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Different sort of cam question #2549670
09/13/18 04:05 PM
09/13/18 04:05 PM
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Houston,Tx.
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Lee446 Offline OP
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I am going in another direction on a project. The 493rb that I have on the stand was originally built with equal parts street/strip in mind. It was originally around 10.5 comp with a set of Edelbrock performers with upgraded springs for a Porter custon solid 255/58 .580 (by memory) cam. My current 69 Satellite has a 528 hemi that is going to go into my wifes 70 Cuda/shaker hood. My thoughts are to cam down a bit for the 493 and turn it more towards a street/Tour type, since I am retired now and have more opportunity to do that kind of thing. I am swapping back to the 3.54 Dana from the 3.73, I acquired a GearVendors to put on my TF. I have a Dynamic 10" converter that flashed around 3700. Before I changed direction, I had the e-brocks cnc ported by Modern and they flow 325 on the intake according to the sheet, will that hurt efficiency due to lower port velocity? the heads were also milled to 79cc and with my combo will be right at 11-1, probably will go to a bit thicker head gasket to reduce that a little. I run a well set up six-pack which will remain. Before the port work, my 4120w/driver ran 11.40's through the full exhaust. Now, my question is, what would you look for in a performance cam, that would be fairly compatible, efficiency wise, with overdrive and cruising at approx 2500 rpm? Lets be clear, I realize it will never be a highly efficient modern engine, but how to optimize what I have as well as possible by cam selection and for example, going from a 108 to a 110 or 112 c/l.? dropping to 238-244@50 duration? Lower? Since I will be changing cams anyway, and I want to stick with a solid. I have a new M/P .528 solid in the box that has been sitting on my shelf for 15 years, I think it would be pretty mild, but AndyF has gotten some good results with it. Hoping to get close to mid 500 horse with good idle charectaristics(think being in Woodward Dream Cruise traffic!)
I have usually only cared about getting the most power out of everything so I will be interested in your opinions on this project.

Re: Different sort of cam question [Re: Lee446] #2549675
09/13/18 04:16 PM
09/13/18 04:16 PM
Joined: Oct 2003
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W. Kentucky
justinp61 Offline
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Call Dwayne.

Re: Different sort of cam question [Re: justinp61] #2549678
09/13/18 04:23 PM
09/13/18 04:23 PM
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Houston,Tx.
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Lee446 Offline OP
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Been dealing with Dwayne for years, and he will most likely supply the cam. I am looking for feedback from knowlegable people that may contribute ideas/experience. Hopefully Duane, AndyF, Streetwize or anyone else will chime in with suggestions.

Last edited by Lee446; 09/13/18 04:30 PM.
Re: Different sort of cam question [Re: Lee446] #2549730
09/13/18 07:22 PM
09/13/18 07:22 PM
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sweden
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carter Offline
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Just for comparison

512ci sitting in a bone stock E-body, 3860 with driver. This is my weekend cruiser that see a track once or twice a year. Beating on it for two summers since I built it, old school and simple.

4.25 x 4.375. B-block
TF 240 OOTB. 802-COO
10.4:1
Holley 850 DP (4781)
Holley SD intake with 1" open spacer
MP .528 with 1.6 rockers
6 Quarter "Hemi pan"
MP Dist 18°/36°
Carter mech fuel pump with 3/8" original fuel line
TTI 1 7/8 headers with full 3" exhaust

T/A 10" converter flash 4400 rpm

Rear 3.91 +Gear vendor = 3.05 and 9x28 slicks

Engine has plenty of vacuum for my factory PDB and sound "stock". Best ET so far is 7.19 x 95.61 MPH.
I hope for one more day at the track so I can do some more adjustments before I change camshaft.

IMO the MP .528 is a god street cam. I think you be satisfied with that cam.

Re: Different sort of cam question [Re: carter] #2549737
09/13/18 07:48 PM
09/13/18 07:48 PM
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ahy Offline
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I run a 243@.050 in a 496 and like it. Quite streetable. Your target for duration sounds about right. With cruising, OD and more low end torque I think you will want a tighter converter. Quite a bit tighter.

Re: Different sort of cam question [Re: ahy] #2549774
09/13/18 10:22 PM
09/13/18 10:22 PM
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Houston,Tx.
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Lee446 Offline OP
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A converter change is certainly not a problem, I have a reworked 10-3/4 hemi converter that was around 2800 behind a 500 horse 440. My flash stall on the current Dynamic is also behind an engine that developed 660 lb ft of torque, I wonder how much less stall it will have with the milder 493. I want enough stall to have no idle issues. I think I even have a stock Street hemi converter in the shop. If I went with the MP 528, the stock 10-3/4 would probably be enough. Carter, it sounds like it really works well for you and that is good to hear the voice of experience, I have that cam, so I may give it a try, but I am thinking maybe a touch bigger, My rockers are 1.5 RAS/Isky's. Your car is obviously an 11 second car, I could possibly live with a low 12 second car. But faster is always better!

Re: Different sort of cam question [Re: Lee446] #2549872
09/14/18 09:28 AM
09/14/18 09:28 AM
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Western NY
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maxi426 Offline
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I'm thinking your 11:1 compression might be a bit much with a smaller cam on pump gas.

Re: Different sort of cam question [Re: maxi426] #2549950
09/14/18 01:25 PM
09/14/18 01:25 PM
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BcudaChris Offline
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No tech from here, following with interest.

I had the compression thought as well. The right grind could probably lower the dynamic compression to work with the AL heads on pump gas. I imagine the idle would probably be suitably gearhead but with very nice manners from the 6Pak and the right converter.

Re: Different sort of cam question [Re: Lee446] #2549968
09/14/18 02:11 PM
09/14/18 02:11 PM
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sweden
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carter Offline
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For my engine above.

I had 165 PSI with MP .528 put in at 110
Now I have just istall a MP .557 in at 109 and cranking PSI is 155, maybe I would adv it 4 deg

Re: Different sort of cam question [Re: BcudaChris] #2549972
09/14/18 02:13 PM
09/14/18 02:13 PM
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Houston,Tx.
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Lee446 Offline OP
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The compression issue was a carryover from the previous direction of going back to bracket racing my street car. 93 octane is everywhere in the Houston area and I figured that between it and the 258@50 cam I was going to run, it would work out. now thats kind of a liability as cross-country, it can be hard to get even 90 some places. I need to do the calc to see how much comp I will lose by gouing to a .051 headgasket compaired to the old .039. It won't be much though.

Re: Different sort of cam question [Re: Lee446] #2550094
09/14/18 08:56 PM
09/14/18 08:56 PM
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Lee446 Offline OP
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Allright, after Dwayne and I had several conversations, we came to the conclusion "You can't get there from here". The compression could somewhat be alleviated by cam choice, but no guaranty that we could cover octane deficiecies in the boonies. Going to a thicker head-gasket loses what little quench my Wiseco flattops had and further aggravates the octane situation. We decided that the best way to build the engine that will do the job under the conditions specified, would be for me to buy a new set of Icon forged pistons with a 24cc dish which would be right at 10-1 and most importantly, provide quench. I will head out to the shop and start dissasembly of the new shortblock and replace the pistons and rings with the new ones. Gotta check piston weights as rebalancing could well be necessary. While I had not planned on throwing another 1K into the project, it is better to do it right than try to band-aid a marginal situation. Thanks to all who helped and a great Thanks! to Dwayne Porter of Porter Racing Heads who worked with me to help me understand the problems we faced! Onward through the fog!







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