Car Forums  

Go Back   Car Forums > Technical Discussions > Repairs & Maintenance
FAQ Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-13-2006, 08:03 PM   #1
Icarus6
CF Newbie
 
Join Date: Nov 2005
Posts: 19
Musical Heads

Hello again, Guys and Gals...

I've been struggling with this one for a while, and it just crossed my mind to slap it on here and see what other's think.

A couple of years ago, I bought a full sized 1981 Chevrolet Blazer (K5). The truck was originally had a 305 SB, but was sold to me with a remanufactured 350 SB. The 350 had blown head gaskets and was sucking coolant into the cylinders. The cylinders were badly washed out and damaged.

I decided that I liked the truck enough to make it a project. So I bought a 400 CSB, had it machined and built with all performance parts built for low end torque. Too many parts to list...al brand new. The heads were the heads that came on the 400 (which had never been dissasembled and machined before). New 4 row radiator, stainless steel flex fan, new hoses, starter, wires, distributor, the whole nine yards.

The truck ran great and ate anything ahead of it without so much as a flinch for about 3 months. About this time, it started overheating and burning coolant. I brought the vehicle back to the machine shop that built the engine...and was told the head gaskets blew. They planed the heads and re-installed the heads. All seemed well.

3 months later...same thing. Overheating and burning coolant. This time I brought it to someone else. They told me that I had a blown head gaskets again. They also stated that the vent holes coming up through the block were filled with crud...a creasote looking sh*t. They drilled out the vent holes, flushed the coolant system, planed the heads, replaced gaskets, and re-installed the heads. All seemed well.

3 months later...same thing. Overheating and burning coolant. Took it back to the same guy who changed the head gaskets and drilled out the vent holes. Same scenario, blown head gaskets and plugged vent holes. By now the heads had been planed enough times. So I got another set of heads, planed and 3 way valve job. Had the vent holes drilled out again, coolant system flushed again, new heads put on with new gaskets. All seemed well.

This time I immediately started burning coolant and overheating. Cracked heads...yay! Magna flux doesn't catch litle itty bitty internal cracks...oh well.

I'm about to try one more set of heads, coming from a properly running vehicle. This time I want to, additionally, try a different set of head bolts and a high flow coolant pump. Of course, because I'm going to use 350 heads, vent holes will need to be drilled. You may ask...why 350 heads...? Because they're inexpensively available to me and I'm reaching the end of my rope with these issues...this is a last ditched effort to revive the thing before I dump it.

I'm curious what other people have to say about this set of circumstances. Why do I keep blowing gaskets? Why do I keep building creasote in the block vent holes? I don't beat the truck...I drive it, but not destructively.

By the way, in case someone's curious from a stress perspective...the truck is stock suspension.

Any tips, tricks, and previous similar experiences would be helpful.

Thanks,

Icarus
Icarus6 is offline   Reply With Quote
Old 01-14-2006, 06:55 AM   #2
82Chevy
CF Newbie
 
Join Date: Jan 2006
Location: Everett,WA
Posts: 12
is this an automatic or manual transmission and what type of driving are you doing? (4 wheeling or just regular driving)
82Chevy is offline   Reply With Quote
Old 01-15-2006, 10:55 PM   #3
cargrime
CF Newbie
 
Join Date: Jan 2006
Posts: 34
Need more info

icarus6

I've been there with my v6 chev.

I need to know if both head gaskets blew or was it just on one side of the engine and if it can be narrowed down - what cylinder took water? .Did you pull a plug wire while the engine was running to pinpoint the affected cylinder?

This is the first thing you do in a head gasket failure - find the cylinder that is not firing(taking water) Then when you get the heads off take a magnify glass and find out exactly where the leak was on the gasket itself. If you don't pinpoint it then it's all just a guess. At first it sounded like cracked exhaust seats on the head but then you say you tries another 400 head and got the same problem. Chances are your problem is block related. When the head gasket fails you got a 50/50 chance that the block needs resurfacing

Now I did not clue into this until the 3rd head gasket replacement on my v6 chev forced me to do some heavy rethinking of the problem.

Most shops will just want to do the heads because they can make a quick buck by doing the heads they don't really want to do the block unless you do all the dirty work yourself or be willing to pay them about 5 grand.

The gunk you speak of I don't know but I do know that a head gasket leak will get co2 and oxygen gas into the coolant and this will accelerate rusting. This might react with ethylene glycol and create some kind of goo.

Another question: did you use antifreeze (prestone or similar) during these problems?

did you blow any freeze(frost) plugs during this time?

Last edited by cargrime : 01-16-2006 at 01:17 AM.
cargrime is offline   Reply With Quote
Old 01-16-2006, 01:44 PM   #4
Icarus6
CF Newbie
 
Join Date: Nov 2005
Posts: 19
82Chevy....

This is an automatic transmission, 4wd, 3.70 gears. Mostly ~normal~ driving...with occasional offroad adventures.

Cargrime...

It's difficult to remember, partly because I had most of the work done by someone else...and because the has been going on for a while (so it's been a while since I saw it). But, if my memeory serves me, each time the drivers side head gasket blew and the cylinder closest to the firewall took water.

The antifreeze used was good antifreeze (I believe it was prestone)..and it was properly mixed 50/50. I'm not sure what a "frost plug" is.

I realized the potential that the block deck needed resurfacing. I suppose I'm in a bit of denial...because I don't want to pull the block. I was hoping that I may have managed to overlook something simple.

Thanks

Icarus76
Icarus6 is offline   Reply With Quote
Old 01-16-2006, 10:07 PM   #5
cargrime
CF Newbie
 
Join Date: Jan 2006
Posts: 34
more about the heads

icarus6 you say

quote
"This time I immediately started burning coolant and overheating. Cracked heads...yay! Magna flux doesn't catch litle itty bitty internal cracks...oh well"
end quote

If I understand this right these were a totally different set of heads. I don't know why you concluded that it was cracked heads a magna flux is quite good at finding cracks. It all makes sense though. Every time you installed the head gasket there was a tiny head gasket leak beacuse of an eroded spot on the block surface. It does not show up right away but gets progressively.
worse.
The block surface in the area of the leak get eroded.(or a 50/50 chance the head will get eroded) Also the head gasket can get eroded as well
Remember there is a wacK of co2 and oxygen present in the cylinder gases and combined with water causes the erosion. In your case it looks as if the block surface around a particular cylinder is eroded. The last time you installed the different set of heads it lead to an immediate failure. The block surface must be eroded so bad that new heads/gaskets don't make any difference.

This block erosion on my v6 showed up in a partial circle of about 60 degrees around, on the number one cylinder area of the block surface.

Last edited by cargrime : 01-16-2006 at 10:14 PM.
cargrime is offline   Reply With Quote
Old 01-18-2006, 01:40 PM   #6
Icarus6
CF Newbie
 
Join Date: Nov 2005
Posts: 19
There have been 4 head resurfaces and gasket changes, spanning 3 different sets of heads (not including the initial installation and the change I propose to perform now). The second set of heads were the ones that I refered to as being cracked, for 2 reasons.

After immediately overheating and burning coolant, these heads were removed. There was no evident breach in the head gasket (I saw this myself..examinined it for some time). The mechanic I'm working with on this also stated that he believed the heads must have been cracked...despite having been magnafluxed. Therefore I take away 2 pieces of information...they were cracked...and mangaflux didn't catch it.

Reportedly, the block has been inspected for block deck imperfections during previous head and gasket changes, with none found. I understand your reasoning, and will look again...myself.

In my original message, I mentioned a couple additional initiatives...changing the head bolts and changing the water pump to a "high flow" model. Is it possible that head bolts stretched...so that proper torque is not translating to the proper compressive force? Is is possible, for a "high" performance engine with a "high" volume radiator, that a "high" flow water pump would be required. I'm wondering if inadequate flow is a contributor to this crud phenomenon.

I hate to even say it...but I'm aslo wondering about a sealer. If I put a sealer in the coolant loop immediately after a gasket change...would that take care of any small imperfections in the block / gasket mate? What are the cons...I imaging there must be some.

Thanks,

Icarus
Icarus6 is offline   Reply With Quote
Old 01-18-2006, 10:51 PM   #7
Wally
I Know More Than You
 
Wally's Avatar
 
Join Date: May 2004
Location: Oz
Posts: 2,564
So if I read correctly, you have blown gaskets on two motors. The second motor you have had the problem four times?

So what do the motors have in common? Answer = you.

Sludge?. Well it is generally caused by a cold engine. What happens is that gases from combustion find there way into the sump. Where there are cold spots the gas condenses into an acid. The acid combines with the oil and deposits in the galleries (if the oil isn't changed at appropriate intervals).

The other cause of sludge is a coking effect from the heads getting too hot from lack of coolant or insufficient oil flow.

So you need to look at how regular you oil/filter changes have been, whether you are using the correct grade oil, the correct coolant, the correct thermostat, etc.
__________________
"She gave me a look only a mother could give a child."
Wally is offline   Reply With Quote
Old 01-18-2006, 11:39 PM   #8
cargrime
CF Newbie
 
Join Date: Jan 2006
Posts: 34
about the crud in the heads

Wally

Good input - but I think Icarus6 means that the water passages in the heads were filled with a hardened crud. He was not refering to the oil galleries as there are no oil galleries in the head. The only oil that gets into the head is via the hydraulic lifter pushrod.



This is what Icarus means when he says
quote
"They also stated that the vent holes coming up through the block were filled with crud...a creasote looking sh*t."
end quote


Icarus6 also says
quote
"In my original message, I mentioned a couple additional initiatives...changing the head bolts and changing the water pump to a "high flow" model. Is it possible that head bolts stretched...so that proper torque is not translating to the proper compressive force? Is is possible, for a "high" performance engine with a "high" volume radiator, that a "high" flow water pump would be required. I'm wondering if inadequate flow is a contributor to this crud phenomenon"
end quote

I've been there as well, and broken many a head bolt trying to coax some additional force out of the bolt to seal a head gasket leak. It never worked though and cuased more damage than if had not touched it.

Evidently the head bolts have some natural stretch to them and I suppose the higher quality bolt will allow more stretch before it breaks. I don't believe a head bolt will have a stretch that acumulates with time.

The high flow water pump probably would not hurt but I don't think you'll see any better cooling with the water thermostat left in. Even when a thermostat wide when open has a considerable restriction to the flow of water. Besides, extra cooling is only required in the summer months. If you want the ultimate system then get a custom made diverter valve that will bypass the water thermostat . So in winter time flip the valve and everything is stock(thermostat in ) and in the summer time flip the valve the other way and the thermostat is totally bypassed. This alone will create more flow through the rad without the extra cost of a high flow pump. I run without a thermostat in summer and run at least 20F. degress cooler

i don't think that a higher flow of water will solve the crud problem. I still think this was a reaction with the antifreeze as I have some proof of that

Last edited by cargrime : 01-19-2006 at 01:46 AM.
cargrime is offline   Reply With Quote
Old 01-18-2006, 11:47 PM   #9
Wally
I Know More Than You
 
Wally's Avatar
 
Join Date: May 2004
Location: Oz
Posts: 2,564
My apologies, I thought he was talking about the oil returns in the valley.

If its treacle in the water ways, it's probably some sort of mastic? Maybe someone has been using gasket sealer on the heads and not retorquing after the first engine warmup?
__________________
"She gave me a look only a mother could give a child."
Wally is offline   Reply With Quote
Old 01-19-2006, 12:46 AM   #10
vwhobo
CF's Anal Orifice
 
vwhobo's Avatar
 
Join Date: Feb 2003
Location: Redneck Hell
Posts: 8,630
Do you subscribe to a newsletter that has stupid things to say on a forum? It sure seems like it.

Quote:
Originally Posted by cargrime
I've been there as well, and broken many a head bolt trying to coax some additional force out of the bolt to seal a head gasket leak. It never worked though and cuased more damage than if had not touched it.
Over torquing a bolt to seal a leak. That's a genius move if ever there was one. Do you think the manufacturer has a specified torque for the fastener for a reason? Not only do you take the chance of breaking the bolt, you also in all probability distort the head and block which will actually make the leak worse.

Quote:
Originally Posted by cargrime
Evidently the head bolts have some natural stretch to them and I suppose the higher quality bolt will allow more stretch before it breaks. I don't believe a head bolt will have a strecth that acumulates with time.
No kidding, it's called elasticity. All bolts stretch when torqued. As a matter of fact, using a torque wrench is nothing more than a simple way to determine how much stretch, and therefore clamping force, the fastener is applying. If you don't believe a fastener takes on a set stretch after time, perhaps you should confer with the manufactures again to find out how wrong you are once again.

Quote:
Originally Posted by cargrime
The high flow water pump probably would not hurt but I don't think you'll see any better cooling with the water thermostat left in. Even when a thermostat wide when open has a considerable restriction to the flow of water. Besides, extra cooling is only required in the summer months. So in winter time flip the valve and everything is stock(thermostat in ) and in the summer time flip the valve the other way and the thermostat is totally bypassed. This alone will create more flow through the rad without the extra cost of a high flow pump. I run without a thermostat in summer and run at least 20F. degress cooler
More pure f*cking genius. The thermostat is in place for a reason dummy... To regulate the minimum temperature of the coolant. Removing it at best causes the engine to take longer to reach optimum operating temperature, which causes additional wear. At worst the coolant flow is not properly restricted and therefore can easily cavitate in the heads and block causing hot spots and serious damage. Do you think there's a reason that even racing engines that don't use a thermostat still use a flow restrictor just for this purpose?

A great man once said that it's better to remain silent and appear ignorant than to open your mouth and remove all doubt. You seem to go out of your way to remove all doubt at every opportunity. You may think you're helping, but you're not. You may also think that your "advice" is helpful, but it is not. If you truly want to help people then the first step would be to shut up. You'll learn more by listening than you will by talking, something that someone should have slapped into your head at the age of about three. Please do not waste bandwidth with your drivel anymore. I'm sure you're a very nice person and your intentions are good, but your information sucks. Do us all a favor and stop typing.
__________________
Thanks for the pic, jedimario.

"Everybody believes in something and everybody, by virtue of the fact that they believe in something, use that something to support their own existence."
Frank Vincent Zappa, 1940-1993

vwhobo is offline   Reply With Quote
Old 01-19-2006, 01:31 AM   #11
cargrime
CF Newbie
 
Join Date: Jan 2006
Posts: 34
more loose ends

vw hoho said

quote
"At worst the coolant flow is not properly restricted and therefore can easily cavitate in the heads and block causing hot spots and serious damage"
end quote

Now you have really proven how much you know. This statement is so wrong and misleading that I can barely restrain myself.

I did a quick google search and found this site http://www.joesfalcon.com/sped3/elecfan.html


where I quote a paragraph from that site.

quote
"All these modifications have plusses and minuses and can either help the problem or make it worse depending on what is causing the overheating. For example, you can move the coolant through the radiator so fast that it doesn't have the time to cool as it pass through, particularly in low airflow conditions such as at idle. Since the coolant never cools completely, quite hot coolant re-enters the engine, the heat of the engine is added to it so it is now hotter than the first time, only the same amount of heat is extracted from the coolant as it passes through the radiator again so now the coolant is even hotter as it re-enters the engine. Inside the engine more heat is added to it and so on"
end quote

Now VW hobo i'm suprised that you did not post this first to back up your argument, but you may use the above quote if you wish.

The above quote is so so so wrong and misleading that I want to throw up.
I have a math and physics background and the above example is only one of thousands of incorrect and misleading information on the internet. You rarely find the correct version on the net and my approach is take the internet with some caution. My approach is based not only on what I know but what the math and physics say This results in a very unbiased approach that has it's only proof in the mathematical or physical reality.

But why is it that on my chevy v6 I can wave to other motorist as they are parked on the side of the road from overheating while my engine purrs at 180F on a super hot day??
Well I don't run a therostat in the summer. It extends the life of my engine and I never get cavitation of hot spots in the head.


vw hobo said
quote
If you don't believe a fastener takes on a set stretch after time, perhaps you should confer with the manufactures again to find out how wrong you are once again. "
end quote

There is some permanent stretch but it does not accumulate with time Further this permanent stretch is far smaller that the stretch due to the elastic stretch- that is, as the bolt is loosened this elastic stretch will reduce to zero leaving the permanent stretch On the other hand if the permanent stretch is greater than the elastic stretch then the head bolt is of poor alloy and will break I don't think you'll ever find this condition in a head bolt unless it is over-torqued.
Now if the permanent stretch accumulated with time then we'd have millions of cars on the side of the road with blown head bolts.

Last edited by cargrime : 01-19-2006 at 01:49 AM.
cargrime is offline   Reply With Quote
Old 01-19-2006, 01:36 AM   #12
Wally
I Know More Than You
 
Wally's Avatar
 
Join Date: May 2004
Location: Oz
Posts: 2,564


cargrime I bet you wish you hadn't added that large addendum to your original post after I posted.
__________________
"She gave me a look only a mother could give a child."
Wally is offline   Reply With Quote
Old 01-19-2006, 01:44 AM   #13
cargrime
CF Newbie
 
Join Date: Jan 2006
Posts: 34
well

wally

no regrets
cargrime is offline   Reply With Quote
Old 01-19-2006, 01:44 AM   #14
Wally
I Know More Than You
 
Wally's Avatar
 
Join Date: May 2004
Location: Oz
Posts: 2,564
Quote:
"All these modifications have plusses and minuses and can either help the problem or make it worse depending on what is causing the overheating. For example, you can move the coolant through the radiator so fast that it doesn't have the time to cool as it pass through, particularly in low airflow conditions such as at idle. Since the coolant never cools completely, quite hot coolant re-enters the engine, the heat of the engine is added to it so it is now hotter than the first time, only the same amount of heat is extracted from the coolant as it passes through the radiator again so now the coolant is even hotter as it re-enters the engine. Inside the engine more heat is added to it and so on"


What a load of drivel. Once at it's sensible heat limit, the coil will have a finite heat rejection capacity. Moving the water through faster will result in a lower temp difference, but because the flow is increasing through the head the temperature difference will also be lower, so the net result is the radiator entering water temperature will be lower.

watts = 4.19 x l/s x TDC
__________________
"She gave me a look only a mother could give a child."

Last edited by Wally : 01-19-2006 at 01:47 AM.
Wally is offline   Reply With Quote
Old 01-19-2006, 01:52 AM   #15
vwhobo
CF's Anal Orifice
 
vwhobo's Avatar
 
Join Date: Feb 2003
Location: Redneck Hell
Posts: 8,630
Quote:
Originally Posted by cargrime
Blah, blah, blah. More blathering bullshit.
The reasons that I didn't use that "information" is because;

a. It does nothing to support my arguement.

b. It is so incorrect I can only assume that that site is written by you.

You may have a math and phsics background, but I have the automotive background, not to mention years building just about every type of engine you can imagine. The information I provided about cavitation and hot spots is irrefutable by someone with even a small amount of automotive knowledge... Perhaps that's why you refuted it. If you truly had a background in physics, the fact that a bolt stretches every time its torqued AND takes a set after time and use would not have been a mystery to you. So since you are so all knowing, I'll give a chance to either shut up or redeem yourself. Why is it that all sorts of racing engines use a flow restrictor instead of a thermostat? (Hint: The answer is a few posts up). And if you have no thermostat in your van, what exactly is it that regulates your minimum temperature to 180 degrees? I'll be waiting professor.
__________________
Thanks for the pic, jedimario.

"Everybody believes in something and everybody, by virtue of the fact that they believe in something, use that something to support their own existence."
Frank Vincent Zappa, 1940-1993

vwhobo is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Forum Jump



All times are GMT +1. The time now is 03:50 PM.

Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2002 - 2011 Car Forums. All rights reserved.