400 BB build issues

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actually i did clean the radiator using the distilled vinegar method and hot water, got some crap out but not alot it was pretty clean, I was in the process after the breakin to flush the block and heads to git rid of any remaining crap left behind, so motor, trans and front k-frame are all out, not fun by yourself btw



pulled the intake, and pulled all the plugs out, hooked up the compression checker hose ( pulled the valve core out) made sure it was a tight seal, pulled the rocker gear so i would have to keep rolling the motor over for tdc, put 110psi to it and i heard ait hiss from all eight cylinders, but no bubbles...........not a single damn bubble, I am thinking about putting a thermostat in it and running it on the "factory motor stand" and run it, other wise i pull the heads take them to the machine shop tomorrow, have them pressure check, hopefully at no cost to me since they have told me with 2 magnafluxs that they are good and then I dumped soo much $$$ into iron.... frustrating, I am open to any ideas and suggestions guys,

also all i did was open up the smaller source housing ports to gasket match the block, its a GMB aluminium pump, and is a standard fin design, and from the pictures i have found on here and Moparts its correct for clock wise rotation. whats the difference between the mr gasket t-stat and a super stant ? I double checked in a pot of boiling water and the "turbo t-stat" and it still opens right about 180, super smooth and takes about a minute or two to fully open. I have a giant 28" wide 20" tall 2.5" thick 3 core ( core dimensions) radiator in the garage that needs about 2" off the overall height and thats about a wide as i can go due to the design of the front kmember running right into the bottom of the front core support.

I did put liquid teflon on the whole length of the bolt when I ran them in, I might switch bolts for studs in the future.

-Mike
 
I would not pull the heads again. what do the spark plugs look like, and what part number, try colder. if u use a thermostat, always drill a 1/8" hole in it and test it in a pot of boiling water before install. I do not think a mr gasket therm. is a must, and any therm. is a must, and I always look in the radiator while it is running before it gets too hot to check flow, u should see the coolant flowing well. always have the belt on, and I know u used a box fan, use that and a fan on the water pump. is the ignition timing in the ballpark, is it lean?
 
the plugs are black, it wouldn't idle on its own below 1800rpms, and was running super lean ( in the 16's) on my AEM wideband, but when you hit the throttle and shot fuel down its throat it would greatly richen (10-11's) I tried the spray the break cleaner around everything to check for leaks, I couldn't see any change on the tach, but then again it was around 1800rpms and about 25in of vacuum. the plugs are XR5 NGK's, and I alway put 1-2 hole to help burp and never had an issue, but i will put a t-stat in, put it all back together and see what happens,

-Mike
 
I think xr5 is 1 step hot for 9.8 but if they are black deal with it later. how long does it run before it blows out the radiator? I would try to richen the carb, or gently constantly throttle up to like 2700 rpm and down to 1900, to richen and help the cam and lifters, assuming they are not rollers. fire it up with no therm. and no rad. cap and see how the water flows.
 
There's so much conflicting information here... Use a thermostat, don't, open the cap, don't.. Geeze.

We need more information. Was the block machined or checked or inspected prior to assembly? What was the condition of the engine prior to any machine work? You could still have combustion pressure in your coolant jacket if the deck is warped or pitted or damaged. IF it's combustion pressure then it should bubble right from startup and your air test should have shown something if you had the rad hooked up with coolant in it.

Otherwise, do as others have suggested. Top it all off, put a small hole in the tstat, burp the rad by squeezing the upper hose a few times to make sure air bubbles escape. Then fire it up and make sure the coolant is moving -- then close it up. If the engine won't idle well, you need to address that quickly while it warms up... Get the idle mix dialed in better, you've got the wideband to check it. If the cap or neck or hose blows off then. You've got some bigger issues.

The water pump is also suspect, so it might be prudent to fix that.. You say grinding it fixes it, but what if it didn't?
 
phreakish- post #1- 906 heads decked to clean up, block decked to clean up. volare said he ground/ported the water pump housing to match the block(sounds good to me) , not the water pump- sounds like u are not up on big block mopar. my engine runs below 212*, so it does not need a rad. cap
 
Marcohotrod said:
phreakish- post #1- 906 heads decked to clean up, block decked to clean up. volare said he ground/ported the water pump housing to match the block(sounds good to me) , not the water pump- sounds like u are not up on big block mopar. my engine runs below 212*, so it does not need a rad. cap
Click to expand...

Must have missed that, the drawbacks of reading from a phone. It does sound like things are squared away.. Though personally I would suspect the pump to an extent being that it's a known anomaly.

Even with an operating temperature under 212 the inside of the engine can run over that and cause local boiling. Doesn't take an expert in big blocks to understand that.. The resulting steam can and will push coolant out with force if not pressurized by a cap. Your engine may not do that, but it is probably in a better state of tune...

Every engine can be different and with the obvious tune issues (black plugs, idle issues) it could get hot fast.

Being that the heads have been checked several times already, I'd begin looking elsewhere. Cam timing perhaps? I've had engines off enough that they had the exhaust glowing in short order at idle.
 
Volare_4life said:
the plugs are black, it wouldn't idle on its own below 1800rpms, and was running super lean ( in the 16's) on my AEM wideband, but when you hit the throttle and shot fuel down its throat it would greatly richen (10-11's) I tried the spray the break cleaner around everything to check for leaks, I couldn't see any change on the tach, but then again it was around 1800rpms and about 25in of vacuum. the plugs are XR5 NGK's, and I alway put 1-2 hole to help burp and never had an issue, but i will put a t-stat in, put it all back together and see what happens,

-Mike
Click to expand...


I guess I still don't understand. It runs hot. It won't idle. 1800 is not an idle speed - you're way past the idle circuits in the carb. You say "there's no lag" but it's already 1100rpm above idle. The engine has some other issues you need to take care of I think. Did you do a compression test or just pump your airl ine pressure into the holes? Did you build it or you got it built? Something's way off here and it's not the cooling system or spark plugs.
 
High idle, and that lean....? Vacuum leaks? Like a vacuum port not plugged on the carb? Man, this just sounds all kinds of wrong...

What's your timing?
What kind of carb?
jets?
power valve?
floats high?
carb gasket sealing?


Do you have another video you can post of it running with sound?
 
actually i did clean the radiator using the distilled vinegar method and hot water, got some crap out but not alot it was pretty clean, I was in the process after the breakin to flush the block and heads to git rid of any remaining crap left behind, so motor, trans and front k-frame are all out, not fun by yourself btw
Click to expand...

Well, using vinegar will only do so much...I meant taking it to a radiator shop where they physically melt of the braze on the side tanks, physically brush out the cores after a caustic bath, and rebraze the tanks on and pressure test it.

Once upon a time, I installed a new top end (heads, cam, rockers, intake) on the 306 in my Mustang...it didn't run hot, but a little warm on the 3 core radiator I installed after first putting that engine in several years before. I did the swap, and during break it, it puked a little more than I liked, and constantly ran hotter than I liked...probably about 205-215 on a hot day. I had a good cooling fan and I thought it was just a little dirty cuz the coolant in there was a little off color. I did a flush with the flush kit you buy at the store, it puked out a bucket full of slime and I thought I was good. Car still ran hot. I took the rad out and had a shop clean it. When I picked it up, the guy behind the counter told me it had a 60% core blockage...everything below the top 6-8" of the cap was filled with calcium.

New 50/50 mix of prestone and distilled water dropped my temps to 185-195 on the same Texas summer days with the same fan. So, if yours is still puking rusty water, you might have more crud in there than you know.

You're positive there's no oil/water mixing anywhere?
 
After all the stuff we had on the slant overheating thread.... :D

I think he is getting steam pockets in the heads like my 440 Demon did before I put the 195 T-stat in it. I also drilled the little hole in the outer ring so the air could bleed out easily. You want the cap on so you can keep things under pressure and won't boil so easily. There is a bypass hole below the thermostat in some of the pump housings. I plugged mine with a 1/2" expansion cup after making sure the hole was the proper size. You definitely want all the air you can flowing through that radiator.
 
well I feel stupid...... really stupid, after all the bullspit about this carb, when i bought it it was "running ready to go" so i swapped the plastic pump cam arms for metal, turned on the aeromotive pump and it leaked checked good..... the freaking base gasket to carb body was the wrong one and caused the super lean condition !!!!!!!!!!!!!!!





now all i have to do is get the front end back under the car, but since we just brought our brand new baby boy home from the hospital today, might be a bit longer still



-Mike
 
Congratulations on the new baby, glad you finally figured out your issue. We look fwd to seeing the fixed and running BB in your F body.
 
well its all back together and running amazing, except for the trans, 1st and 2nd shift great, 3rd and reverse slip alot, now i adjusted the bands per the transgo TF-2 instructions, but something isn't right I have my ATSG 727/904 rebuild book, and from what i gather all i need to do is retighten the front band, and it should be good to go, is this correct ? I mean 72in lbs on the front kickdown band is not tons of pressure,

Mike
 
well I adjusted the kickdown band took it out, had reverse, but no third at all, then once it got warm ( driving around the neighborhood) still no third and reverse started slipped and shuddering, so it looks like shes gonna be coming out.............not fun in a cramped Volare, torn down and rebuilt.... but first to test the front clutch pressure feed hole just to eliminate that, any recommendations for who to go through for parts to rebuild the trans ? I really wasn't looking to sink a ton into it, I have been planning to swap a T-56 in come tax return in January/February time frame, other wise its gonna be an automatic for a bit longer,

-Mike
 
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