So I'm starting to research for internals for my 200 i6, and I'm wondering if I need a forged crankshaft for hopefully 200-250 hp and 10psi of boost (got alot of mixed answers online). Idk if my engine has been bored and forgot to check when swapping the cam, but I'll check when I get a 250 head put on it. And any other suggestions for this lmk because this is probably gonna take me 2 years of buying parts.
All Small Six Suggestions on internals
- Thread starter chiefbot1337
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This relates to all small sixes
You’ve caught my attention. I’m really happy with my NA engine but I’m thinking about boosting it in the near future too.
I was just having a chat in the YouTube comments with a guy who’s channel is Barra Stang. He has a Barra engine that will be going in fairly soon because he discovered that a stock bottom end on a 200 is plenty good up to 10 lbs of turbo but it will let go at about 15 lbs if you get overzealous. He got overzealous.
His 200 engine had a stock bottom, Clay smith 6474 camshaft, his head was ported and polished to some extent and he had opened up the log to fasten the 2V mounting plate directly to the log. I think he was using a Holley Sniper system but I may be mistaken. I don’t know what horsepower he was producing. The cool thing about this guys setup is that he modified an EBay header to sweep forward into his turbo rather than using the cast iron manifold and a u-pipe fitting.
I watched another YouTube on a NA 200 with the Classic Inlines head, sniper FI with a 4 barrel throttle body and sniper controlled ignition timing and a camshaft that give a broad power curve (the videographer’s description). His channel is under mechtrician1. He has it set up for a very smooth dyno result that reaches 150HP and 175 ft/lbs torque. The curve looks very streetable. If an engine like that were boosted, it would probably reach your goal. I don’t know what the HP/LB ratio is with these engines but 10 lbs must be worth 100hp on a sorted out engine running computerized fuel injection and spark control.
The Hermes Motorsports one that @bmbm40 suggested made 400HP and 500 ft/lbs torque with a log head and a turbo kit he pieced together before they got serious. He called that a very, very small turbo. He has a complete video describing everything he did. He put that video out about a month ago. It’s really worth checking out.
All that said, I’m not sure that you’re going to need an expensive bottom end. Just balanced with good bearings and rings. I would however use ARP or some other stud kit for the crank caps and the rods and the head as well. I’d get a cam that is going to work well with a turbo and of course, EFI and spark control.
Forget a steel crank, A not needed, B not available of the shelf. C Very expensive. For that level pf power all the stock stuff will hold up under street use. If you intended to belt the daylights out of it at the track, thats a different matter. 10psi might not get you 250bhp, 15 would probably do it. I run up to 15 on my X flow 200, I estimate Ive got about 250bhp, I run all stock stuff internally. However bear in mind the crossflow (Australia) head flows much better than any log head,. Better flow just means you get more power with the same manifold pressure. IMO a stockish cam works best with boost.
Ok, ya I'm not going to the track with it just a street driver with a little spunk. But should I still at least get forged pistons and rods? Also plan on going the supercharger route
Forged pistons, if you can get them cheaply, use them. They are expensive here in Australia so most people dont. Good quality cast pistons are OK, IMO the factory stuff is quite good. I am told some of the rods for your USA sixes are sintered metal, I wouldn't use these, however forged rods are available from a different, model use them, all the Falcon rods here are forged and we use them a lot. Like I said I'm supercharged and I use ALL stock internals without issues. With a street engine you only see full throttle for short periods of time, seconds, this means there is far less thermal loads on pistons. The cast nodular ford cranks are very good, only the really dedicated racers go to custom forged steel cranks, and they cost thousands.
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