ArdWrknTrk Posted August 6, 2021 Share Posted August 6, 2021 Well there may be a vacuum leak somewhere but there's bigger problems. Looks like the #5 exhaust lobe is wiped. Went to adjust/check them and when I took the valve cover off and went over to spin the engine, I noticed it barely moved and went and touched it and the pushrod isn't even touching the rocker. Unless it's just a mangled pushrod. 🤞 Are there less than 1,000 miles on that cam, or just on the plugs? What have you been using for oil, and how long did you use a break-in oil with high ZDDP? Sounds like you'll be tearing it down to change lifters and cam. Consider it an autopsy and take notice of everything as you remove it. Now I'm really surprised that it would be revving so high, if seven cylinders were constantly pumping against #5 with a closed exhaust valve. Link to comment Share on other sites More sharing options...
Weberman Posted August 6, 2021 Author Share Posted August 6, 2021 Unless it's just a mangled pushrod. 🤞 Are there less than 1,000 miles on that cam, or just on the plugs? What have you been using for oil, and how long did you use a break-in oil with high ZDDP? Sounds like you'll be tearing it down to change lifters and cam. Consider it an autopsy and take notice of everything as you remove it. Now I'm really surprised that it would be revving so high, if seven cylinders were constantly pumping against #5 with a closed exhaust valve. Took the pushrod and rocker off the one next to it and switched it just to see but still the same result. It barely pushes down on the spring while the other ones get pushed much farther. I have no idea how many miles this motor has on it, I bought it with the cam installed. That being said, I've been using diesel oil as I've heard its the best off the shelf for flat tappets. Is it worth to tear down for lifters and cam? I figured it would be a full on rebuild since that metal had to go somewhere. I figured the bearings are already on there way even if I flushed and did many quick oil changes. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 6, 2021 Share Posted August 6, 2021 Took the pushrod and rocker off the one next to it and switched it just to see but still the same result. It barely pushes down on the spring while the other ones get pushed much farther. I have no idea how many miles this motor has on it, I bought it with the cam installed. That being said, I've been using diesel oil as I've heard its the best off the shelf for flat tappets. Is it worth to tear down for lifters and cam? I figured it would be a full on rebuild since that metal had to go somewhere. I figured the bearings are already on there way even if I flushed and did many quick oil changes. Any metal should end up in the oil filter. I would want to do a leakdown, but if the rings and valves are tight (something under 15-20%) there's a good bit of life left in it. Besides a cam and lifter kit is a LOT less than an engine and it can be done in the truck. If the cam journals are worn too bad then maybe you have to dig deeper but I wouldn't write the engine off just because of a bad lobe Link to comment Share on other sites More sharing options...
Weberman Posted August 6, 2021 Author Share Posted August 6, 2021 Any metal should end up in the oil filter. I would want to do a leakdown, but if the rings and valves are tight (something under 15-20%) there's a good bit of life left in it. Besides a cam and lifter kit is a LOT less than an engine and it can be done in the truck. If the cam journals are worn too bad then maybe you have to dig deeper but I wouldn't write the engine off just because of a bad lobe Idk, but maybe its the luck I've had with this journey/engine but hopes aren't too high haha. I'll try to find a leak down tester and see what it is. Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 6, 2021 Share Posted August 6, 2021 Idk, but maybe its the luck I've had with this journey/engine but hopes aren't too high haha. I'll try to find a leak down tester and see what it is. Harbor Freight sells a decent leak-down tester. Link to comment Share on other sites More sharing options...
Weberman Posted August 18, 2021 Author Share Posted August 18, 2021 Harbor Freight sells a decent leak-down tester. Still need to do a leak down and see. But a 351w roller swap has been tempting me if I'm going to be honest. Just easier to get the power/torque out of a 351, that stroke helps a lot. Is there anyway to tell what splines a 9inch is? I was thinking about swapping chunks out but didn't want to tear each axle apart and have them be different splines, plus just swapping the rear sounds easier than taking the axles and chunk out. Link to comment Share on other sites More sharing options...
Weberman Posted August 22, 2021 Author Share Posted August 22, 2021 Still need to do a leak down and see. But a 351w roller swap has been tempting me if I'm going to be honest. Just easier to get the power/torque out of a 351, that stroke helps a lot. Is there anyway to tell what splines a 9inch is? I was thinking about swapping chunks out but didn't want to tear each axle apart and have them be different splines, plus just swapping the rear sounds easier than taking the axles and chunk out. Didn't want to post anything til it was on and fully done. But finally got a good call back on a bumper that could be shipped. It looked great too, I'll clean it up even more when it's bolted down more. Currently just have 2 bolts on one side and 1 on the other til I get some new bolts for it. Link to comment Share on other sites More sharing options...
grumpin Posted August 22, 2021 Share Posted August 22, 2021 Didn't want to post anything til it was on and fully done. But finally got a good call back on a bumper that could be shipped. It looked great too, I'll clean it up even more when it's bolted down more. Currently just have 2 bolts on one side and 1 on the other til I get some new bolts for it. Looks good! Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 23, 2021 Share Posted August 23, 2021 Didn't want to post anything til it was on and fully done. But finally got a good call back on a bumper that could be shipped. It looked great too, I'll clean it up even more when it's bolted down more. Currently just have 2 bolts on one side and 1 on the other til I get some new bolts for it. That's one of the fancy bumpers. Love it! Link to comment Share on other sites More sharing options...
Weberman Posted August 23, 2021 Author Share Posted August 23, 2021 That's one of the fancy bumpers. Love it! Yeah, thats part of the reason why I think it was so hard to get one. Needing the Bronco specific brackets since mine were some thrown together ones that the previous owner made and wanting that bumper. A tailgate to look better and redo the window motor so that will be good and I think it'll be good to rock for awhile besides the engine. Link to comment Share on other sites More sharing options...
Recommended Posts