is there a differance between 32v and 16v bottom ends
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The stock bottom end on GTs and pre-'03 Cobra's are all the same, basically, minus a little bit different piston to equate for the difference in compression, and the forged vs. cast crank. '03 and up Cobras are much different.
What do you mean a "cast" bottom end? You mentioned "heavy duty" pistons and rings, for which I'm assuming you meant forged, and you also wanted a forged cobra crank, so that would leave using cast connecting rods...why would you do a thing like that?
An all forged bottom end with 11.0-12:1 compression with mach1/cobra or fr500 heads would be a good N/A motor.
What do you mean a "cast" bottom end? You mentioned "heavy duty" pistons and rings, for which I'm assuming you meant forged, and you also wanted a forged cobra crank, so that would leave using cast connecting rods...why would you do a thing like that?
An all forged bottom end with 11.0-12:1 compression with mach1/cobra or fr500 heads would be a good N/A motor.
nickthegenius
Active Member
ChrisWeil said:
I think he meant the Cobras have aluminum blocks and GTs have a cast iron block. Could be wrong. BTW, as far as forged components go, the GT crankshaft is actually fairly strong (up to 500hp or so). Its the rods and pistons you need to worry about.
ChrisWeil said:
And where would one find FR500 heads?
The rods on everything but 03/04 Cobras are some powered metal construction. I believe the rods on the N/A 4V engines are a bit stronger though to deal with the higher redline.
Forged pistons and rods in an aluminum block is the way to go. The forged crank isn't as necessary unless you're making insane amounts of power, the GT crank is a pretty good unit.
A plus with the aluminum block is the ability to do a big bore setup.
Forged pistons and rods in an aluminum block is the way to go. The forged crank isn't as necessary unless you're making insane amounts of power, the GT crank is a pretty good unit.
A plus with the aluminum block is the ability to do a big bore setup.
4v block is aluminum and the 2v is iron.
the rods are stornger due to the increased rpm range. the pistons are the same but with a different cc's. the thing that will let go in a 4.6 first is the rods. I had a motor come to me yesterday with a big hole in the side of the block. the pistons are ok but if you are going with a power adder then definately go with forged internals. about the crank they are rated to 500hp but I have yet to see a broken crank. If anyone has seen one on the internet put a link up. I would like to look at it and see what all it has broken and what it took 2 break it.
the rods are stornger due to the increased rpm range. the pistons are the same but with a different cc's. the thing that will let go in a 4.6 first is the rods. I had a motor come to me yesterday with a big hole in the side of the block. the pistons are ok but if you are going with a power adder then definately go with forged internals. about the crank they are rated to 500hp but I have yet to see a broken crank. If anyone has seen one on the internet put a link up. I would like to look at it and see what all it has broken and what it took 2 break it.
hotmustang331
Active Member
While on the subject, what exactly is the rev limit of the 4V engines?( I know red line is 6800 but where the limiter actually hits)I believe 2V is 6250(red line at 5800) so basically its ONLY the rods that hold back the RPMs?And how many RPMs will the stock GT crank take?
ok here is the deal i just wanted to know if there was a differance between the aluminum and the iron blocks because i wanted to build a iron block with the 32v fr500 heads with some extra strong lower end pistons with the cobra crank to go in my 01 cobra i am not interseted in supercharging or n2o i just want a naturely asperated 32v that can withstand a whole lot of abuse 
CATMACH
New Member
My Mach hits the rev limiter just after 7000. I think its 7050. Autos have a lower limit, about the same as GT's I think.hotmustang331 said:
thebeastum said:
No, it isn't that simple. Sure they should bolt up...but there is a hell of a lot more that goes into the swap than just swapping heads
bdcardinal said:
http://www.gefracing.com/Merchant2/...&Product_Code=M6049D46&Category_Code=46ENGINE
Those are just 2v heads.
http://www.seanhylandmotorsport.com...id=96&osCsid=2e2ed2877c1d91383f03894d77cdd247
those are FR500 cylinder heads. they are like 8grand for the port job, plus you need the core
those are FR500 cylinder heads. they are like 8grand for the port job, plus you need the core
SHM is the king of all ripoffs. $260 for an aluminum driveshaft 
