Stage 3 MTI heads and a 346 shortblock?
Re: Stage 3 MTI heads and a 346 shortblock? personally, I think so. Nothing wrong with stage 2.
You would probably be giving up torque and drivability midrange and below so that you could get a couple more HP at 6700 rpm.
chris
You would probably be giving up torque and drivability midrange and below so that you could get a couple more HP at 6700 rpm.
chris
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Re: Stage 3 MTI heads and a 346 shortblock? I won't be spinning the motor more than 6K rpm so I don't think I'd be getting any advantage over Stage 2's. On the other hand, MTI Stage 3's have some awesome flow numbers 
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From: Your Reality Check Bounced...
Re: Stage 3 MTI heads and a 346 shortblock? go stage 2 +...get the bigger valves but don't let them touch the combustion chamber or you'll loose a lot of low end power and gain hardly anything up top....stage 3's are for all bores and big cube motors.
Re: Stage 3 MTI heads and a 346 shortblock?
. . . You would probably be giving up torque and drivability midrange and below so that you could get a couple more HP at 6700 rpm.
chris
chris
Stock idle. No idle or part-throttle driving issues whatsoever
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Re: Stage 3 MTI heads and a 346 shortblock? I am VERY happy with my stage 3 heads (2.08"/1.60" valves with a massive port job) on my stock 346. I would like to some day do a big bore motor to take "better" advantage of the heads but till them I'm going to install a larger cam (mid/high 230s duration.....G5X would be nice) to crank some more hp out of this thing.
Since I can't scan my dyno sheet, I listed the specs below. I dynoed the car on 91 octane in 100+ degree AZ heat with the TR224 (224/224 .563/.563 112 LSA) cam I have in the car now. I noticed the torque peaked a little late (5000RPM vs. typical 4800RPM) which has got to be a result of the valves, yet really, I'm surprised to see the torque curve as flat as it is. I expected (because of what everyone told me "would" happen) it to be really poor low and mid RPM, and then "possibly" brake even up over 6000RPM. To give you an idea of the graph, the hp/torque goes:
121hp / 290tq @ 2200RPM
142hp / 309tq @ 2400RPM
161hp / 325tq @ 2600RPM
182hp / 341tq @ 2800RPM
200hp / 348tq @ 3000RPM
218hp / 357tq @ 3200RPM
231hp / 356tq @ 3400RPM
285hp / 357tq @ 3600RPM
262hp / 361tq @ 3800RPM
280hp / 367tq @ 4000RPM
298hp / 372tq @ 4200RPM
312hp / 372tq @ 4400RPM
329hp / 376tq @ 4600RPM
348hp / 381tq @ 4800RPM
366hp / 385tq @ 5000RPM
376hp / 380tq @ 5200RPM
385hp / 375tq @ 5400RPM
392hp / 367tq @ 5600RPM
398hp / 360tq @ 5800RPM
400hp / 349tq @ 6000RPM
398hp / 337tq @ 6200RPM
394hp / 323tq @ 6400RPM
385hp / 336tq @ 6600RPM
371hp / 287tq @ 6800RPM
Since I can't scan my dyno sheet, I listed the specs below. I dynoed the car on 91 octane in 100+ degree AZ heat with the TR224 (224/224 .563/.563 112 LSA) cam I have in the car now. I noticed the torque peaked a little late (5000RPM vs. typical 4800RPM) which has got to be a result of the valves, yet really, I'm surprised to see the torque curve as flat as it is. I expected (because of what everyone told me "would" happen) it to be really poor low and mid RPM, and then "possibly" brake even up over 6000RPM. To give you an idea of the graph, the hp/torque goes:
121hp / 290tq @ 2200RPM
142hp / 309tq @ 2400RPM
161hp / 325tq @ 2600RPM
182hp / 341tq @ 2800RPM
200hp / 348tq @ 3000RPM
218hp / 357tq @ 3200RPM
231hp / 356tq @ 3400RPM
285hp / 357tq @ 3600RPM
262hp / 361tq @ 3800RPM
280hp / 367tq @ 4000RPM
298hp / 372tq @ 4200RPM
312hp / 372tq @ 4400RPM
329hp / 376tq @ 4600RPM
348hp / 381tq @ 4800RPM
366hp / 385tq @ 5000RPM
376hp / 380tq @ 5200RPM
385hp / 375tq @ 5400RPM
392hp / 367tq @ 5600RPM
398hp / 360tq @ 5800RPM
400hp / 349tq @ 6000RPM
398hp / 337tq @ 6200RPM
394hp / 323tq @ 6400RPM
385hp / 336tq @ 6600RPM
371hp / 287tq @ 6800RPM
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Re: Stage 3 MTI heads and a 346 shortblock? I punched in your numbers on Excel just to see what the curves would look like, and I thought they looked a little on the peaky side, when compared to a lot of the graphs I see on here. Then again, it could be because your pull started at such a low RPM...
What's the story with the HP spike at 3600RPM? Typo?
What's the story with the HP spike at 3600RPM? Typo?
Re: Stage 3 MTI heads and a 346 shortblock? Ouch. Dang. I can see what everyone's talkin' about here. If you have full bolt-ons and tuning then you are losing low-end tq from those heads.
I make over 350 rwtq from as low as 2500 rpm's with a peak over 400 rwtq. My pulls on the dyno are to 6800 rpm's as well. I never drop below 305 rwtq . . . even to my rev limiter of 6900 rpm's. It defnitely looks like your tq is peaky. My curve is reeeeally flat. I guess this is an FYI for anyone who reads this.
I guess a fat nasty cam would work better than our little Thunder cams . . . funny . . . When I bought my cam it wasn't so "little" compared to the choices back then
I make over 350 rwtq from as low as 2500 rpm's with a peak over 400 rwtq. My pulls on the dyno are to 6800 rpm's as well. I never drop below 305 rwtq . . . even to my rev limiter of 6900 rpm's. It defnitely looks like your tq is peaky. My curve is reeeeally flat. I guess this is an FYI for anyone who reads this.
I guess a fat nasty cam would work better than our little Thunder cams . . . funny . . . When I bought my cam it wasn't so "little" compared to the choices back then
