hi i have a 96gt with a 97 cobra engine. i drove it for one season and spun a cam. i recently bought a set of comp cams s/c and nos cams. i plan on porting and polishing my heads and intake, building the lower half, and next season a supercherger. my question is, what should i port the heads and intake to, and should i stick with the cobras aluminum block or buy a new cast block. i would like to bore the cobra block to a 5.1L. will the cobra heads bolt up to the cast block.any imput would be greatly appreciated.
4.6 32v help
- Thread starter stang9632v
- Start date
the 97 Cobra heads have insane flow. there really isn't any need to port them other than to match the ports. you can port the intake if you wish, but unless you are going to run a ton of boost, you won't see much of a difference. if you are going 5.1L big bore, get an aluminum block sleeved.
Keep your current block.. You have the aluminum teksid already.. Just get it sleeved for a big bore.
Just put the new cams in and rebuild the 97 internals. The teksid (stock 97) block and stock crank are the best so no need to upgrade them, just have them cleaned
You don't need to port/polish anything, the heads are great by themselves with boost. a .20 bore and 14lbs on some forged pistons+rods, with stock compression will give you enough power
hotmustang331
Active Member
Fixed!!
Thats if you want to do it right. Dry sleeve will work for boost lvs BELOW 17PSI.
Mustangog2003
New Member
Does sleeving make it stronger or something? SO are you actually boring it over what you want it then they put a sleeve in it to match your specs? Please explain sleeving.
i smacked 4 valves and ruinrd 2 pistons when the cam seized. are there pistons i can get that will have clearance so that wont happen again? also what is the differance between wet and dry sleeves?will there be a big differance in power between the stock pistons and the 5.1 pistons when i supercharge it?
also does anyone know a good place to get a good tune for the xcal 2.
also does anyone know a good place to get a good tune for the xcal 2.
Mustangog2003 said:
The sleeves are pressed into the block to form the cylinder, then honed true. Otherwise, the steel rings would gall the aluminum, and you'd have major blowby issues. Installing the big bore kit is just pulling the factory sleeves, boring the block, then installing new larger sleeves to fit your desired bore.
stang9632v said:
Most aftermarket pistons will have larger than factory valve reliefs, but you should still check piston to valve clearance. A dry sleeve is supported by the block from top to bottom. A wet sleeve is supported typically at only the top and bottom, to allow coolant flow around the cylinder, thus keeping the temperature under control better in the combustion chamber. It's very beneficial in a forced induction application because of the higher heat associated with boost. Many turbo diesel engines utilize wet sleeves for that very reason.
You should see a fairly good boost in power with the 5.1L kit. More displacement = more room for air and fuel. Even better when boosted. Can't help with the XCal issue, have no knowledge in that area.
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