Question about 4v B-Heads
06-02-2011, 08:07 AM
#1
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Question about 4v B-Heads
I am trying to get everything together to do a 4v swap, i have a compltete 93 mark 8 motor, i have purchased a 98 cobra intake, but now im hearing things about the valve springs, can i put 98 cobra beehive valve springs on 93 mark 8 heads, and if so whats involved?
06-02-2011, 11:52 AM
#5
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cams are the same from 93-98 in the Mark VIII's.. the only difference is in the 96-98 cobra the intake camshaft was different, and is the ones u want. the rest of the camshafts from other 4v motors i wouldn't even bother with.
06-02-2011, 07:04 PM
#6
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I read a post from another site that said the valve stem seals were different, I confirmed this with Ford, but I'm wondering if as long as I change seals and valves I'll be OK, if anyone knows anyone who has done this first hand please ask if I'm right
06-03-2011, 02:34 PM
#7
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They are NOT the same heads. The 93-95 B heads have a swirl dam in the combustion chamber between the 2 intake valves. The intake flow is much lower if left stock.
The valve seals are different as the guide tops are different.
You will need to swap both the springs and retainers from a 96 or newer set of heads. All 4V heads other than the 5.4 Cobra/Shelby used the same parts.
To be completely honest, its a very disappointing swap. A stock PI motor with cams will make the same HP with a ton more torque. Early B heads are the same as later once ported, but stock they leave a lot to be desired. If you are intent on a 4V swap then get a set of 03 or newer heads with a Mach intake (its better than the 99-01 cobra intake) and a set of 96-98 Cobra cams. Thats worth about 50RWHP over the Mark motor.
06-03-2011, 05:03 PM
#8
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They are NOT the same heads. The 93-95 B heads have a swirl dam in the combustion chamber between the 2 intake valves. The intake flow is much lower if left stock.
The valve seals are different as the guide tops are different.
You will need to swap both the springs and retainers from a 96 or newer set of heads. All 4V heads other than the 5.4 Cobra/Shelby used the same parts.
To be completely honest, its a very disappointing swap. A stock PI motor with cams will make the same HP with a ton more torque. Early B heads are the same as later once ported, but stock they leave a lot to be desired. If you are intent on a 4V swap then get a set of 03 or newer heads with a Mach intake (its better than the 99-01 cobra intake) and a set of 96-98 Cobra cams. Thats worth about 50RWHP over the Mark motor.
The valve seals are different as the guide tops are different.
You will need to swap both the springs and retainers from a 96 or newer set of heads. All 4V heads other than the 5.4 Cobra/Shelby used the same parts.
To be completely honest, its a very disappointing swap. A stock PI motor with cams will make the same HP with a ton more torque. Early B heads are the same as later once ported, but stock they leave a lot to be desired. If you are intent on a 4V swap then get a set of 03 or newer heads with a Mach intake (its better than the 99-01 cobra intake) and a set of 96-98 Cobra cams. Thats worth about 50RWHP over the Mark motor.
Now, the stock PI/cammed motor, I am not so sure about. I had a Mark VIII swapped 96 GT and a bolt on, pi swapped 98 GT.
The 96 was bone stock down to the exhaust. The 98 had LT headers, ORH, flows, 3.73's, UDP's, and a CAI. The 96 absolutely smoked the 98.
06-03-2011, 07:50 PM
#9
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Join Date: Jan 2009
Location: Florida
Posts: 570
The 93-95 Mark intake manifold makes more power than the 96-98 Mark intake, but it won't fit in a Mustang. Trust me on the cammed PI 2V smoking a stock Mark B motor, been there done that (and I probably own more B heads than anyone else on the planet)
BTW - working up a set of early B heads right now for 8500RPM and 35lbs of boost on straight alcohol. Heads got Timeserts on all 8 cylinders, Manley beadlock valves, and a set of $700 valve springs to handle the abuse.
BTW - working up a set of early B heads right now for 8500RPM and 35lbs of boost on straight alcohol. Heads got Timeserts on all 8 cylinders, Manley beadlock valves, and a set of $700 valve springs to handle the abuse.
Last edited by nickmckinney; 06-03-2011 at 07:54 PM.