs 486/512 lift, 281/296, 106/118 lobe center
sae timing BTC 30 ABC 72 BBC 78 ATC 34 .050 timing BTC -4 ABC 28 BBC 45 ATC -11

So my question is should the cam be installed straight up? +4 or something else?
are designed for Thermoquads, not Autolite 4300D, an Autolite EGR plate will not fit, nor a 4300D carb.

I wouldn't use EGR unless it is needed to pass a visual smog inspection. Without EGR you could select a nice manifold like the Edelbrock Performer 2V. But if you must use egr then the Holley Street Dominator recommended by Roo is probably the easiest way to get from point A to point B. If you just gotta use a 4300D, you could bolt a 4V manifold to your 2V heads.
________________________

The advertised duration of Melling camshafts is overstated, making it hard to figure the valve events

An intake centerline of 108 degrees will center the overlap period around TDC. The cam is too small to put the exhaust valve opening or intake valve closing where I would like to put them. This motor will idle rough and rev to 5000 rpm. Don't use too big of a carburetor. That's why I recommended a 600 cfm carb, such as an Autolite 4300A, Holley or Edelbrock.


-G
____________________________________________________________

Pantera Photos | 351C Historic Information | 351C Technical Information

If you use a 351C 4V powered vehicle for a grocery getter ... the eggs aren't going to make it home!
Last edited by gpence on January 9th, 2012, 12:02 am, edited 1 time in total.
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Joined: December 17th, 2003, 4:14 pm

January 9th, 2012, 12:06 am #6

I think it's 204-214 duration @ .050", should be able to balance a nickel on the air cleaner. I remember a slightly used cam on the table at a swapmeet, man said it had a stock idle and that is what he didn't want, he changed out cams.
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Joined: April 3rd, 2011, 9:50 pm

January 9th, 2012, 12:32 am #7

are designed for Thermoquads, not Autolite 4300D, an Autolite EGR plate will not fit, nor a 4300D carb.

I wouldn't use EGR unless it is needed to pass a visual smog inspection. Without EGR you could select a nice manifold like the Edelbrock Performer 2V. But if you must use egr then the Holley Street Dominator recommended by Roo is probably the easiest way to get from point A to point B. If you just gotta use a 4300D, you could bolt a 4V manifold to your 2V heads.
________________________

The advertised duration of Melling camshafts is overstated, making it hard to figure the valve events

An intake centerline of 108 degrees will center the overlap period around TDC. The cam is too small to put the exhaust valve opening or intake valve closing where I would like to put them. This motor will idle rough and rev to 5000 rpm. Don't use too big of a carburetor. That's why I recommended a 600 cfm carb, such as an Autolite 4300A, Holley or Edelbrock.


-G
____________________________________________________________

Pantera Photos | 351C Historic Information | 351C Technical Information

If you use a 351C 4V powered vehicle for a grocery getter ... the eggs aren't going to make it home!
I saw the aussie intake is thermoquad. I could build a frankencarb for the application. I'm OK with that. My main goal is it looks stock 2v with the air cleaner on it, followed by EGR and mileage. I've done so many modifications to the car it's nuts. If you were to look at it without an intimate knowlege of 73 mustangs you would think it's bone stock.
Last but not least, I have a chebby guy down the street. Old Corvettes and I saw a Z28 Camaro and an El Camino. I have no doubt he will test my car. Just want to tune this to be a good performer. I've heard his cars. He's not all that if you know what I mean.
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Joined: February 2nd, 2003, 3:52 am

January 9th, 2012, 2:57 am #8

are designed for Thermoquads, not Autolite 4300D, an Autolite EGR plate will not fit, nor a 4300D carb.

I wouldn't use EGR unless it is needed to pass a visual smog inspection. Without EGR you could select a nice manifold like the Edelbrock Performer 2V. But if you must use egr then the Holley Street Dominator recommended by Roo is probably the easiest way to get from point A to point B. If you just gotta use a 4300D, you could bolt a 4V manifold to your 2V heads.
________________________

The advertised duration of Melling camshafts is overstated, making it hard to figure the valve events

An intake centerline of 108 degrees will center the overlap period around TDC. The cam is too small to put the exhaust valve opening or intake valve closing where I would like to put them. This motor will idle rough and rev to 5000 rpm. Don't use too big of a carburetor. That's why I recommended a 600 cfm carb, such as an Autolite 4300A, Holley or Edelbrock.


-G
____________________________________________________________

Pantera Photos | 351C Historic Information | 351C Technical Information

If you use a 351C 4V powered vehicle for a grocery getter ... the eggs aren't going to make it home!
The 4bbl intake for 2V heads was introduced in mid-1972 on the automatic equipped XA Falcon GT. These cars used an Autolite 4300 squarebore carb. This combo was used through the XB range that ended in 1976. The Thermoquad carb and spreadbore intake was introduced in late 1976 on the XC line of Falcons and was used on both the 351C and 302C. So, there are two intakes, early squarebore 4300 and late spreadbore Thermoquard. I've given or sold several 4300 intakes to guys here in the States. One of my close friends added a Pony Carbs rebuilt 4300 and Aussie intake to his restored H-code 1973 Ranchero and stumped many a car show expert.
Last edited by xafalcongs on January 9th, 2012, 2:57 am, edited 1 time in total.
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Joined: October 1st, 2004, 8:05 pm

January 9th, 2012, 4:40 am #9



those are my toes in the lower picture

-G
____________________________________________________________

Pantera Photos | 351C Historic Information | 351C Technical Information

If you use a 351C 4V powered vehicle for a grocery getter ... the eggs aren't going to make it home!
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Joined: December 16th, 2003, 1:59 am

January 9th, 2012, 1:43 pm #10

are designed for Thermoquads, not Autolite 4300D, an Autolite EGR plate will not fit, nor a 4300D carb.

I wouldn't use EGR unless it is needed to pass a visual smog inspection. Without EGR you could select a nice manifold like the Edelbrock Performer 2V. But if you must use egr then the Holley Street Dominator recommended by Roo is probably the easiest way to get from point A to point B. If you just gotta use a 4300D, you could bolt a 4V manifold to your 2V heads.
________________________

The advertised duration of Melling camshafts is overstated, making it hard to figure the valve events

An intake centerline of 108 degrees will center the overlap period around TDC. The cam is too small to put the exhaust valve opening or intake valve closing where I would like to put them. This motor will idle rough and rev to 5000 rpm. Don't use too big of a carburetor. That's why I recommended a 600 cfm carb, such as an Autolite 4300A, Holley or Edelbrock.


-G
____________________________________________________________

Pantera Photos | 351C Historic Information | 351C Technical Information

If you use a 351C 4V powered vehicle for a grocery getter ... the eggs aren't going to make it home!
good catch George, i missed it after the 4300D reference in the OP. i had just caught a pic of a lunar lander carb too



the AUS spreadbore intake



some have no choke stove provision while others use one, and the AUS choke stove is rumoured to be different than the US version and kinda hard to find. if the intake you get has the choke stove area machined make sure you also get the part that fits there!




there'll be phantoms, there'll be fires on the road... and the white man dancing
Last edited by tinman351 on January 9th, 2012, 1:46 pm, edited 1 time in total.
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