Had a motor once that was running funky and doing the same thing, some headers were glowing, others were alot cooler. After many days fooling with it, while it was running, sprayed some carb cleaner down the carb and it ran better??? Turned out 1/2 the carb was dead. SBC just like yours. Don't know if it will help you, but that was my problem.
What lux said, but i remember it by EBOSI IACSE.(E-boss-e, i-axe-e) exhaust begins to open, set intake. Intake almost closed,set exhaust.
On a big cam theres no other way. The events are so spaced that the adjustment window is really narrow at TDC, the way LUX says it you are sure to be on the base circle.
I would go to a 650 Demon double pumper. Fixed my issues..... I wouldn't open that engine up until I did a compression and a leak down test at temp., check if I stabbed my dist. off a tooth at tdc. Inspect that my firing order is in order, and check gap on the plugs. Do a lean drop on the carb, verify its getting proper fuel pressure, and inspect/adjust floats, pull the valve covers off and spin up the oil pressure and see if both heads are oiling properly if concerned about oiling,and go from there based on results... Your timing sounds off the charts to me I am used to a good 10-12 degrees with vacuum advance unplugged at around 650-750 rpms. Sounds like alot but I can do it in about 20-30 minutes usually.
What's the water pump off of ?? I've known a few who have tried to run Corvette aluminum water pumps and some of them are for serpentine belt system so the impeller turns backwards from conventional v-belt systemwater pump. Just a thought
By the way I've seen a lot of motors make the headers glow on the breakin. If it sounded ok , no missing or popping, I'd disregaurd valves/timing and lean toward a cooling problem.
I use this sequence to set my valves. I've used it for every thing from stock cams to .700 lift rollers with no problem.Works great on fresh hydraulic motors that are cold and have never been started. Just turn the rocker arm nut until there is slight tension the lifter spring and no slack. Put the valve covers on and go. On solids use a feeler gauge and this works good for a quick touch-up on solids when the motor gets some miles on it. #1 up on top dead center set vavles: ~~~~~#6 up on top dead center set valves: EXH: 1348.............................................. ............EXH:2567 INT: 1257.............................................. ............INT:3468
I would look at this also,...... after you have headers coated they recommend you dont run them on a break in of a new engine for this reason.. will burn the coating right off them one thing you can do is fire the motor and watch the headers....when they start to glow, reach over and push on the accelerator pump lever.....not the throttle lever ....the little lever that pushes on the accelerator pump.. if the header glow increases...its from unburned fuel burning in the pipes, it will increase because you just added fuel to it with the pump shot...... if the header glow decreases , you are running lean, and the pump shot just richened it up .....you need to look for vacuum leaks, to small a carb or carb issues, valve train issues etc......but it will pinpoint which way it its off. Ii think the overheating issue is a seperate problem.
Sounds like a timing/valvetrian or a carb issue to me...or BOTH. With a cam that big, and likely a regualr old Holley 600, you're running a 'stock' power valve in the carb and it will need a different one, for sure! The power valve is supposed to open under a load as the vacuum drops to a specified level...but with radical cams, the vacuum is already low and the power valve opens prematurely (often at an idle!), dumping excess fuel into the manifold before the engine needs it! That excess fuel could be burning off in your headers, as distrubuted to the 'problem' cylinders by your dual plane intake manifold. Just a thought. As others have said...check your rocker arm adjustment and cam timing...as well as your spark timing, too.
OK, I didn't read all posts. So......If you idle it down for a second, does it sound good? Does it rev/respond like it's on all 8 cylinders?
That was my 1st thought. Problem is, with a dual plane, the bad cylinders would be 3-5-2-8, or 1-7-4-6.
He said that all the plugs are black. Since they are all the same don't think it is a fuel problem at this point.
It sounds normal to me a new motor has a lot of cyl temp make sure you don't have a vac leak and run it shut it down run it shut it down, did they bore and hone with a torque plate? what piston to wall clearence? Try running a leakdown on the motor if that's good run it it will be OK!
The distributor might even be a tooth off, that's more likely to happen unless you have a degreed crank timing gear that is off a notch. I generally like to keep 'em running for cam break in even if I have to run the garden hose over the radiator tanks. I agree on running valves on the loose side, richening up the carb is fine too. Better than running towards a lean condition and easy enough to adjust later. Bob
18"-19" of vacuum at 2200 rpm on a well sealed engine -gaskets, rings, valves. At idle, if you can get it under 700 rpm it'll run 8-10" with that big of a cam. Is the thermostat right side up? Did you test the thermostat in a pan of water on the stove? You may be fooling yourself by shutting the engine down at 200 degrees with a 195 degree thermostat. If you have a mechanical temperature gauge that follows the heat fairly fast you can watch the temp go up and down until the engine becomes thermally stable - fully warm. When it does this the heat will swing past the thermostat rating, then under, then over although not so far each time until it settles out. My pals recently acquired 302 SBF powered 46 Ford sedan had the cam off a tooth or two when he got it. The C4 trans wouldn't shift into third due to low vacuum. About 12" at idle and 15" at 1500-2000 rpm was as high as it would go until he got things straightened out. Guessing here, but the cam is probably around 265-270* advertised duration. Somewhat common to see headers glow a dull red during a 2000 rpm cam break-in. Usually in the subdued light of early evening.
When I fired my Ardun with 6 97's for the first time same thing happened . Headers turned red . Turned out way too rich and was still firing in the heated headers..........
Wow!!! Thanks, guys! I've learned more on one thread just listening that in all the latest bench racing sessions with my friends. Thanks, Mike
First, what do you consider overheating. Second, I didn't see an answer to my other 2 questions from you
I would run a compression test. If the lifters were not pumped up before instal, they might be adjusted too tight now.
The way I make sure hydraulic lifters are full of oil is to submerge each one of them in a can of clean oil, then use a pushrod to push the plunger down a a couple of times. When you can't push the plunger down anymore they're full.
Here is what has me confused... Why only the center 4 tubes. Typically, If we have a "hot" run in, the whole damn header gets hot. and both of them at that. Someone refresh my memory here...aren't 400 head gaskets exclusive to the breed due to the middle 2 cylinders being siamesed? (or something to that error...can't remember.) Grouch is right..if it were carb related, it would be 2 inside and 2 outside. You can argue "lean runers" versus "fat runners", but again, it would affect the header in an offset pattern. a timing issue would likely be "across the board" and it would run like kaka in general. here's a thought...if he adjusted the valves and got intake/exhaust confused on the center two (it goes exhaust, intake, intake, exhaust, exhaust, intake, intake, exhaust) or oOOooOOo when You look at it from a valve standpoint. if he used The eoic method, he may very well be hanging the center 4 valves open at some point. and the intake valves wouldn't be opening all the way. it would also be rattling to beat the damn band, but if the exhaust isn't hooked up, or it was dismissed, then that could be it. or, the gasket is blown between the center 2 cylinders...but that happening on both heads simoutaniously is pretty unlikely...unless the head gaskets are wrong.
ok , he must have gone out . no responses . ****** if i were you i would take a break (to close to the forrest to see the trees) , when that is over , go thru everything like it was a VIRGIN . i have to do this when i get to your point . lots of times i will find it in my sleep ! no kidding . the frustration of where you are is mind boggeler . have a beer , smoke one , just take a break . you dont want to hurt the thing !!! works for me , i hope it works for you ...............good luck.... steve
ONLY DIFFERENCE IN 400 GASKETS ARE THE CUT OUTS FOR THE STEAM HOLES...sounds to me as if he's running too tight on the valves...causing them to be opened and burning raw fuel in the flange area...also on the 400 sbc, the center tubes WILL ALWAYS RUNN HOTTER!! this is due to the lack of water flow around these cylinders...yes they are siamessed..touching in offset stager...anything above 220 is hot for a 400....been running 400 sbc's for 15 years, blown, tunnel rammed ect..every combo i have built runs red hot on the center tubes during breakin..check at the basics, no one likes tearing off the timing chain cover and pan to start there..start simple, and then work inward...also i'ld walk away from a 195 stat..run a 165 or a 180 MAX....the motor will reach a happy temp IF YA HAVE ENOUGH COOLING FRONTAL AREA WITH ENOUGH AIR MOVEMENT....good luck.............
Why not try something old school like a chiltons va***e chart .Then install a va***e gauge and see which chart matches your dilemma . But i think its tight valves .
That's why I asked earlier on, how the thing sounds. If it's responsive, or is hitting all 8.... He's gonna have to answer these things sooner or later if he wants help fixin it (if it even needs fixing). So far he's been a bit vague. 2200 with no load and the power valve shut will tend to warm the pipes a bit. Especially thin headers. I'd be a lot more worried if it were glowing some cast exh manifolds. Again, how's it sound?
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