pi head swap vs 4v swap

[Mustang Mark]

so by next winter i plan on replacing my wheezy npi 2v with either a pi engine with high compression, or a 4v that i pulled out of a mark 8 last summer.

either engine will have new rings and bearings installed along with any other required parts.
long tubes and an o/r x pipe will be on whatever goes in
the worst part about the 4v is i will have to change all of the timing components on to an iron 2v block since 2 of the ears broke off of the teksid
what would be the easiest/cheapest to get around 300rw N/A?
i know the 2v would at least require a set of cams and full bolt ons, so since i already have the 4v should i just rebuild it and swap it in?
btw i dont currently have a pi engine or heads.

 

[Mustang Mark]

sooo nobody cares to share their opinion on 2v vs 4v?

 

[Mystic SVT]

well, since you already have the 4v B-heads then I'd probably go with the 4v swap instead. You will have to find a 96-98 cobra intake and swap out to cobra cams if you plan on reaching your 300hp goal. It won't be that easy though, the 4v B-head motor will need lt's, shortrunner intake, and imrc deletes since your gt computer won't be able to actuate them.

 

[Mustang Mark]

are the mark 8 intake cams and intake manifold really that bad? i know the engine has about 15 less crank hp than the cobra but i would assume its mainly from the super restrictive factory exhaust with 3 cats and 3 mufflers

im not dead set on 300rw but i would be happy with anything 270rw and up

 

[duff daddy]

NPI block, PI heads ported and a set of 270s and you will have 300 wheel. That was my old set up. It will be alot easier, alot cheaper and simpler.

If you want take taht Teksid, toss everything but the short block in the trash. CLean the block and get a new rotating assembly. put some PI heads on it and have a go at it.

 

[Mustang Mark]

actually the teksid block i have is junk. i was thinking (if i keep it a 2v) ill probably use the mark 8 pistons with unported pi heads with a set of 270s or mhs bullet cams

 

[duff daddy]

you have to notic the mark pistons if your going to use them with 270's

 

[gtvertman44]

You'll want to go PI in my opinion. Nomatter what, you'd have to do cams / intake / computer work to get the 4v at the power level you want (and even more than that to be honest). Although you'll have to work the PI setup as well, it'll be a less complicated change-over. Find somebody who wants the Mark VIII setup that you have and find yourself a PI motor. They're all over the place - I bought one COMPLETE for $400 two summers ago. Then all you have to do is work the heads / change out the cams before throwing some bolt-ons at it and you'll be right where you want to be. Don't do what I've done in the past and just go with what's laying around - as tempting as it may be, it can sometimes run into GIANT headaches and halfway in you'll realize that you should have just started from scratch with the right stuff. Hope that was helpful.

 

[Mustang Mark]

well i picked up a complete pi engine for $130. going to tear into it next weekend. my plan is to fully rebuild it with new every thing except for the crank, block, and valves. fly cut 12:1 compression manely pistons, mmr rods, stock crank, long tube headers, mhs bullet cams (thinking stage 3 pi's) and possibly ported heads

 

[duff daddy]

good luck we will see if you follow though...

 

[Mustang Mark]

any idea how much compression i can run on 91 octane pump gas? my gf's dad (who is helping me build the motor) doesnt want to go higher than 11:1

 

[duff daddy]

lower then 11. in the area of 10.5. its more of a question on the quality of fuel.

 

[Mustang Mark]

okay looks like ill be ordering npi dish pistons. thanks duffy

 

[duff daddy]

I ran NPI bottom end and 270's in PI heads for a while.