I'm kinda stumped here....The engine wants to run hot, and I can't figure it out. It's not boiling over but runs around 230-235ish while driving and will get to 240 (next dash up from 220) when idling. Engine actually feels pretty hot and hoses are tight as a drum due to the pressure and heat, but not boiling over.

Fan is running constantly after it warms to 220 and water is circulating. New water pump, temp gage sender, radiator is a Autozone replacement about a year old. Doesn't seem to matter where I set the timing at. Air dam in place.

Engine does smoke a bit which is another worry. Kind of a whitish tint to it, and droplets of water can be seen shooting from the tailpipes when initially started when cold. As it warms up the water disappears and the smoking seems to become fainter. At first I was thinking bad head gasket (ugh), but no coolant loss that I can tell. I even put a peice of tape on the coolant resivoir at the coolant level and check it after the thing cools down, and it goes right back to the mark.

Engine seems to have plenty of power when driving it but hogs gas like no tomorrow. I drove it for about a half hour or so before work today and it didn't overheat - I was watching the gage closely.

If I had to guess, the engine has around 3 hours idling while I was trying to set timing and carb, and I've driven it maybe 30 miles now. I pulled all the plugs and they look all look black. I figure it's because it was running pig-rich when I first started it and I think it still is, just not as bad.

Any ideas? Sorry this is so long but I want to give as much info as I can.

 

I really dont know what the problem is, but Ill throw out the first thing that comes to mind. First do your heads have the steam holes drilled in them? if not they need them. And the only other thing that I noticed is that you have a high performence engine with a pretty big bore, your gonna need to upgrade the cooling system. Your gonna want a peformence pump and an aluminum radiator along with a low temp thermostat and a fan that turns on at like 180 degrees. Just some ideas because my friend had simalar problems whe trying to run the stock cooling system on his 406 in a 80 camaro as soon as he upgraded the cooling system it ran 5 times better. But like I said I dont know if this will fix your problem I just no it will help your car perform better. Good Luck.

 

Just a thought, is the timing retarded too much?

 

Sorry, forgot to mention that. Yes steam holes were drilled or at least it says that on the engine spec sheet I have. I can set the fan to turn on sooner, but it just takes longer to creep up to 230 that's all.

So you think maybe going to an aluminum radiator will help?? I have some off-brand (CAT) high performance water pump on it already. I have considered changing to a 160 degree t-stat, but I'm skeptical as to if it will help or not. It has a 180 degree in it now. I thought there were others around the boards here running simular engine setups on this board that still run the stock cooling system?? If not, then you may have something there.

Rick - I have the timing at 28 degrees advanced at idle. Runs like crap at anything below 20 degrees. That was my initial problem when this all started. I was trying to run it at 18 degrees advanced, and it runs hotter then...

Thanks for the replies.....any more thoughts??

 

When I had the 406 in my 85 I drilled an extra 1/2 hole on each deck between the middle cylinders, had to make holes in the head gaskets also..the heads already had them(world 200`s). These modifications were outlined in lingerfilter`s book and I had heard of running hot problems with the 400. At first the engine ran 190-210 in 80 degree weather, after a while it ran 160-180. On the freeway way it would get down to 140, turn the air on max and roll some side streets...right to 220 in no time. Bottom line is your NEW 406 will run hot,new motors have more friction and do run 15-25 degrees hotter for a short while. I`d think 500 miles would be about the point you`d see some changes. I`ve always had a three row brass/copper in mine and that same radiator is cooling my .100 over 454 today just fine,80* here today. Your radiator probably isn`t at all efficient anymore if it`s original, scale build up will block the heat transfer. good luck

http://members.cardomain.com/greezemonkey

 

28* initial sounds a bit much to me i'd look at the timing, ignition and cam

 

Maybe you've got an air bubble in the cooling system?

 

Make sure the spring in the bottom radiator hose is not too far one way or the other. Should be able to rev the engine while watching the bottom hose to see if it collapses.

 

Right now I'm running the stock radiator with no cooling issues.But as greezemonkey says, yours might not be as efficient. Ive ran it hard and it never gets over 180* I am usung a washer in place of the thermostat. Im running about 18* initial timing at the moment.
But I have no acc. no power steering and the weather has been in the 70*-80*
How hot are your headers getting?

 

I ran a 400 for about 12 years; most of it in Memphis, where it's 90 degrees and 90% relative humidity for about 5 months out of the year. I ran the air non-stop probably from late March to early October. I never really had any cooling problems. I would even do things like drive to the race at Talladega, and sit there for 2 hours in traffic with the air on, for the (formerly) August race. Anybody that's been in that part of the country at that time of the year knows what I'm talking about.

I had the stock single electric fan, the stock 230 whatever degree fan switch, 180° thermostat, a stock radiator from some later model car (aluminum & plastic), 70/30 water/AF mix, all accessories, and otherwise just made certain the whole ducting system for the radiator was always intact and free of any blockage. The only "modification" I ever did, was a Stewart Stage 2 water pump. I tried some Water Wetter once just for kicks; it didn't really make a whole lot of difference, except that the motor cooled down faster if it had been sitting and I got going again. With the cooling system this way, I could sit still for hours on end idling with the fan cycling on and off between 210 and 230°, and then literally watch the temp gauge drop if I started to drive at 40 mph or above.

Advancing the timing as far as it will go without pinging helps. Getting the mixture right helps ALOT.

New motors always run hotter than ones that have been around for awhile. I think it's just due to the accumulation of insulating layers of carbon and whatnot in the exhaust ports. Those are actually the hottest parts of the engine; the chambers are nowhere near as hot, as they get regularly cooled with fuel.

I had the latest set of heads I have coated by Dart with their ceramic coating, in both the chambers and exh ports. It'll be interesting to see if that holds down the new-motor temp thing.

 

greezemonkey – I’m pretty sure they didn’t drill any extra holes in the block deck. As far as the radiator goes, I do have a stock radiator, but it’s practically new and clean. I always run a 50/50 mix. The point you bring up about it running hotter due to the engine being just rebuilt is a good one. Maybe I do just need to run this thing for awhile and see what happens. - Thx

ede – Yeah, I agree 28* is a lot more advanced than I’m used to setting timing at. But it doesn’t seem to ping or anything when I drove it. Kinda hard to hear over the catback though.

Thing is, the shop spot welded the timing pointer on the cover, and I’m suspicious that it’s not set at TDC. I used a vacuum gage hooked up to full manifold vacuum to set the timing where it is now. I advanced the timing till I got the best vacuum w/o detonation, then backed it down till the vacuum dropped 1 inch (ended up with around 15”) , and it ended up at 28*. Seems to idle much better there at 900 rpm’s. Anything else I should check?? You mentioned checking the cam and ignition also. What should I look for?

rjmcgee – Lower hose doesn’t have a spring (I don’t think), but it doesn’t seem to be collapsing or anything.

Air_Adam – Radiator seems to be topped off, and I don’t see air bubbles when I take the cap off when cold. Not sure what it looks like after it starts warming up though.

Riley – Yeah, not having the best of luck with this. For some reason I can’t get it to time down at 18*. It’ll start to make popping noises out of the exhaust, and I just know it’s not right. I removed the washer from the t-stat housing on mine from the dyno. I’m considering putting it back in. Don’t know whether it’ll help any though. Somehow I think that if I would have just went ahead and built this thing myself, I wouldn’t have these problems. I’ve rebuilt a couple of Dodge engines in the past, including the L69 that I have on the stand that I pulled out for this engine (which ran great) and I didn’t have these issues with high temps or timing or running rich. So far as the headers go, they’re not glowing or anything like that. Then again, with the nickle plating it may be hard to tell.

RB - I don't think I have the mixture right at all, and that could be some of the problem. I think it's running rich by the smell, but if I try to lean it out further it stalls out and won't idle. I have it advanced as far as it will go. I'm at wit's end with this thing. I've never dealt with anything like it. There's gotta be something I'm missing....

I appreciate the replies guys, and if you can think of something else feel free to post it up. Definately open for advice if you have any more.

 

Have you tried taking the thermostat out completely?

 

I mean one big bubble in the engine itself, not in the rad.

The reason I suggested the air bubble, is because that happened to me when my 350 went in. Now, this was not a newly built engine, it was just being swapped in, but it had a huge overheating problem right away, because (as I understood it at the time) with the air bubble in the system, no coolant actually gets pumped through the engine, it just sorta sits and gets hot. I could be wrong about that, but thats how I remember it being explained.

I don't remember how my unlce got that bubble out though.

 

Allright, now that could always be a possibility....you may have something there!!

I'll check that out first thing in the AM. It DiD seem to not take much coolant when I initialy filled it. I reused the antifreeze from the 305 I pulled and I had a couple of quarts left after I assumed it was filled. But shouldn't it still draw from the resivoir when cooling down to top itself off? That's still above the fill line on the jug....hmmmmmm....

I'll post what I find. Thanks!

 

how would that help? you need the restriction to give the coolent time to absorb some of the heat.

 

The coolant doesn't need "time"....

But apart from that, I doubt taking out the thermostat would help, unless your pump can't move enough water through its restriction (too little coolant flow velocity). A high-flow thermostat, such as from Stewart, may help, as it would allow the coolant to flow faster.

I'd strongly suggest one of their water pumps, thermostats, and radiator caps.

http://www.stewartcomponents.com/html/tech_support/ for a good discussion of how things work.

 

well rb would the coolent not absorb as much heat if it spent less time in contact with the heat source? or spent less time in the radiator to disperse the heat in the coolant. i thought that was the idea behind restrictors in place of the t-stat.

 

Tell me what you think about this. I started up the car with the radiator cap off, just to see if the block was somehow air-bound. What I found seemed strange (maybe it isn't) is that I had the cap off for a good 15-20 minutes or so, and the radiator DIDN'T overflow with the cap off! Anti freeze just sat there.

I could be wrong, but if you keep the cap off the radiator, shouldn't it try to overflow when your temp gage reaches 230?? Mine doesn't. When I rev it with the cap off the level in the radiator drops maybe an inch and comes back up when I return to idle. But while the level dropped that inch, I was looking inside at the radiator tube ends to look for flow and I see antifreeze just trickling out of the tubes. Not nearly the flow I've seen on other engines.

When I pinch the upper rad hose at 230 degrees on the gage, I expected to feel water flowing through the hose. I don't feel any. And I was pretty much pinching it closed. Is that normal?

 

For some reason this didn't go TTT. What do you think?

 

Sounds like one or more of several things is true:

• Your temp gauge reads higer than reality, and your temp is really quite a bit lower than you have been thinking;
• Your water pump isn't pumping very much at all, and you need a new one;
• Your thermostat isn't opening very far, or is just plain restrictive, and doesn't allow much flow;
• Your radiator is stopped up

Keep in mind, a water & AF misture not only freezes at a lower temp than pure water, but also boils at a higher temp than pure water. So even though water boils at 212°, coolant requires a significantly higher temp to boil.

I'd say that options 1, 2 & 3 are the most likely, and you have all 3 of those in some combination.

 

OBTW the coolant doesn't need to move slowly. Let's think about it logically for a minute. If the coolant is moving (pick a number) twice as fast through the system, then yes, it will absorb half as much heat per unit mass of coolant. But, since there's twice as much coolant moving around, the total heat absorbed by the coolant will be exactly the same. With one significant difference: since at the higher flow rate each unit mass of coolant only absorbs half as much heat, its temperature rise will only be half of what it would be if it was moving at the slower speed; so the net temperature inside the system will be lower. Of course, the same thing is happening at the other sidde of the system, where the coolant releases its heat to the ambient via the radiator.

Therefore:
Faster coolant flow = the same heat transfer, but lower internal temp.

I have no clue how that other myth got started. IMHO it's right up there with an engine "needing" exhaust back pressure.

 

The water flow through the radiator sounds suspect.
(water pump, lower radiator hose, radiator blocked)

The timing is important. I would get a "piston stop" and verify that TDC on the timing marks is actually true TDC.

 

Try this (just incase there is a bubble in your engine):

Take out one of the heater hoses or the plug (don't know which you used here) on the intake manifold, and then try filling your cooling system. I'm not really sure why, but the coolant level goes down MUCH faster in the rad when I am filling it if I do that. I assume its because it lets air out of the system much faster. Doing this might eliminate the problem, or at least eliminate an air bubble as one of the potential problems.

Anyway, try that. Or maybe even dumping coolant directly into the engine through the heater hose outlet in the intake manifold. I haven't tried that myself, but it would fill the engine with coolant in place of air if there is a bubble.

 

OK - so by your answer RB, I think you're saying what I found is not normal. Funny thing is, all parts you mentioned as possibilities are new - The T-stat is new, the radiator is practically new, along with the water pump. Oh and the temp sender.

I know what you're saying about antifreeze's boiling point being above 212, but AFAIK almost any coolant I know of will expand when heat is added. It may not boil, but it should at least overflow I think if the cap remains off.

I put the T-stat in after this problem occured, so I don't think that would be it. The radiator, unless the engine had a lot of garbage in it,should be clear. I don't see any debris floating around. The sender could always be a possibility although it's new.

That leaves me at the water pump. It was supplied by the engine shop. So, let's say it is the water pump. Could that be the reason I have been having such a hard time tuning and timing this engine?

Better question is, have I damaged anything? I would assume if there is little or no circulation of coolant in the block, the sender wouldn't be accurate. Only blessing here may be that heat rises, and the sender screws into the cylinder head (near the top). Would there be any liability on the builder for this??.......RB or anyone else?

 

When the engine is cold, take out the heater hose outlet on the intake and try to top off the coolant in the engine. That will also help remove any air inside the engine too.
I'm sticking with my air bubble theory untill proven wrong!

 

I hear ya!!

If an air bubble is truly causing this, I'll try pulling off the t-stat housing while the radiator is full. I'm thinking if there's any air, it should be at the top of the engine right? So the coolant in the rad should start filling up any possible voids I would think. If not, I guess I'll just pour water in it till it fills up! And yes, I'll pull off the heater hose also.

I'm still leaning towards this off-brand (CAT POWER) water pump I have though. I'm still really thinking the higher than normal engine temps are the root cause as to why I can't seem to get the engine timing right, and the carb adjusted properly with water just sitting and heating up inside the block. Or at least I hope it's the cause....

I'll post back what I find out. - And again, I really do appreciate the good advice from you guys!!

 

Well, I removed the old water pump, and I was really hoping to find something wrong with it. Pulled off the rear cover, and the impellar is turning and everything seems OK.

So I'm going to go ahead and put on a known good pump - the one off the 305. - And I'll be sure to fill the block through the t-stat housing till full and top off the radiator, just to make sure there's no air. Hopefully it will circulate better than what it was before...

 

*crosses fingers, hoping to be the hero*

 

Well, after changing to another water pump and filling the engine through the top, it seems to be circulating nicely now. I let it run for around 20-25 minutes or so and temps stayed around the 170-180 mark, so I definatley think it will run cool now.

Adam - It may have been airbound as you said because I have the other pump on my workbench and I can't see anything wrong with it. MY HERO!! lol!

Now to the bad part. I have a leak from the pump gasket on the pass. side. So now I have to do this over again, because I couldn't drive it that way. That's only one bad thing. But there's a ton more circulation than there was before.

My other concern is that the engine is still smoking. Got a better look today, and yes, it's a bluish-white tint (oil I think). I don't have but about 30 actual driving miles since rebuilt, but I did go through the ring seating procedure by going WOT from 30 mph to 5000 rpm's and letting it pull back down to 30 and repeating 4 times. Still smokes.

Called the builder again...he says it may take up to a couple thousand miles before they'll seat. I've never heard of rings taking that long to seat....have any of you??

Since I'm finally off work for a couple days, I'm going to go ahead and fix the water pump leak and replace the intake gasket to be sure the intake isn't the cause for oil burning. If it continues to burn oil after that - then I think I'm down to the rings, or head gasket. Anything else I should look into for oil burning???

 

Depending on the type of rings he used it could take that long.

 

He used Enginetech moly rings, standard tension. Don't know if that helps..

 

the Chrome Molly could take that long, I believe.

 

I have about as much time on my 400 and it still smokes a bit at start up. I've been racing stock cars for years and every engine I rebuild will normally take one or two races on it before it doesn't do this. My advice would be to run it for a couple hundred miles and change the oil and make sure you don't have any metal in it and you should be fine.

I am pushing about 425-450hp out of mine haven't dyno'd just what it should run with what I have in it and mine ran hotter then I wanted so I ended up going with a Griffin radiator for mine. Makes a world of difference.

 

Since you've had the rear cover off the old pump, how deep are the impeller vanes in the casting?

Oil smoke can continue for a couple thousand miles or more on a freshly built engine. It's not abnormal, even with moly faced rings. The compression rings aren't intended to scrape the oil away anyhow - That's the job of the SS oil ring rails.

If the builder left a little more cross hatch in the finish hone process, the moly may have been chewed away before it temporarily "sealed" the rings/bores. If that were the case, you're basically going back to the old-school way of breaking in, via having to polish the bores a bit more before there is better oil control.

Don't lose a lot of sleep until you accumulate a few thousand and it's still smoking as much, or Favre retires. Juat keep clean mineral oil in it. Since you've cooked your oil fill, you may want to change it again now that the temperature is under control.

 

Thanks for the reassurance Vader and mykxt202! It has been a worry to me because I've rebuilt 4 engines before myself, but not this one. None had this problem. Rings set before I even drove it.

Already changed the oil, and reinstalled the water pump minus the leaks!

I was able to back the timing down a bit to around 20 degrees initial, but I still need to get a high torque starter. I was hoping it would be here by now!

I switched to a 160 degree thermostat in hope of keeping temp more under control. Runs at 220 max now, and idles OK, but lopey. Like you said Vader, I'll keep an eye on things for the first couple thousand miles and see what happens and hope it clears.

 

Since the last post, I put the high torque starter on, and it cranks like no tomorrow!! Funny how much it sounds like my old Dodge starter off my old Charger....

I now have my intial timing set at 24* initial, smoke is pretty much non-existant, idles better thanks to me finally discovering I have a "Idle Eze" adjustment on my carb! Runs much cooler too!

I think most of my problem was having the timing too retarded - making it run hot.

Now, it runs around 180-220 but no more!! This thing's a blast to romp on! I'll post a couple pics of it installed....

Thanks for the help!

 

Good to hear!!!

I think we all knew that with a little patience and a logical approach, you could get it sorted out. The right pieces are all there.

It is kind of amazing how much faster those other starters spin the motor than the Stone Age stupid Delco design starter. Now you see why I've been telling you since day 1 that you needed to do that. The weenie Delco starter keeps you from being able to run the timing where the engine wants it to be, and it's not the engine's fault the starter is too weenie.

Which kind of starter did you end up with..... the kind that has all round parts (Hitachi) or parts that are sort of squarish (Nippondenso)? All of the various mini-starters are either the one or the other.

Enjoy!!! Keep us posted as it breaks in and you get whatever other details remain taken care of. You ought to be just about jacked up like a mother now and ready to fo roast some Rustnags.

 

Thanks RB! Unfortunately, I still can't hammer on it like I want to due to the weak 10 bolt that's in it now. So far I've been getting away with punching it from a roll with no probs though. Looking around for a decent deal on a 12 bolt or 9"......

I got the starter by "trading".....I had the deep sump oil pan that wouldn't fit with my headers, so I talked the builder into swapping for this starter. Doesn't seem to be a quality one, but it wells very well!! Can't tell which kind it is really, but it has a small looking motor that bolts onto a aluminum block and the gear comes out the middle of it.

 

Congrats from Riley also. I wouldnt worry about that 10 bolt too much..Im running stickies and Ive been able to get on it more than a few times! And the best thing about them is....They are cheap and easy to replace!

 

Thanks Riley! How's yours doin?
Hit 12's yet?? Here's a couple of pics - Still trying to figure out a way to get my dual snorkle air cleaner to fit on it.......

 

One more (cheap chrome lol).....

 

That motor looks bad-***...Mine is awsome, I havent had it to the track yet due to a cracked windshield, Strip only car, running open headers...Im sure it will run at least 11's. Ive drove plenty of 12 sec cars. and this pulls A LOT harder. I'm having some back surgery done at the end of the month, so the track may have to wait till next summer. My wife wants to run the car....but you know..Id hate to see her get hurt or anything....Thats my excuse anyway!

 

Glad to hear it all worked out

If you can't get your HO air cleaner to fit, it would fit my car pretty well

 

Hey Confuzed...

Im just reading this post (a lil late) but heres my $.02 ...

Is your car a serpentine belt car? If so, theres a STRONG posibility that you had a STANDARD ROTATION water pump on your car when you needed a REVERSE ROTATION pump. I used to work at a PEP BOYS parts countder many moons ago and a lot of people would get the wrong pump. They would either...

- Not indicate that they had a serpentine belt.

- Get a box where someone did a "switch-a-roo" to save money. The standard pump cost way less than the serpentine pump.

- Tell us the wrong year/make/model/engine of their car.

- Or they didnt know that their car had an engine swap before they bought it. Say the car USED to have a REVERSED pump originally but now has a STANDARD pump. They ask for a pump, we give them a REVERSED pump. Get my drift?

Either way, im glad it worked out for you.

How's that G-Force treating you?

 

Pics show a v-belt...but great insight!

 

Ooops... Didnt notice that!

Maybe they gave him a serpentine belt pump??? I didnt notice that its an 83...

 

Jaydubb-

All I know is that it's a CAT hi-volume water pump, which has been residing on my work bench for a couple weeks now. I pulled the rear cover off, and everything looks fine. I don't get it either. I'm almost tempted to put the thing back on just to try it again!

As Riley said, I have a V-belt. But good idea anyway!!

I've heard of the reverse flow thing happening on serp. belt pumps. Makes me wonder though...does the pulley bolt up the same on serp. belt pumps and V-belt pumps? Reason I ask is, I can't see the impellar vanes direction with just the rear cover off.

Oh, BTW - the G-Force T-5 is treating me just fine so far!! Now if I can lose this one-legger 10 bolt rear that's in it now, I could stress test it from a stop with the 400!! Next year I guess.

I've already spent an absurd amount for this year on the car. Maybe I can get that 12 bolt Currie rear next year without the divorce! lol

 

Just swap in a posi unit!!!!! whats another 100.00-150.00. You can do it yourself you've come this far. Easy to do.

 

Well....you do have a valid point Riley. But I figure I've already upgraded the trans and all, and I'd like try and take it to the local strip here on "test and tune" days just for fun.

And I'll admit it - I don't have the experience at launching like you probably do, and I don't want to break it hopefully. That's kinda why I think I'd be better off just saving for a 12 bolt and maybe upgade the driveshaft somehow. Just Mo money!!

Of course, I doubt I'll touch the HP and TQ you're probably putting out since I (attempted) to build mine mainly for street use. I still regret not going roller though. It would idle better!!

If you seen my car, and the "primered" look my car's been "sportin" for the past two years, and the interior sucks too.....you'd think I was nuts for spending as much $$$ as I have already on it. Yeah - I've come this far, but I gotta long way to go!!

Boy - I talk too much! lol

 

That all makes sence, but at the track you are going to lose ALOT on your 60' times.
You should see my cars interior, you think yours looks bad.
here are some pics.