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#21
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Just a easy example of just ONE possibility with a solid flat 302/310 264/272 .675(w/1.8) 113 LSA 2 deg adv. 446 (4.21x4) 12.5 compression. 850 cfm carb. 607 ft lbs near 5500 rpm 741 hp at 7000 dropping to 735 at 7500. Tightening LSA brings power below 5200 up and kills power above 5500. LSA wider than 113 drops power below 5500 and starts to lose a couple hp at 7000-7500
A 1050 carb is good for another 20+ hp and 15 ft lbs at peaks. I didnt spend much time on this and can likely find better. CV1 with 1.71 ex valve 2.125 header. 621 ft lbs 765 hp 12.5 comp 5500-7500 rpm band seem close to what you are looking for??? Not bad for a flat tappet. A smaller 2 inch header knocks the curve down by about 20 numbers. Last edited by BruceWilkie; 02-02-2009 at 11:33 AM. |
#22
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my numbers are a bit more conservative, but yes..i could live with that..i think it will be interesting either way
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#23
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Interesting notes on exhaust size-I know I'll get hit with the "average HP comment, -but look at what the 600+ EM guys were using-few if any 2" , smaller ones mainly and alot of 600+ HP motors.
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Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
#24
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Skip, of interest here, when I was deciding cam profile for my Ford and looking at pump gas street type combos I was only losing 10-15 hp on top with the small street type tube modeling, the very low rpm side was up a lot. As it progressed into higher rpm racebands and 13.3:1 compression the large tube models really pick up and lose little below 3000.
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#25
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That wasnt with a lobe as radical as the xtq series. I punched in an appropriate sized xtq and there is possibly another 30 hp but lobe life will be less.
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#26
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When thinking of the reduced LSA, the thoughts of which lobe to move, in respect to IN or EX centerline, or the duration, ramp rate, of each lobe. Each change in cam timing can result in a different engine dynamic even with the same LSA. The exhaust's ability for the blowdown period is needed for the proper exhaust timing. The way the intake port works gives you an indication for the intake lobe. Varying the intake port's flow profile can allow you different valve timing aspects in regards to overlap. The speeds of air at each seat during overlap has a role in cam profile and overlap. So,
Would the exhaust lobe be moved to open the valve later and close it later, or just close it later? Would the intake open sooner or open and close sooner. I don't know the CV-1. And I don't look at a valve angle at it's ability to scavange because it is angled. I just look at those variables. Kaasse discussed his "reasons" on Speedtalk for a tight LSA. It doesn't work on everything. Depending on how the head "works", moving the lobes closer can have it's benefits where you can open the EX valve later (depends on how much force is still on the piston and if the port can blowdown fast enough), have it close later and open the IN a little sooner, (as long as the intake port does not promote reversion) and close the intake sooner to build more pressure before the spark. Try it. Especially if you have a cam around. |
#27
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Quote:
BTW the Engine masters engines are purpose built to get best average hp and tq numbers over an extremely wide 2500-6500 rpm band. Both Kaase entries are easily capable of 100 to 200 hp more with a cam change and reoptimization of the intake and exhaust. I know from talking with Kaases crew when I was getting my 528 parts gathered the "Street Boss" 429 is capable of 900 hp on pump gas. |
#28
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yes..i can always swap the heads off later to a real cv-1 built engine..this is for fun and education..
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#29
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Nothing wrong with fun and education. Any info is better than no info. The interpretation of that info is the fun part.
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#30
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Bruce how are you simulating a standard exhaust port compared to the convertible exhaust port?
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#31
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I havent! I'm still waiting on FlowData for the convertible exhaust! (there are a few people involved in various refinements of this head)No one has ordered it yet but it definately has advantage over the Pontiac droop, especially for a race header design, especially in a tube chassis car. I understand it is designed to use same bolt pattern as BBmopar but outboard tube spacing is slightly different.(NBD to section a mopar flange) The lack of the droop allows for better flow by not being confined to casting size and offers the opportunity to have a straighter shot out of the port.
Last edited by BruceWilkie; 02-03-2009 at 11:32 PM. |
#32
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It will be interesting to see what the Race Shop comes up with once they start working on it.
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#33
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a few other reputible shops are as well.
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