Motor Swap Help

[voidfinger]

ok guys, I've finally got a strait motor lined up for my car. Thanks to one of our very cool members.
its out of a 97 Mark 8 and has 80k on the clock.

To get it to :thumb: specs i have a set of 98 cobra cams to go in it. I got a budy that is selling the intake off his 97 cobra so i'm gonna snatch it up.

Now Comes the questions lol

I know that I'm gonna have to get a tuner to tune my gt computer for the cobra motor.
I'm using the gt computer and wiring b/c i'm keeping my auto trans
The motor is coming with the wiring and computer from the mark so should i use it? Will it work?
What would i have to do about a throttle linkage b/c i heard that you can't use the gt one.

Is there anything else that I'm missing in terms of other stuff I'm gonna have to get or need to mod to work? please help me out guys.

Mitchell

 

[Bluesn95]

I don't know what to tell you but I'm pretty sure that theres more. I think that you ac lines will have to be modified of get some off of a cobra. I think you'll also have to buy an 8 bolt flexplate.and you'll have to redo you're fuel lines because its not likely that your existing fuel lines will be in the same place as on the 4v.

 

[voidfinger]

I'm not sure about the ac lines but if push comes to shove I'll do the FRPP AC delete thing. The Mark 8 is a six bolt automatic flex plate and I'm using my auto which is the same thing from mark8

Now with the fuel lines are you talking about the hard lines that connect to the fuel rail or the fuel rail itself? The motor I'm getting is complete so its coming with the fuel rail and the injectors and such.

Thanks, I didn't even think about the ac or the hard lines... I always thought that the acc. drive stuff like ac and power stearing and all were the same as the 2v ... guess i could be wrong.

 

[reivaxtorres]

you can either replace the entire engine harness and ECU with the mark viii one, or you can keep the GT ECU and harness.

Pros for Mark VIII:
it will pretty much be a direct harness/ecu swap
you will be able to keep the knock sensors
you will have the harness for the IMRC's
you will have the harness for the smog pump

Cons:
dunno if the rest of the GT harnesses will work (tail lights, fuel, etc)

Pros for the GT harness/ECU:
you dont have to mess with any of the wiring routing.

Cons:
no more knock sensors
you gotta find a wire to wire up the IMRC's, or do an IMRC delete
you gotta lengthen the wires for MAF, and maybe a few others




as for the fuel rails, i think the rails themselves are the same, its just the hose that connects the two that are different, the rubber hoses. you could prob just get away with using custom length braided lines, or maybe trying to make the mark viii ones work


dont forget the smog pump. dont know if you want to keep it or not, but the 96-98 and the 03-04 DOHC engines used it.

 

[nemoxii]

Just a few points to ponder on V. I also found a Mk VIII and was thinking of doing the same thing. My opinion...opinion being the key word...build the Mk VIII. Cams and intake are a great start...but you've got a working engine in your car which puts you at a great advantage, imho. You can drive your car and , well, enjoy it while you actually build a great baseline motor. My first step IF I were to do it would be to tear it down and scrap the rotating assembly thats in it, cause its the same one thats in our car with the nodular iron crank, shitty connecting rods, and I *believe* hypertonic pistons (which have a nasty habit of shattering in extreme builds). So if you ever planned on going past the 400-450 hp mark, a forged bottom end is going to be a great peice of insurance. Would that stock block see past 450? probably, question is for how long. When you sit down and look at all the numbers, its a great swap..if your not looking for a whole lot more. I think the Mk VIII was rated at 290...with the cobra cams and intake its like 305 (again I think, working off the info I could find around the internet so take it for what its worth). So really, you could build your 2v to make those numbers (yes it would cost considerably more, I know) so the real question is how happy are you going to be with around 300 HP at the fly wheel? If your like me you'd be happy for about a week before you wanted more. Personally, I would sink the money into building up that short block, then throw it all back together with what you've got and put it in your car knowing that yeah you might be at 305hp, but when you want to put on worked over heads with more agressive cams and, dare I say, a blower, you can sleep easy knowing you've got the bottem end to handle it. Just my .02. I know the mighty dollar is the great deciding factor (for me at least) and in a parfect world we'd all be driving around with forged rotating assemblies and 500+ hp in our daily drivers. I just think saveing up for a year and spending $2000 on a rotating assembly that will last for the long haul is a more prudent decision.

Now I'll step off my soap box...

Good luck with the swap, I'm actually really excited to hear how it goes. If you do go ahead and do it, you should toss up a write up. I know I'd love to see how it all worked out and it'd be a great read to see if this is something I would even be interested in doing.

Adam

 

[voidfinger]

I'm thinking since my 2v is gotten right at 200k on the clock and its not the healthiest beast in the stable. I'm just gonna get the mark motor and throw on the cobra intake and the cobra cams and call it done for the motor there. In the future though, I am thinking of a high cr motor with a healthy shot of n2o

Now I saw in the New MM&FF that Eagle has come out with a rotating assembly that is for the cobra... it has a -2cc flat top piston that supposedly has a 13.1 CR and the CI comes in at 297. Then i would throw on a 200 wet shot with a set of ported heads/ custom cams/ and shortened intake runner.

This would all come after it is no longer my DD.

For right now I have a 64 stepside C10 pick up I'm gonna start restoring and making a turbo 350 four bolt main motor out of it :thumb:

Now i'm wondering if the mark 8 computer is similar to my computer and if it could be used with a scal 3 or whatever? If so i would definitly use the mark 8 wiring and computer. IF it worked with the rest of the stuff. That way the shift point would already be done up in the tranny and what not. Keep it coming guys.

 

[Bluesn95]

I'm pretty sure that with 13:1 cr you wouldn't be able to run pump gas. An the pistons that are in the mark v are hypereutectic and they're actually good pistons they just aren't good for spray or an insane amount of boost.

 

[voidfinger]

Unless there is a difference between the 5.0 and the 4.6 I probably can with a tune and 93 premo. My dads 5.0 we built has 13:1 and runs ok with the 93 but screams at 100 octain. Yea the pistons aren't that bad but the rods are lol.