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Discussion Starter · #1 ·
hey guys, im working with a factory block 351c with 2v heads that are mildly worked over. it has a comp cams magnum 282 series cam. advertised specs are as follows .570"/.570" lift 282*/282* lsa 106*. its just above 10.5:1 comp, weiand x-celerator single plane intake (1500-7000 rpm), mighty demon 750, msd digital 6 ignition with blaster ss coil, locked out msd pro billet distributor with msd crank trigger, full aeromotive fuel system (a1000 pump). i have autolite ar134 plugs gapped at .36 and if i recall i have the total advance set at 36*

now is there anything that i should reconsider or change (timing, plugs/plug gap) i have a feeling the carb may be too big but its what i had. i dont think im gonna buy a new one because sometime in the future i plan on using one of them self learning efi kits and would rather apply the funds to that. so i gotta work with what ive got for now. let me know what you guys think. thank you
 

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Make sure to set fuel pressure to 7-7.5 psi. Total timing of 36 is a good starting point for the motor. You could go + or - depending on car weight and trans. Just do a baseline setup on the carb for initial start up and once the cam is broken in, you can tune to suit. Carb isn't too big IMO but it all depends on your use (street or strip) either way, you should be able to set it up nicely. I had a similar setup on my 351 C years back with a Holley 750 DP (street/strip use) and was very street able.


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Open those plug gaps. MSD recommends .050" to .060" to start small, and then open that gap until you get best performance. Big gaps. The widest gap that gives a reliable spark will give you best performance. I usually open the gaps .005 at a time, make a run, and when it begins to miss I close it .005 (race) or .010 (street) and it's done.

David
 

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Discussion Starter · #4 ·
holy smokes!!! and i mean smoke. or fumes. that thing is still running super rich. i backed down on the jetting from the factory size by 5 sizes. since i have the crank trigger checking the timing was relatively easy. turns out the timing was at 28/29. ???? got me? anyways i pulled the distributor set the timing at 36 and put the distributor back in. at least this way im closer to where i need to be so when making fine adjustments on the sensor bracket i dont run out of room.
now the ar134 plug is supposed to be a step up from middle heat range.( i picked up a set of ar135 plugs which are the hottest plug they offer.)
now that the timing was reset and the carb was returned to base settings (except for the jetting.) it started a bit more strong and ran stronger but man, i had to run the mixture screws just about all the way in to get the a/f readings even close. driver side was reading between 11.5- low 12. and the passenger side was reading mid 13.- mid to high 14. (im using a fast dual bank a/f reader)
anyways. i had to shut it down. i pulled the plugs and they were full of carbon again. totally blacked out.
im gonna try the ar135's and open the gap a bit and see where that gets me. other than that. do you guys have any advice or thoughts??
 

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holy smokes!!! and i mean smoke. or fumes. that thing is still running super rich. i backed down on the jetting from the factory size by 5 sizes. since i have the crank trigger checking the timing was relatively easy. turns out the timing was at 28/29. ???? got me? anyways i pulled the distributor set the timing at 36 and put the distributor back in. at least this way im closer to where i need to be so when making fine adjustments on the sensor bracket i dont run out of room.
now the ar134 plug is supposed to be a step up from middle heat range.( i picked up a set of ar135 plugs which are the hottest plug they offer.)
now that the timing was reset and the carb was returned to base settings (except for the jetting.) it started a bit more strong and ran stronger but man, i had to run the mixture screws just about all the way in to get the a/f readings even close. driver side was reading between 11.5- low 12. and the passenger side was reading mid 13.- mid to high 14. (im using a fast dual bank a/f reader)
anyways. i had to shut it down. i pulled the plugs and they were full of carbon again. totally blacked out.
im gonna try the ar135's and open the gap a bit and see where that gets me. other than that. do you guys have any advice or thoughts??
crank trigger????????? there is no reason for that type of system on such a mild engine. unlock the dist. and get a correct timing curve.

you check the fuel bowl level ? fuel pressure? might have a blown power valve
 

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Discussion Starter · #6 ·
crank trigger????????? there is no reason for that type of system on such a mild engine. unlock the dist. and get a correct timing curve.

you check the fuel bowl level ? fuel pressure? might have a blown power valve
yeah a crank trigger. i know its overkill. but at the time i bought it i was under a different understanding of it. i did go back and check all adjustments and settings as well as phasing the rotor.
i tried a new 6.5 power valve but it yeilded the same results. but this time i tried running in both front mixture screws till they bottomed out. it kept running. so then i took note of my vacum and it was below the 6.5 rating of the power valve. it was 5-5.5. so with that being said i took that one out and tried a 3.5 . that seemed to be the ticket. but i wonder, 5/5.5 in vacum. does that sound right for a cam that size (comp cams magnum 282 series flat tappet 282* .570") my averaged a/f reading was 13.6-13.8.
one thing i didnt like was the overall behavior of the idle. for starters the passenger side seemed to idle more rapid than the driver. the driver side had a more traditional lope to it. i could tell thiis because it was blatantly clear by just listening to each exhaust pipe. the other thing was the passenger side also had a higher temp to it(used one of them hand held temp guns pointed at the primary tubes on the headers), as well as a valve clatter.
so its obvious i still have some bugs to work out but i am getting closer. feel free to offer any other input if any. thanks
 

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your claiming 10.5 comp ratio . know that number can be had. how did you get 10.5 ratio? did you degree the cam?

try tuning with dist. back to mech. advance . always go back to crank trigger. Note -to much advance can/will drop vacuum at to rpm.
 

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You may find the Autolite AR135 racing plug with the retracted tip will load up with alot of idling and low speed driving. The MSD may help with this though. I tried AR135s on the street in my Cleveland and had problems with them loading up. I was not running an MSD ignition. I am running Autolite 23 plugs now with no problem. You will want to run 15 or so initial timing with that cam.
 

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Discussion Starter · #9 · (Edited)
ok. today was a productive day. after I figured out the carb needed the lower rated power valve I was getting somewhere. the truck still idled like crisp and had a nasty valve noise coming from the passenger side of the motor. So off came the valve covers and I went through each one. cylinder#2 exhaust was the culprit. the rocker had no adjustment to it. when there was no tension on it the rocker flopped around. I was bringing to think I had a bad cam before I found the loose rocker. I got a peek at the lifter and saw it set just as low as some of the others. So I wasn't worried about a wiped lobe any more. so after doing all the valves and double checking them I put it back together and fired it up. what a big difference. now it idles like I expected. for it sitting still the air fuel mixture reading is pretty good. I'm not gonna be able to tell how everything really is till I get an alignment and paperwork on the thing. here's a little phone footage of it running. if you look for the other video of it running you'll hear the issues I was having.

https://www.youtube.com/watch?v=3-irh51n1RY&feature=youtube_gdata_player

btw. the red cap I was only using to phase the rotor. it has a nice black msd cap on there now, heh heh.
 

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I understand that. I am waiting for spring to finally get here so I can get my Mustang out to test the freshly rebuilt trans. It looks like we will have some more snow tomorrow.
 

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Discussion Starter · #13 ·
I understand that. I am waiting for spring to finally get here so I can get my Mustang out to test the freshly rebuilt trans. It looks like we will have some more snow tomorrow.
Yeah. I see that. you'll probably get more snow than I will.I usually get the joke end of the storms. the most movement my project has seen is on and off the Jack stands. I'm getting very anxious to get it to roll under its own power and reek some havoc upon the poor unsuspecting citizens of my town. haha!!
 
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