I'm looking at the mmr short blocks and I was wondering are there any disadvantages of running the cobra cast iron block besides the extra weight?
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whipple HO SC,FRPP springs, Pypes mid mufflers, Che adj. LCA, hurst, 4.10's, 1 piece DS, spec stg 2 clutch. Accel coils 12.52@117.6mph so far with a 2.01 60 ft time(pre shaft, coils, clutch).
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Nope! I'd like to replace the block by this time next year. I really just want an excuse to take it apart! I'll probably run 15psi for awhile and see how that goes. This is not a track car so i'm not to concerned about that extra 60lbs of metal on the front end, but if there are other pitfalls with the cobra block then i'll spring for a new stock block.
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whipple HO SC,FRPP springs, Pypes mid mufflers, Che adj. LCA, hurst, 4.10's, 1 piece DS, spec stg 2 clutch. Accel coils 12.52@117.6mph so far with a 2.01 60 ft time(pre shaft, coils, clutch).
i'm using the iron block from MMR, mostly since it's stronger, although the aluminum blocks are plenty strong and something else will probably break first. it's 60#'s heavier, so not a ton. I figured i could save the $600 and cut 60#'s out elsewhere (swaybar delete, seats, or something). The block does not have provisions for knock sensors, which isn't a big deal because a lot of higher performance motors will set them off anyways. They are passive sensors, so all you do is just unplug them. It also requires an adaptor plate for the motor mounts, and one side only uses 3 of the 4 bolts. Again, not a big deal, works fine for me and MMR runs their huge HP cars the same way. All that to say, if I had to do it again, i may have gone with aluminum because i am taking it to the track more than i anticipated...
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2006 Roush
MMR 5.0L Stroker 950 shortblock and 800hp fuel system
Hellion turbo 14 PSI (555rwhp/593rwtq) Brenspeed Tuned
Spec Stage 3+
much more......
i'm using the iron block from MMR, mostly since it's stronger, although the aluminum blocks are plenty strong and something else will probably break first. it's 60#'s heavier, so not a ton. I figured i could save the $600 and cut 60#'s out elsewhere (swaybar delete, seats, or something). The block does not have provisions for knock sensors, which isn't a big deal because a lot of higher performance motors will set them off anyways. They are passive sensors, so all you do is just unplug them. It also requires an adaptor plate for the motor mounts, and one side only uses 3 of the 4 bolts. Again, not a big deal, works fine for me and MMR runs their huge HP cars the same way. All that to say, if I had to do it again, i may have gone with aluminum because i am taking it to the track more than i anticipated...
For a daily driver I would seriously consider keeping the knock sensors, they do tend to save ur engine. Thats the main reason why some engine builders ex. livernois have their stroker kits to 297/298 instead of 302 because with a 302 stroked you will loose the knock sensors. I prefer my engine to retard the timming when something is wrong/missfiring/small detonations etc etc.
Stock alum block is good for 900 - 1,000 hp anyway?
From my understanding I believe it is. The same reason I went with an new aluminum block for my 03 Cobra. The aluminum blocks on the 05+ Gt's are just as strong or stronger then the sought after Teksid blocks. All you need is a cobra crank, rods and pistons and you've got yourself a block capable of handing 900-1000rwhp. Tuning is a major part of that motor holding as well but the block itself is plenty strong.
Here's an excerpt from the September 2007 issue of MM&FF (page 46), the Horse's mouth article on FRPP's new line of aluminum 4.6 crate engines.
03-04 cobra block vs. stock block?
I'll probably run 15psi for awhile and see how that goes. This is not a track car so i'm not to concerned about that extra 60lbs of metal on the front end, but if there are other pitfalls with the cobra block then i'll spring for a new stock block.
