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Need input on Carburetor

How old is the gas? Old gas doesn’t smell too strong


Or burn
 
Brand new gas, been driving it lots lately to try and work through these issues. It seemed to thick to be gas
 
both of those test are valid, and would help pin point the problem. On the compression test what were the numbers for 4 and 6 ? Do you know the casting number on the heads?
 
Every cylinder was 120 +/- 5psi. Idk the casting number, I’ll take a peak later today if I have time
 
Don’t have time to pull the valve cover to check casting numbers and won’t for few days. Put looked at shapes cast in the head and referenced the online guide, looks like “N” in the guide. Not sure of these are good or bad heads?

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Yeah 882 no bueno, so I am gonna just jump right up there and say cracked head, right between the valves. If in fact you pull these heads, DO NOT spend any money on them. Either find a better set or get some new aftermarket ready to go. Machine shop cost for guides new valve springs and machining will be dam near what nice new performance heads if not more in some cases. If you are thinking about scrounging some heads, lets us/me know I will provide some casting number to look for. But 1 rule thumb I use, look at area by the short head bolt if is basic straight for the length of the head, they are normal castings ( some say hd) if that edge scalloped they are light weight castings, stay away from light casting.
 
If it's carb related.... I had great luck with the OEM 4 barrel carb + automatic choke
 
Wes Harden said:
Yeah 882 no bueno, so I am gonna just jump right up there and say cracked head, right between the valves. If in fact you pull these heads, DO NOT spend any money on them. Either find a better set or get some new aftermarket ready to go. Machine shop cost for guides new valve springs and machining will be dam near what nice new performance heads if not more in some cases. If you are thinking about scrounging some heads, lets us/me know I will provide some casting number to look for. But 1 rule thumb I use, look at area by the short head bolt if is basic straight for the length of the head, they are normal castings ( some say hd) if that edge scalloped they are light weight castings, stay away from light casting.
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Well the engine is a jasper and had a 3 year warranty which it is nearing expiration. Just not sure I really want the truck touched by the idiots that did the work for the previous owner as they clearly had no idea how to swap a motor, loose bolts, stuff installed backwards, bolts striped out.. it’s been a mess trying to unf*ck this truck
 
oh wow sorry to hear is finger F'd by idiots , never been impressed with jasper either. That make me even more confident the head is cracked since it has been machined at least once. we have a member here @kennyw he might be able to help out with parts in your neck of the woods, at same corner of the country.
Might be worth considering a whole engine used or otherwise. Not sure Jasper will honor warranty for not original purchaser.
 
Would a cooling system pressure check reveal this somehow? you’d have to see coolant entering the #4 cylinder right? Maybe pull the plug with piston at TDC and see if coolant comes out of the spark plug hole? And a leak down test would pressurize the cooling system? Or is there anyway to confirm the head is cracked before jumping to conclusions?
 
For now I’ll assume Jasper knew to put thread sealant on the head bolts. Is it possible that if the intake manifold bolts didn’t have sealant on them that could be a leak? Oil is right at the full line and perfect color, no odd smells. Just did a home made pressure test using a ball/bike pump, highest I could get it to pump was 11 psi, then used a tire pressure gauge to check psi, (see pics for my shade tree setup lol.) Below are the results of the first test. I also rechecked spark plug in #4 cylinder, the wet one, it has been sitting for a couple days with no cranking, plug is dry. Cooling system pressure check:
Initial psi: 11 psi
2:00 10 psi
4:00 10 psi
6:00 10 psi
9:00 9.5 psi
11:00 9.5 psi
13:00 9.5 psi
20:00 9.5 psi
It occurred to me i may have lost a little bit of air everytime i checked it. So I then performed a test where I pressurized it to 11 psi, waited and checked it less frequently:
20:00 9.5 psi.
30:00 9.5 psi
45:00 9.0 psi
60:00 9.0 psi
90:00 8.5 psi
Is it possible that the cracked head/head gaskets only leak when it’s warm or the engine cylinder is under pressure/vacuum?

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Yes it is possible that heat is needed, esp if it is a hairline crack in the combustion chamber. Also not all bad head gaskets leak water into the oil. Be cause the engine compression is much higher than cooling system pressure a head gasket could exhaust gas into the cooling system, but not coolant into the cylinder. At in the beginning, if left unrepaired it will only get worse.
Please get and use the block check I posted above. It will tell us for sure if we need to worry about cracks or bad head gasket.
Sealant on head bolts while a good idea is not 100% necessary. Yes the intake manifold bolts can leak oil and or coolant.

Checking out your photo, loose the plastic fuel filter. up there at the intake in the fan wash it is a fire hazard. best place is at the inlet to your fuel pump. Use a high quality soft line from the steel line to the Holley. Pref steel braid with AN fittings but that is more than a few dollars for sort section of hose. Be sure to inspect that hose, a lot. At least every oil change.
 
Copy all that good info, the only reason I was dragging my feet on the test kit you posted is that I just added 1.5 gallons of coolant and haven’t been driving it while I’ve been working on some of the other diagnosis techniques, so I was thinking it may be watered down and I may need to drive it more to get exhaust gas to circulate through the coolant more to test positive.. I’ll order one and repost
 
no you may have to lower the level in the rad a couple inches. But you'll remove the cap put the test cylinder in the rad opening, put test solution to line on cylinder, start engine and let it idle. If you have exhaust gasses in the cooling system the test solution will change color to yellow.
 
fyi I do not benefit, if you purchase from that link, just easiest way to show tool
 
Holley carbs, out of the box, have a very generic tune..
But every engine is going to have different needs.
Power valves, discharge nozzles and accelerator pump cams are all available to tune them.
As stated, make sure your timing is correct first. Stumbles off idle, acceleration are usually within the discharge nozzles and pump cam tuning, cruising stumbles are power valves and/or secondary vacuum control springs.
 
FYI you aren’t going to pressurize the cooling system and get coolant pouring out of number 4 spark plug hole. Cracked heads introduce a very small amount of coolant into the combustion chamber when warm and operating. You really need a cooling system pressure tester that goes on in place of the radiator cap. The way you are doing it depending on the psi of your cap is just going to bypass the cap which could be where your pressure loss is.
 
Chickntrk said:
FYI you aren’t going to pressurize the cooling system and get coolant pouring out of number 4 spark plug hole. Cracked heads introduce a very small amount of coolant into the combustion chamber when warm and operating. You really need a cooling system pressure tester that goes on in place of the radiator cap. The way you are doing it depending on the psi of your cap is just going to bypass the cap which could be where your pressure loss is.
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While a cooling system pressure tester is the way to do it, I have tested many many cooling system in a similar fashion to @HawK5. Granted I was never looking for coolant in the combustion chamber. This way test your cap at the same time. My set up uses a regulator and a compressor. On a side note it worked great to fill up a bunch of soccer balls when wife couched girls AYSO, got them all evenly inflated in no time :saweet:
 
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