Donor 4.6DOHC swaps SVT/blown

russ jerome

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Keyword search's net little info:

If you were searching E-bay and boneyards for trashed
Mustangs what are ideal donors for our cars (mine is a
1997) for motor swaps, supercharged and NA. Our lower
ends would apear to be weak links, our block seam like
ideal keepers for forged swap topped off with blower.
 
our cars have essentially cobra motors in them. build what you have. build the bottom end.freshen up the top end,new cams,act. throw a blower on top with some engine tuning there you have it.
 
Although there is a lot of contradictory posts here (have
read thru each page) I am lead to believe our Marks have
cast cranks and the Mustangs forged?

I end up drag racing everything I own so a stout lower for
forced induction or a wet shot would make me sleep better
if Im pulling the whole motor (175k all original!).

I have freinds who own salvage yards, just looking for the
best model years should I find more than one donor for
a bench build or direct swap low milage swap.
 
You're not making much sense, man.

Thank you, yes I wanted to know about the cranks from
Muscrat to Lincoln as well.

Lets start over:
If "you" had every production year and model DOHC 4.6
laying in front of you what single year/model motor would
"you" use to repower your 1997 Lincoln Mark8. Forged, best
heads,bolt in for your car plug and play electronics.
edit:
http://home.pon.net/HUNNICUTT/history_svt.htm
 
DOHC lifeline for the Marks....

93-95 MARK VIII: B heads, Cast Crank, Old Style Valve Springs
96-98 Mark VIII: B heads, Cast Crank, Beehive Valve Springs
 
i have a teksid block that would make a perfect builder, cheap money! its just a block and mains.
 
I would get a 04 cobra long block to start. Its forged and has manley rods also good heads " C ". As for building the mark Viii motor Its a good place to start however the heads do limit the use of many aftermarket mustang parts like blowers and inter coolers. If I were to build a motor on a budget I would get forged pistons and rods and keep the stock cast crank. Use the money saved on the crank and get a set of C heads and intake. That would leave more options later on. I've not heard any talk that the cast crank is an issue with these motors, its the rods and pistons.
 
If you are rebuilding a motor and go to the expense of replacing rods and pistons, then you really have no reason to chince on another $350 or so for a forged crank. You can save money by using the "C" heads with their existing cams and slight bowl port just to clean up rough spots. If you don't SC then spray it. I will agree however that there are only occasional crank breaks with the CI ones.
 
I agree with the boss....Even on an economy build 300 for a good used forged crank is cheap insurance for that much work.
 
If you are rebuilding a motor and go to the expense of replacing rods and pistons, then you really have no reason to chince on another $350 or so for a forged crank. You can save money by using the "C" heads with their existing cams and slight bowl port just to clean up rough spots. If you don't SC then spray it. I will agree however that there are only occasional crank breaks with the CI ones.

What he said except use the Mark cams over the C head cams.
 
What he said except use the Mark cams over the C head cams.

I know this is an old thread but why would you say to use the Mark cams over the cobra cams. Compared to the Mark intake cams (184 deg dur), the 99/01 intake cams have 16 degress more duration the 96-98 intake cams have 20 degrees more. The 03/04 cobra (and marauder, navigator, avaitor and mach 1) cams have the same duration as the Marks at 184 degrees. The exhaust cams are the same in all 4vs.

I agree with the boss....Even on an economy build 300 for a good used forged crank is cheap insurance for that much work.
Teh cast crank will withstand a lot of power and is a few pounds lighter than the forged cranks. Cast cranks are used in 12 to 1 compression NMRA factory stock and pure street engines that are seeing 8500 to 9000rpm so I think they will hold up nicely. BTW, have you ever heard of a cast crank breaking?
 
I know this is an old thread but why would you say to use the Mark cams over the cobra cams. Compared to the Mark intake cams (184 deg dur), the 99/01 intake cams have 16 degress more duration the 96-98 intake cams have 20 degrees more. The 03/04 cobra (and marauder, navigator, avaitor and mach 1) cams have the same duration as the Marks at 184 degrees. The exhaust cams are the same in all 4vs.

You seem to have a lot of knowledge on these motors(more then me) and I have spoken to you about cam selection on the corral. All the info I have found was the Mark VIII intake cams have the same duration as the 96-98 Cobra cams but are just ground 3* retarded.
 
Yeah the stock cast cranks have been said to hold a whole lot of power. I haven't read any write up that has see a cast stock crank break. Thanks na svt for posting. that's what I was saying earlier. Save the money and keep the crank. Thats my plans when I build my back up engine. 03-04 rods, pistons and head studs. It should be good to go with alot of power adder. Rear turbo set up. Hope to post up this winter.
 
Yeah the stock cast cranks have been said to hold a whole lot of power. I haven't read any write up that has see a cast stock crank break. Thanks na svt for posting. that's what I was saying earlier. Save the money and keep the crank. Thats my plans when I build my back up engine. 03-04 rods, pistons and head studs. It should be good to go with alot of power adder. Rear turbo set up. Hope to post up this winter.

I have to say that I was not a believer in rear mount turbos. However, one of my friends installed one and holy crap, I now believe.

I have one suggestion though, do not go with 8.5 to 1 compression, it will kill pre boost torque and you'll hate driving the car. You can safely run 9.5 to 1 compression with FI and it will help the turbo spool quicker. Yes, 8.5 to 1 compression engines can make a lot of power with turbos, but 9.5 engines will make more power and are a lot more fun to drive.

We've found when going with 8.5 to 1 compression the power is down about 50rwhp/50rwtq and at the same boost levels.
 
Thats good info na svt. First set up will be with the stock motor, maybe 8ish boost. I'll see how it goes.
 

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