I'm pretty new when it comes to this stuff. Most of the stuff that I have learned has been online forums like this or through email. I'm really kinda stuck right now and don't know what I should do next to figure out whats wrong with this thing. I appreciate any help/suggestions. Thanks. 'History' of the engine The 292 was rebuilt by the previous owner and never installed. When I got it, I swapped out the cam for something bigger (264-H 264 duration 214 @ .050" .498" lift 110 lobe center ). I installed the rebuilt engine using most of the stuff that was on the engine that I pulled out (with the exception of new plugs, wires, distributor cap). I had some problems adjusting the valve lash and setting the timing. I did not check that the mark on the harmonic balancer was correct when I had the head off. A neighbor helped me with the timing (oops - we ended up re-marking the balancer). Even after we thought that the timing was correct, the truck still was not running well. I changed the inline fuel filter, but not much changed. I noticed that there was also a filter inside of the carb. It was really dirty, so I pulled that out the the truck ran better, good enough for me to drive it a few miles (about 4) when we moved. The truck then sat for about a year without me really touching it. A couple of weeks ago I installed a new distributor cap and rotor (hei). This week I tried cleaning the carb, adding techron and fresh gas, but it didn't really change much. When I drive it, it seems to pull pretty good when you start off, then all of a sudden it kinda 'peaks' and doesn't want to go any faster and doesn't pull anymore. The old engine that was in it seemed to have more power. It also backfires every once in a while, usually right after shifting. I wonder what the next step should be in troubleshooting the problems with the truck. I can think of a few possibilies: Q1. Should I install a different carb? Q2. Should I try to adjust the valve lash, this time with the truck running. Q3. Should I pull the head, double check the mark on the harmonic balancer, the re-adjust the valve lash and re-time the truck? Installing a different carb: You will see from the pictures below, that the carb that came with the truck looks pretty beat up. I have another carb that is similar to the one in the truck. If it is a good idea for me to try installing the 'new' carb, I have a few questions about the install. I also have a few questions about the carbs in general. Carbs Front - Questions: Q4. #1-(answered below - thanks cruisinkruty) Q5. #2-This is where I removed the filter from. You can see the clear inline filter in the foreground. Carbs P***enger Side Questions: Q6. #1-(answered below - thanks cruisinkruty) Q7. #2-(answered below - thanks cruisinkruty) Q8. #3-(answered below - thanks cruisinkruty) Q9. #4-(answered below - thanks cruisinkruty) Q10. #5-(answered below - thanks cruisinkruty) Q11. #6-(answered below - thanks cruisinkruty) Q12. #7-If I were to attach #4 to this carb, would the end of the hose go here? Carbs Back Question: Q13. #1-(answered below - thanks cruisinkruty) Carbs Driver Side Questions: Q14. #1-Should I lengthen this hose? Adjusting the valve lash with the truck running Well this looks like it could get really messy, but if it help, it will be worth it. Some questions: Q15. The truck seems to be idling kinda fast, so should I try to slow it down some before doing this? Q16..Should I clean up the oil that is on top of the rockers before starting the engine? Q17. I've read about the process before, is this correct? Loosen one rocker nut at a time. Loosen until it starts to rattle, then tighten 1/4 - 1/2 of a turn. (answered below - thanks budd) Other Possibilities? Could the following things be causing problems? Q18. The 1 BBL carb isn't big enough for the overbored engine(.040 over I believe) with the bigger cam. Q19. The exhaust is manifold is from a 194. The 292 manifold was cracked and in really bad shape. Q20. When I try to start the truck when it's been sitting for a day or two, it doesn't start or has a hard time starting until I dump some gas into the carb. Is there some sort of overflow for the gas to escape through, or is this not normal (see pic)?
to set your valves with the engine running, yes you loosen one rocker nut at a time, when you can hear it rattleing good you tighten it just till there is no more rattle, thats zero, now if you have aftermarket lifters then they should be set by the instructions that would of came with them, stock lifters can be set 1 full turn in after reaching zero lash, some aftermarket lifts call for only 1/4 turn, another trick with setting lifters with your engine running is to take an old valve cover and cut a slot out of the top just wide enough to get your socket and extension in, first glue a gasket on, no oil mess then.
Make sure that the mechanical advance is not stuck. Just grab the rotor and twist, if it don't move (other than the slack in the gear drive) then that is your problem, symptons are ideal for this scenario, 9 out of ten computer simulations give this solution.
Thanks for the help everyone. budd - thanks for the tips on adjusting valve lash. the engine was rebuilt and never run before I started it up. I was told by the cam manufacturer (shneider racing cams) that the stock lifters were fine, since they were new. Unclee - This is how much I can turn it until I feel it 'lifting up.' Q20. Should I be able to turn it more than this? Q21. Visually, how do you tell the difference between a mechanical advance and a vacuum advance? When I took the distributor cap off, I noticed this. The cap and rotor probably have less than 10 miles on them. Q22. Why is the rotor hitting the inside of the cap?
the problem with the carb is most likely the accelerator pump (power plunger) inside the carb.i had the same problem on my 292 in my 68 chevy truck daily driver. either the diaphram pulles off the metal center and jammed or the metal arm that accuates it bent away from the metal center and jammed. take the top of the carb off and look inside. you can still score a rebuild kit for these carbs for about 10 bucks from auto zone. i have a clifford reaserch intake with a newer holley 2 barrel for sale and a clean exhaust manifold from a 71 250 engine
Q#1 That used to go to the carbon cannister for Evap emission control..Q#6That is an electric idle stop solenoid,Q#7&8Those vac ports are timed vac ports for use in vac advance,egr and other emission related systems.Q#9 that is a choke pull off"late design"Q#10 that rod connects to the divorced choke coil mounted on your exhaust manifold.Q#11 this is the early design choke pull of .Q#12 that is for the carbon cannister also for the evap emission system.Q#13 that is not a vac advance it is a choke pull off! Your vac advance cannister is on the distributor and should have timed ported vacuum hooked to it NOT MANIFOLD VACUUM! Also I suggest using the original carb as the jet and metering rod are sized for the 292 as the other carb looks to be off a 250 and should have a smaller mainjet and metering rod.
Was the head set up for that much valve lift? .500 lift seems to be a bit much for stock old springs.
greyone - the cam came with new springs executioner - I will pull the top of the carb off this weekend and post some pics of what I find. I will send you a PM later regarding the stuff you have. cruisinkruty - thanks for the explanations. I had a bit of a 'brain fade' on the vacuum advance question. I was really tired yesterday. I have to run now, but I will try to give you a better idea of what I'm doing with the engine - it's not staying in my truck...
The 292 is currently installed in a 1970 c-10 that I bought two years ago. The truck has basically just sat since I bought it and I have decided to sell it b/c I bought another truck (66 c-10). I plan on pulling the 292 out of the truck once it is running well. I would like to sell the truck without an engine, but if that's not possible, I have a 250 sitting in my garage... I would like to put the 292 in my nova (which currently has a 194 in it). I'm told that it will be a tight fit clearance wise, but it has been done. I have an offy intake, a 390cfm holley and a set of stovebolt cast iron headers for it. I've been talking with a few guys over at inliners.org regarding the install. I was thinking about installing the offy and 390 on the 292 while it is on the truck, but that seems like a lot of work for a temporary setup (figuring out linkage). executioner - you have a pm cruisinkruty - the vacuum advance's hose attaches to the same line coming out of the bottom of the carb as the choke pull off (below the connection for the carbon cannister). Where should it be attached to have timed ported vacuum?
I pulled the carb apart and took some pics. Here's what I'm working with: inside_carb1.jpg inside_carb2.jpg inside_carb3.jpg inside_carb4.jpg I'm not sure what part is the 'accelerator pump (power plunger).' I do not see this part listed in the diagram I got with the rebuild kit. I clean out the junk underneath the float.
If it were me, I'd start over and check the cam timing. Start at #1 TDC (#1 piston all the way up), then make sure the dots line up correctly on the timing chain. Since you mentioned re-marking the balancer, I suspect that is your trouble. You have installed the cam on some other part of the crank rotation, not TDC.
I agree with G****juice. While you may have some carb problems, I don't think they are the cause of your worst problem, this deffinately sounds like an engine incorrectly timed. No matter how long you work, or how many fixes you try, until you pull the front cover and time it by the book, I don't think it'll ever run right. Just my opinion, I could be wrong...................
Now after reading this a few times Before I desided to chime in on it. One thing you need to Look at is the timing Gear. When Installing a New Gear And If it is a ALUM gear It Must be Heated before Installing it. Other Wise IT WILL come Off.. If the gear wasn't heated It may have Walked and This will mess with Your timing. Because what is happening is the cam is Now walking back and fourth. And can Play all kinda Heck with Your dist. ( dist.gear, timing, Cam gearing for the dist, Mess with the Base of the Lifters as well) so just a little more food for thought.
Thanks for the help everyone. I believe that I installed the cam when the engine was at TDC for #1. Look at this picture. I took this pic because I was asking someone online how to turn the engine over so that I could get to the bolts (showing them what I was dealing with). If I turned the engine over so that I could get to the bolts, it seems that the marks would have been lined up. I am NOT positive on this, but I believe this is where #1 was when I pulled out the crank: So when the marks line up, the engine should be at TDC for #1? If I put the balancer back on when they are lined up, then the mark on the balancer that lines up should be the correct mark to use when timing? The balancer also already had 2 or 3 marks on it when I bought the truck. Do you think that I should try adjusting the valve lash first, or just bite the bullet and start pulling stuff apart? If this is what I should do, I'll start on it tonight.
Hi Twisted6, When I brought it to the machine shop to have the aluminum gear put on, I told them that they couldn't just press it on.... told them that they had to heat it. I left the directions from the manufacturer too. I hoped that followed the instructions... if the marks don't line up, then I guess I'll know that they didn't follow them, right?
If the gear wasn't heated What happens is the Cam will shave out the center of the Gear. then It becomes a Lose fit. And In a very short time it will walk off the cam. It will not effect the timing DOTs in anyway. It is always best to Mech. fasten the Cam gear to the cam. When In dout. This can be done one of two ways. Either a special screw & washer set-up, Or you can drill & Tap along the to matting points. ( of cam & Gear) Useing a small Allen Pipe plug 1/4 or 3/8 dia.This will hold the Gear In place and it won't walk off the cam.
the power plunger is the big hole second farthest away from the throttle bore with the gold j shaped hook on top. underneath the metal spring retainer is a diaphram. this often pulls off the center shaft.
Hi Twisted6, Looking at the cam with it installed, will I be able tell if this has happened (If I pull the timing cover off)? Thanks executioner, I will pull it apart and see whats there.
I pulled out the old power plunger.... it doesn't look like anything is wrong with it. what do you guys think?
Yes One of two ways you can/Will tell. You will see a Lip were The cam and Cam gear come together.( the cam will look sunk In the Gear Not flush Like you see now.) Secondly you will have more end play in the cam. You may also see a difference in the Tooth wear patteren.
executioner - I replaced the power plunger. I was curious and pulled the other carb apart - everything inside of it looks brand new. Could I just used the metering rod and main jet from the 292 carb and put it in the 'new' carb?
should be no problem. i am not a big fan of mixing and matching on carbs im not that hip on. i usually just rebuild whats already there and not try to reinvent the wheel. thats just me though.
I was in San Francisco for a 1.5 weeks for training for work, so I just got around to pulling off the timing cover tonight. This is what I found. and in terms of the gear walking off of the cam: what do you guys think? Thanks for the help.
Gear looks just fine. And it also looks like it was heated before the Gear was pressed onto the cam,Reason I say this is because their are no cam shavings/Curls between the two.
Hey Larry, I was looking at the end of the cam - it looks like a there's a woodruff key or something in there. I looked at the old cam and there's a slot in it for a key. Do you think it is necessary to drill and tap the cam/cam gear? Should I just do it to be on the safe side? Here's what the timing mark alignment, distributor and lifters look like: Looking at the lifters, it looks like they are where they need to be to adjust the #1 ex/in, #2 in, and #3 ex, which is what you adjust when #1 is at TDC on the compression stroke. So I believe that the distributor needs to be rotated 180 degrees. Thanks for the help
ok... now I'm confused... I stuck a rag in the #1 sparkplug hole and turned the engine over. When the rag was spit out of the hole, the engine was on the compression stroke for #1, correct? This means that the #1 cylinder should be at (or near) the top of its movement and the following valves are ready to be adjusted: #1 Intake & Exhaust #2 I #3 E #4 I #5 E This is what the lifters under the the side cover closest to the front of the engine look like: To me, this confirms that #1 is set to fire. When I look at the timing marks, though, this is what I see: When I turn the crank one rotation (until the timing marks are aligned), I think the #6 is on its compression stroke. Which means that that the following valves are ready to be adjusted: #2 E #3 I #4 E #5 I #6 IE Looking at the picture below confirms that #6 is firing I believe: When I looked at the timing marks though, they are lined up. At first I was thinking that the cam gear was install 180 degrees out on the cam. How can this happen with a woodruff key?
Actually, your crank is rotated 180 from the cam. Your crank achieves "top dead center" twice. Once on the top of the compression stroke, and once at the top of the exhaust stroke.
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