Gary Lewis Posted April 24, 2019 Share Posted April 24, 2019 I am likely going to tear the front half off the motor and check the timing chain. Based on what Gary and others mentioned previously with the symptoms I provided, chain slip/gear slip could be a possibility. But what gets me is how off my firing order was. By this I mean my firing order was not standard, I cannot say what it was because I never wrote it down assuming it was the 351 standard, but after some research based on what you said apparently a 302 cam in a 351 with a firing order change (1-5-4-2-6-3-7-8) is not all that uncommon. I will test this tomorrow. EDIT: After some research I understand now that the 351 shares the same firing order as the 302 HO, and the 302 non HO has a different firing order. I will give this a shot tomorrow, if she runs I owe you a lot of beer. I wouldn't be in a big rush to pull the front of the engine off. I know the timing chains can get really...REALLY sloppy, but your issues only showed up after you were messing with the timing and firing order. There was another guy on here struggling with an ill running 351 for 2 months and he finally found out the darn thing had a 302 cam in it: http://forum.garysgaragemahal.com/Ferdinand-85-Bronco-351W-XLT-Phoenix-rebuild-project-tp14538p20678.html Get the engine back to where it was before you made the changes, and then go from there. The guys are right - don't pull the front apart until you figure out what is going on. As Cory said, it may have a cam that requires a different firing order. One way to find out the firing order is to mark the harmonic balancer every 90 degrees from the TDC mark. Then turn the engine to the first mark after TDC, pull the valve covers, and see which cylinder has both valves closed. Work through two revolutions and you should have the correct firing order. Link to comment Share on other sites More sharing options...
jstone4646 Posted April 24, 2019 Author Share Posted April 24, 2019 " I know timing is a big deal but as long as you are on TDC, and roll it back to 10BTDC, then ensure your dist. cap is facing cylinder 1" You want your distributor rotor at the number 1 cylinder at TDC on the compression stroke, not 10♀BTDC. Then time it with a light to 10♀ BTDC or per the specs. Hope you get it figured out quick. Grumpin and Rembrant, big shout out to both of you.....302 cam it was. I would have never figured that out. You guys are absolutely incredible sources of information, thank you guys, and everyone here so much for that! Link to comment Share on other sites More sharing options...
jstone4646 Posted April 24, 2019 Author Share Posted April 24, 2019 Grumpin and Rembrant, big shout out to both of you.....302 cam it was. I would have never figured that out. You guys are absolutely incredible sources of information, thank you guys, and everyone here so much for that! Now that it is running well, vacuum leaks plugged, ignition and starting issues sorted.....I think based on sound it is safe to say that the motor is not modified in any way. The side exit short pipes give it some added noise but does not sound like I have a performance cam or anything like that. Link to comment Share on other sites More sharing options...
Gary Lewis Posted April 24, 2019 Share Posted April 24, 2019 Grumpin and Rembrant, big shout out to both of you.....302 cam it was. I would have never figured that out. You guys are absolutely incredible sources of information, thank you guys, and everyone here so much for that! Glad you figured it out. But it was grumpin, not me. As for the sound and lack of modification, I would say it is pretty tame. But even a little bit more overlap or lift in a 302 cam will mellow out somewhat in the 351. Once you turn the dizzy to 10 BTDC check your vacuum - with no vacuum advance on it. If you are running 20+" of vacuum you have a nice, mild cam. Congrat's!!! Link to comment Share on other sites More sharing options...
grumpin Posted April 24, 2019 Share Posted April 24, 2019 Glad you figured it out. But it was grumpin, not me. As for the sound and lack of modification, I would say it is pretty tame. But even a little bit more overlap or lift in a 302 cam will mellow out somewhat in the 351. Once you turn the dizzy to 10 BTDC check your vacuum - with no vacuum advance on it. If you are running 20+" of vacuum you have a nice, mild cam. Congrat's!!! Happy dance time! Glad you got it! Now for more onion peels! This forum is great for help and knowledge! Edit: Ferdinand had this problem, so passing it on! Link to comment Share on other sites More sharing options...
jstone4646 Posted April 24, 2019 Author Share Posted April 24, 2019 Glad you figured it out. But it was grumpin, not me. As for the sound and lack of modification, I would say it is pretty tame. But even a little bit more overlap or lift in a 302 cam will mellow out somewhat in the 351. Once you turn the dizzy to 10 BTDC check your vacuum - with no vacuum advance on it. If you are running 20+" of vacuum you have a nice, mild cam. Congrat's!!! My vacuum is sitting right about 20 so that seems good. I did however find that when I put her under load by revving or dropping her into gear that she is still sputtering and popping (backfire). Then I saw that the rubber fuel line that connects to the metal line along the frame rail is zip tied in place.... so yea previous owner got lazy I guess. Anyways it was leaking fuel while the motor was running so I will just assume that is my cause of backfire under load....motor is too lean. I couldn't be happier though, time to really start getting this thing back together (and going through things to see what other Easter eggs the previous owner left me) Link to comment Share on other sites More sharing options...
grumpin Posted April 24, 2019 Share Posted April 24, 2019 My vacuum is sitting right about 20 so that seems good. I did however find that when I put her under load by revving or dropping her into gear that she is still sputtering and popping (backfire). Then I saw that the rubber fuel line that connects to the metal line along the frame rail is zip tied in place.... so yea previous owner got lazy I guess. Anyways it was leaking fuel while the motor was running so I will just assume that is my cause of backfire under load....motor is too lean. I couldn't be happier though, time to really start getting this thing back together (and going through things to see what other Easter eggs the previous owner left me) That is exactly what I had to do with my 1986 F250! Link to comment Share on other sites More sharing options...
Gary Lewis Posted April 24, 2019 Share Posted April 24, 2019 My vacuum is sitting right about 20 so that seems good. I did however find that when I put her under load by revving or dropping her into gear that she is still sputtering and popping (backfire). Then I saw that the rubber fuel line that connects to the metal line along the frame rail is zip tied in place.... so yea previous owner got lazy I guess. Anyways it was leaking fuel while the motor was running so I will just assume that is my cause of backfire under load....motor is too lean. I couldn't be happier though, time to really start getting this thing back together (and going through things to see what other Easter eggs the previous owner left me) As I am wont to say, these trucks are like onions. We peel and cry, but pretty soon we'll have a mess of onion rings! Link to comment Share on other sites More sharing options...
Recommended Posts