amoosenamedhank

They have race prepped cranks going past 1000hp.

masterofthepuppets99

i believe it was on svtperf that i saw this, but some guy was running a mkviii cast crank and he it literally broke into 5 pieces. he said it wasnt hp that destroyed the crank but excessive rpms. the pictures were brutal!

zero2005

i'm confused, so basically the crank is rock solid? might have chance to pick up some forged pistons and rods for 500. be sweet to toss them into a mk8 4v and boost it. i dont think i'd ever turn any modular beyond 6000-6500 (exception would be a N/A race prepped one). what RPMs was he spinning that crank at before it shattered?

1998Slow 'Stang

I know I'm chiming in late here, but definitely doing this swap soon too. I can get a Mark VIII motor from the local you pull-a-part place for about 150-250 dollars. I believe it to be a 93-96.
The younger (obviously) being an OBD-I design, will all the sensors from the 93-95 motor plug into my stock 98 GT harness? Need to know before I go pull the motor and find out it wont work.

BlackMage

read through this thread man! thats a steal of a deal on the motor depending on the mileage and what is actually on it. my motor was out of a 93 mark. 90% of everything is a direct swap from your 2v onto the 4v. This is a super easy swap for the 96-98 guys. All total i spent $1530 on my swap. The most expensive parts: motor-$350, intake mani-$300, cobra throttle cable-$100, alt -$100, IMRC plates-$50

BlackMage

the mark cranks are junk. u want a 96-98 cobra crank, or one that is built to hold the power..

1998Slow 'Stang

EDIT: I read the thread again, looked on ebay, then re-read the thread and I see that the intake from a 97-98 Mark won't work. : /
I've read it twice, but its got a ton of info so i probably missed something. Lol. 120K on the clock. I read another thread that said the Mark VIII throttle cable would work, can you confirm or deny this? Would a mani off of a 97-98 mark work? I know where I can get one for around $35, and I thought you could delete your IMRC doohickies by gobbing the holes from the rod the butterflies sit on with JB weld?

masterofthepuppets99

for n/a purposes i dont see why the cast crank in the mkvii is junk. i prefer a cast crank since it is lighter than a forged one. i believe the mkviii crank let go at 7000rpms in that thread i read over on svtperf. i spin my mkviii crank to 7k all the time without issue. im puttin down 323hp with 03 heads. im gonna push this block until it blows. but if your going for boost than i do think a forged crank is a good idea.

zero2005

i was thinkin just get a mk8 motor, replace the rods, bearings and pistons with lower compression and boost, but keep the RPMs reasonable. it doesnt take a boatload of rpms to make HP on boost. N/A is a different story. the crank will add another 500-1000, so unless its really needed (my goals with a mk8 would be 600ish on lowish boost).

i'd really like to know the true limit of the crank.

BlackMage

the intake from the 97-98 mark will work just fine. You will need the throttle cable off a 97-98 mark though, or a 99/01 cobra. The IMRC plates do have butterflies valves which can be deleted. I plugged the holes with JB Weld.


i was under the impression he wanted to make good power with boost, which means i would def not use the stock mark crank haha. but yea, and just bolt ons, i wouldnt worry about the crank.