I am swapping out 60"s 283 for a new 350/290hp crate motor, for a friend of mine, OK. new motor ,used Edelbrock Performer dual plane intake, NEW edelbrock carb, used manifolds. Problem is Right side manifold runs up to 500 degrees, left side only 275, so is 500 too hot or 275 too low ? and why ??????????? all while the temp at the thermostat (block side) is only 165
How does it run? The exhaust temps at idle on SBC will never be even, and when measured like that tells you nothing. Read the plugs, I bet you are running rich, have not enough timing or both. From a mag article: Bottom line: Don’t rely on EGT temperatures to tune a spark-ignition engine. “The best thermocouple in the engine is the spark plug!” maintains Duttweiler. “Even in today’s NASCAR world, plug reading is critical. It will tell you exactly how hot a cylinder is.” For Brulé, a heat gun is “nothing better than seeing if a rocker arm broke—say one cylinder is 240 degrees while the others are all around 550.”
first, I'm a retired truck mechanic, now make a living fixing ''things'', including 'old' cars. My original concern, was the Eastwood high temp manifold paint got burnt off right away during initial run-in, only on the right side in the center. It did so using the old Quadrajet , also on a used Elelbrock, and also on the new Edelbrock. On the first run down the road, after it warmed up it started to pop and backfire during acceleration, So, I will put away the temp gun, and buy some new ;clean; spark plugs, and points and start over.
Is there a heat riser in one manifold? One side of the carb usually feeds two cylinders on each side. Front and rear on one side and the two center ports on the other side. See if there is much difference at each port.
no heat riser, just straight pipes & gl*** packs, but, I dropped the pipes, hadlittle effect, temps were a little lower, but the same temp difference. It has dual plane intake, the hottest is where the center ones are on the right.
I know they say you dont need an adaptor with a 2101 intake, but you do. You will have a vacuum leak. It is a flat plate. Sent from my SM-G900P using The H.A.M.B. mobile app
I have a question on the water p***ages at the rear of the head, on the 283 they were blocked off with this Elderbrock Performer intake, also on this new motor, and I see they make manifolds with rear p***ages, Now, this new motor is built for 73 to 85 cars and lite trucks, question : would this 'motor' require those rear p***ages ???? Just trying to eliminate things
Take the little covers off that let you get access to the metering rods on the carb and check the rods. I have see 3 different edelbrock carbs with Metering rod problems. One had one of the metering rods bent partially blocking the jet making it run lean on one bank, one where the metering rod was broke off completely at the top where the spring attaches and on not attached to the spring that holds it up. Both of those plugged one jet completely and caused a major lean condition. The one with the broken rod, also a 350 290 motor, burnt the rings off the pistons on the drivers side bank. Lean is no good.
jets look good to me(rods) in fact I swapped them around just in case, the carb shim, if I recall....goes on the manifold first without a gasket ??
only got a few minutes. right now.... I Read where I need a different intake gasket for use with aluminum intake . true or not ? the one I have is blue, one to use is brown or black w/ silicone ridges ????????
Nope. GM never found them necessary on anything sold at the dealership. You have a problem and it is not the rear water p***ages in your heads. Keep looking and you'll find it.
A carb plugged on one side (or vacuum leak on one set of runners) sitting on a dual plane intake would make two outside cylinders on one bank and two inside cylinders on the other bank run hot, not all four cylinders on one bank.
You have to run the gasket that matches the intake on that side and the gasket that matches the carb on the carb side. I ran into that on one of my rigs.
Spray some carb cleaner or WD40 on the intake gaskets on the hot side and see if the RPM changes. If it does you have a vacuum leak.
Iwill change the points and in stall carb. may be I get down today... as I have local 'cruise=in tonight, thanks again guys !!!
I suspect some type of vacuum leak, possibly the intake gasket. It could be an external leak that will show up by spraying something on the gasket. A leak at the bottom of the manifold which would be inside the engine or a leak between the two ports.
It can be difficult to get a good seal between the head and the manifold. I like to glue the gaskets to the head with 3M Super 77 adhesive so they don't move. I don't use it on the manifold side. Make sure the gasket used fits the ports on the manifold. Some gaskets are larger on the outside so they are somewhat stronger. Aluminum expands and contracts at different rates than cast iron. Make sure the surfaces aren't extremely smooth so the gasket can grip.
''I like to glue the gaskets to the head with 3M Super 77 adhesive so they don't move. I don't use it on the head side''...................please explain
EVERY THING IS GOOD ! I had the wrong base plate and gaskets for the carb, wrong points (dwell meter took a **** , back to just the good old feeler gauges ! Still got hot at first, but after a bout 10 miles it was within 100, so, I think with more miles and NO heat gun, should be OK ! thank you guys, for the help. that's 'we' come here !!!!!!
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