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#1
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This winter I plan to rebuild the 360 in my '79 300 with 118K on her. This car is my daily driver and rarely sees the track. This is going to be a budget build-up designed to perform well on the street. I have most of the guts planned out but have a few questions.
1. I had thought of going to MSD-5 ignition. I have read all the hype but does it realy make that big a difference over stock points on the street? 2. What would raising my CR from 8.2 to 9.5 buy me? I use the cheapest mid-grade fuel I can find. 3. Which is better more lift or duration? I have heard both big-lift/short-duration and small-lift/long-duration work best in Mopars. The car has to pass MD emitions! 4. I am thinking of replacing the TQ with a Holley. The TQ rebuild kit cost keep going up and the quality keeps going down. Holley makes a two piece carb #4010 600cfm Vac. It has all the latest Holley technology with out all the cost. Anyone know of any problems with them? Thank you for your help, in advance. ------------------ Im fluent in several forms of Nerd, including Geek |
#2
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Quote:
2. It won't do much of anything. if you want to use crappy fuel, then keep it under 9:1. 3. One way to look at it is: duration affects the rpm range of the engine, lift affects how much airflow you'll get in that rpm range. That's not a complete answer, but you're asking an age-old, complex question, and it's the best I can do. 4. Do not, under any circumstances, use a 4010 or 4011 Holley. They are the biggest piece of junk Holley ever made----Latest technology?? Those carbs are re-hash of a 1960's Motorcraft carb, I have recently found out. Again, don't do it, no matter how good a price you can get on it. What would I do? Well I just did a 360 that'd probably work pretty well for what you're trying to do. -.030 over -8.8:1 (actual, measured compression---not just what the piston manufacturer advertised---which was of course was not even close to reality) -MP 260/272 cam -Aerohead smog heads with 2.02/1.6's, mildly ported (by me, not aerohead) -performer manifold -600 Holley,(list 1850) -el cheapo Summit 1 5/8 headers There are a few other minor tweaks, but this is the basic combo anyway. In a Diplomat with 3.21 gears, a 727 and stock converter, it's a torque monster and still gets about 15-16mpg on 93 octane. It will run just fine on 87 or 89 octane too, but will only get about 12 to 13mpg on the cheaper gas. Though it isn't a worry around here, emissions shouldn't be a problem as long as the car can be smogged as one originally built with a HP 4 bbl engine. I suggest you check your local laws, to be sure though. |
#3
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Stay away frpm the 4010, they might say it has "new" technology but it is actually old tech, derived from the old Motorcrap carbs. I ran one (actually a 4011) on my 318 nad it was a pile o' crap. I have heard of these carbs being known as "boomarang" carbs as they seem to always return to the factory after being shipped. If you are going to go with a Holley then the tried and true 4050/4060 series. With the 360 you could probably go with a 750 cfm carb. As for cam choices, i am going with a longer duration, low lift cam (225* dur @.050, .453 lift) cam. I have heard that I should get a bit steeper gears first though. I don't have any ideas on the ignition, I used the MP ignition package. As for the compression ration, I replaced my low compression heads with closed chamber #302's and the torque is wonderful, my car now acce;erates as hard as my father-in-laws 360 powered Prospector. I would hazard to guess about 15-20 hp for a point of compresion, but don't quote me on that. cruzerjd
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#4
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Stay away from the 4010 carb. Had one. Sittin on the shelf. (Actually, I thought Holley quit making them.)
As far as lift/duration, I can't think of a good reason not to run as much lift as possible for a given duration. Duration tends to set the general rpm range. So pick the rpm range you want (I recommend using the duration at .050") and buy a cam with the most lift for that duration. Hughes and Ultradyne are two good companies. I think Ultradyne grinds Hughes' camshafts anyway. ------------------ 68 Cuda, twisties style http://members.xoom.com/magnumcuda/sprfish.htm 96 Club Cab 4x4, Cummins 5spd |
#5
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since you have to pass the sniffer test and I don't know the limits of your state. I would not go beyond the stock 4bbl cam. MoPar still makes this cam. It's the same as the old 340's had. PLESE DOUBLE CHECK ME ON THAT. Because the cam will fail your car in a heartbeat if it's to large.
Holley did stop making the 4010/4011's. I put on a carter 625 emisions carb without a problem. The MSD 6 box is better than the 5-box. The raising of the compresion will mean the use of a higher octane. NO CHEAP STUFF. |
#6
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No Holley 4010 or 11....crap....no holleys for emissions period.The carter or Edelbrock are the way to go.For monster torque in a 360 use P4452759.Stick to 9:1 comp in this heavy of a vehicle with iron heads.1 last thing,this should be a 360hp in 79 300!!! rated at 260hp,if so the stock cam is identical to the 340 resto cam(429/444 268/276)if so re use if if poss,if not buy a new one P4452782 because it will meet emissions and out power the others mentioned......PRO....
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#7
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My 360 setup:
Hughes HE0914AL cam, shoot for 9.0:1 actual compression ratio (I am running 9.5:1 with KB232 quench dome pistons at 6,000 ft altitude.) I have the AeroHead 2.02/1.60" 360 heads that I ported, but I would recommend the mildly ported 360 heads from Hughes with the 1.96"/1.65" valves. I have a Performer intake with EGR and Thermoquad carb so all the emissions junk will hook up. The ignition id the Mopar electronic conversion kit with stock style chrome "energy core" coil fron Jacobs, and Jacobs spark plug wires. The exhaust is all Dynomax, Headers, dual 2.5" mufflers any dual 2.5" 3-way converters with airtube. Airtube(s) connected to air pump. |
#8
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Thank you all for the info on the Holley 4010. Yes, it is the 300HP but it is only rated at 195HP with the ECU. The big smog advantage I have is the dual cats and no air pump stock. I am looking to only bump up the cam a notch or two.
I figure that smog legality would be on the minds of the cam manufactures when they come out with new grinds. My current choices are Comp Cams Xtreme Energy #XE268H PN 20-223-3 or Mopar P4452761. Both offer more lift but keep the duration short and close to stock. A guy at Hensley Racing told me that large duration is bad for emitions. Something about vacuum loss, cylinder pressure, and scavenging. Anyhow he suggested I get the P4452761 and bump the CR up to 9.0. Does any one know the specs on "596" casting heads? That is what is on the engine. I had though of getting better heads but the cost stopped me. I might try to search for the "308" high swirl heads, but from what I have been told they are next to impossible to find. ------------------ Im fluent in several forms of Nerd, including Geek |
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