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Discussion Starter #1
I’ve got a couple questions while the machine shop works on my short block. At what point should a full size crank key be run vs the stock one? Also looking to see what size injectors to run on my build. I’m thinking 30s or 36s but I see a few 39s around for cheap just concerned it’s too big and the spray pattern not ideal for a 2v? It’s a na street build. No plans for boost anytime soon.

My build:
38cc tfs heads
CMS stage 3 na cams for tf heads
Ported svo intake
Mac long tubes
Lightning maf
Compression will be at 11.6-1 on 93.

TIA
 

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King Trashmouth
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21,891 Posts
I haven't seen anyone go to a bigger crank key on these engines. Hell, the stock one puts up with abuse from some pretty big blowers. And the guys that really beat the crap out of them just double key it. But those are big displacement blowers; you won't need it.

Going a little bit larger on injectors isn't going to hurt. You have to go pretty big before you start getting driveavility issues.

There's another note about the 39lb/hr Cobra injectors though; they use a split spray pattern due to it being a 4V design. This isn't ideal for a 2V. People have run them, but if you have the choice, a single spray pattern injector is better for your application.
 

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Discussion Starter #3
Thanks!
I thought I’d be ok with the half moon shape stock key but thought since it was at shop they could cut a full size key easily. My tfs crank gears are pinned as well. Are 30s too small? I’ve seen a similar build make 360rwhp. I hope to make around that.
 

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King Trashmouth
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21,891 Posts
Is that on the balancer or cam gears? The stock ones have them cast into the crank or cam gears. Some aftermarket ones like Cloyes gears have a keyway cut in the gears as well, necessitating the use of the provided key blanks, but those are rectangular rather than half moon. Even those are stock size and more than strong enough to hold NA power and then some.

Running it through a basic injector calculator, even keeping the duty cycle as low as 85%, Ford 39psi base pressure, 32 lb/hr should be sufficient for 360rwhp. 30lb/hr would be at 90% which is manageable, but it's always nice to have room to grow.
 
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