GT_Bob

Well my friends, all good things must come to an end. My stock GT short block finally gave up the ghost today. I haven't torn it down yet but I'll bet it's a connecting rod or a very unhappy piston. The fact that the rotating assembly has seized is undoubtedly a bad thing. I'll blame it on the dang GTech Pro I've been playing with for the last couple of days. It had nothing to do with the 14psi pulley I put on the KB or the "leaner than safe" tune that I was running on the last pass @ 6k before she let go. Naw, it couldn't have been that.

I knew all along I was pushing it at 11psi, but you only live once. It lasted about 8k@9psi and another 4k@11psi. I'll tell you what though, that friggin sob was dang fast with that 14psi pulley and the "atomic bomb" tune.

After a not-so-thorough search on-line and looking through some catalogs, I was leaning towards a built short block from HP Performance. I really don't have any hands-on knowledge of aftermarket 4.6 short blocks nor do I really have a clue who is considered the "industry leader" when it comes to built 4.6's.

What I want is a sb that will easily handle 14~16 psi of boost and 6k rpm.

Racing fuel is dang expensive and not as readily available as pump gas, (not to mention all you can get out here in CA is 91 octane), so I kind of want to play around with compression ratios and boost levels to find a sort of compromise.

I've built several n/a old school "cam-in-block" engines but I have never messed around with these new OHC's. I'm sure it's not rocket science, but I'm still leaning strongly towards a professionally built sb.

I plan on re-using my factory heads if they look o.k. If not, I'll just do a search here for a good set of aftermarket heads for a boosted motor.

My current brake, suspension, tranny, diff, axle and uni-body set-up is "good to go".

If anyone has any input on which engine builder I should look into or if you have a magic comp./boost ratio I'd really like to hear from you.

GT_Bob

4.6L FORGED COMPETITION STREET/STRIP FORGED SHORT BLOCK (long block available by quote)
New Romeo or Windsor Block (Iron Block, Aluminum Cobra block add $600, Australian Block add $900). Fully Prepped, de-burred and custom Honed for Chrome-faced ring set.
Cobra Forged Production Crankshaft good for 1,000hp [additional heat treat w/micro polished journals, shot-peened and magnafluxed]
New 4340 ULTRA LIGHT FORGED I-Beam Rods with ARP 2000 cap screw bolts
New Forged 2816 alloy pistons (stock, .010, .020 size)
Piston sides and tops are ceramic coated to reduce friction, scuffing and control heat
Chrome faced combustion/top ring for ultimate high cylinder pressure sealing. Precision fit for the application.
Federal Mogul Competition series heat treated Rod and Main bearings
Professionally Assembled, Specification Checked and Balanced For Competition Use
ARP main studs
New COBRA HV Oil Pump with Steel Gears.
$5200.00


This is what I'm seriously considering at this point. The $600 option for the Cobra block is very seductive. Anyone know anything about the Australian block?

SSSShhhhhhhhhhh. Don't everyone respond at once now.



[sm=feedback.gif]

02StanGT

That's going to be more than plenty to handle the boost you want it to. That SB sounds bad-***. As for the Aussie block I have no clue. Have ya tried Googlin' it?

jpmustanggt

Modular Mustang Racing has some good ones!

GT_Bob

MMR 4.6 Monster MOD

*Brand New Cast Iron, current production Romeo or Windsor Block, FULL RACE PREP, de-burred and custom Hone for Chrome faced ringset.

*New 4340 3.543 stroke Forged Cobra Crankshaft, FULL RACE PREP- includes additional heat treat w/micro polished journals, shot peened and magnafluxed at no extra charge

*New 4340 5.933 Manley Pro-series Rods ( These US made rods are shotpeened, magnafluxed and weight matched to bring you the finest I-beam rod available for your 4.6), MMR gives the rod a final deep tempering to increase strength up to 300%

*New Forged 2618 Manley pistons 3.552-3.572 Bore size (High or low compression)

*Total Seal file fit rings with Chrome faced combustion/top ring for ultimate high cylinder pressure sealing(precision file fit to your application, nitrous, blower, turbo or N/A)

*Federal Mogul Competition series heat treated Rod and Main bearings, each bearing is hand deburred at the parting line for perfect fit and oil clearance.

*ARP main stud kit for maintaining correct cap location under the hardest of loads

*Complete Pro Assembly and Balancing for the smoothest, highest revving shortblock available.
401500 $4999


This is Modular Mustangs equivalent to what I'm looking for. I'm still leaning towards the HP sb because MMR wants $1100 more for the aluminum block.

code3GT

Check out VT, DSS and Livernois. The ones you listed sound very good. How much boost are ya gonna run?

GT_Bob

I'm going to run 11psi minimum. At least that is the boost level with 8.73:1 compression that I can get away with using 91 octane. However, I want the sb to handel 14psi with VP 101 when I decide I need to go that route.

GT_Bob

SUPER MODular (SOHC 2-valve GT)
NEW Level 10 Race Prepped 4.6 iron block with PRO-X Forged pistons,1.5 1.5 3mm SS50 U Molly rings with Tri Metal bearings, 4340 Forged H-beam rods with ARP 2000 rod bolts, Forged steel 8 bolt crankshaft. Rotating assembly is balanced to Racing tolerances. Bearing clearances are set and the short block is Professionally assembled in our climate controlled clean room. Includes FREE upgrade to ARP main studs and D.S.S. Main support System.,
4.6 Liter
$3699.95



Another option I was looking at.