why are my heads lifting
why are my heads lifting Well I went to the track last week for my first race of the season and it seems that my coolant is transfering from the radiator to the overflow tank only when under hard acceleration. It may be burning some as well. I have noticed the overflow tank level go up but not as much as the amount of coolant I had to refill the radiator with. I had to add a total of 1 gallon to make 4 passes. No leaks and no water in the oil. When this started I was not even using the nitrous. I ran all last year with no issues and have been hot roding around on the street this year just fine. On motor I am only making 561 rwhp and the most I have ever sprayed is a 125 shot on a safe tune. I have stock size ARP head studs, Darton MID sleeved ls6 block 4.127 bore, TEA TFS 245's and cometic .040 x 4.125 MLS gaskets (dry) for darton sleeves, .042 quench, 11.9 scr, 250's cam, 4500 ft elevation, 91 in tank, race fuel in stand alone, 29 degrees total timing -7 on the spray, BR7 plugs, evens waterless coolant and edelbrock water pump. There have never been any signs of detonation either. I retorqued my heads once right after I built the engine last year (70 lb's w moly) and the block was freshly resurfaced when ERL did the sleeves. The heads were brand new as well. Is there anything that could cause this that I am missing?
Ya I think it is leaking through the head gasket, I just dont know why it is at my power level. There are no signs of coolant leaking anywhere. It runs nice and cool and I can drive it all day without a problem if I dont drive it like im at the track. (the whole point of building the car in the first place) I bought the block from ERL at a discount because another customer had not payed his bill. I asked them before they sent it to me if it would be a good idea to have 1/2" studs intalled and they said I wouldn't need them unless I planed on spraying 300 or more. I would just like to be able to pin point why I am having this issue in the first place before I tear the whole thing down and spend $1000 plus for head gaskets, 1/2" studs, resurface block / heads, and two 350 mile round trips to the machine shop to drop it off and pick it back up. Eghhh! ya hear about it but ya never think it will happen to you.
no signs of detonation. 29 degrees total timing and 7 degrees retarded with nitrous on a #57 jet. I am gona try loosening the head nuts one at a time and retorquing them again this weekend and see if any of them move. Only thing that crosses my mind is the main fuel rail pressure droping and leaning it out but I doubt thats the case. Plugs look good but they are not fresh plugs and I didn't even look at them until I drove it 9 miles back home so who knows. No detonation marks though.
Is this a fresh engine or recently drained the cooling system? If so it may be simply you don't have enough coolant in the engine and as you run it the level goes down from the source. BTW when you have an overflow bottle, you fill that and NOT the radiator. If you have a leak you would surely notice a gallon missing either in the exhaust, oil, or on the ground.
Worth mentioning ARP head stud torque is 80 ftlbs
Worth mentioning ARP head stud torque is 80 ftlbs
Ya good point. I noticed ARP revised there torque specs since I built the engine and thats what I will torque them to this time. I would still of thought it would be ok since 70 was the spec since the ls1 was invented up until recently. I built this engine about a year and a half ago and I havn't touched the cooling system since. It has evans coolant in it that is suppose to last forever. There is no leak or water in the oil. I thought I smelled a hint of coolant in the exhaust once but im not sure. It only does it at wide open throttle under a load though. There is no smoke or smell coming from it at idle or reved up in neutal. Of course I didn't rev it up to 6-7 thousand rpm's for 10 seconds straight either. After I made a pass I noticed smoke in the overflow tank when I removed the cap. I am assuming it is combustion gasses being forced into the cooling system past the head gasket. I have observed the level in the coolant tank going up some but it hasn't overflowed and I havn't drained any out of it. When I first discovered the problem I was in the staging lane to make my second pass and my engine temp started getting hot. I took it back to the pits and found the radiator low and the overflow a little over full. Then after every pass I would need to add at least a 1/2 quart of coolant to the radiator to top it off. I appreciate any ideas I can get.
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Pull the heads, do it again. Do to the recommended limits, I do not have the spec handy but I am sure easy to find. If your still having issues, thicker studs, or moving to a different block (extreme).
It sucks but maybe what is needed. Keep us posted.
It sucks but maybe what is needed. Keep us posted.
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How do you know its not knocking a little ?
Might just have gotten a bad gasket?
you really dont need 1/2 studs but if the gasket and block check out good got some super bad news When did you order or buy the tfs 245 are they the 6 bolt casting ? have the heads checked for cracks if you bought the heads used there a small run of bad casting from 2007 i think.
Might just have gotten a bad gasket?
you really dont need 1/2 studs but if the gasket and block check out good got some super bad news When did you order or buy the tfs 245 are they the 6 bolt casting ? have the heads checked for cracks if you bought the heads used there a small run of bad casting from 2007 i think.
I havn't loged anything but there has been no audible knock or detonation marks on the plugs. I bought the heads from TEA in february 2010. I installed the gaskets dry but Ive heard from a lot of people on this forum to put copper coat on them even though cometic says not to. Anyone heard the latest take on doing that?
A leak down tell you anything???
" Only thing that crosses my mind is the main fuel rail pressure droping and leaning it out but I doubt thats the case."
If you don't log the runs, how can you be sure it's not lean?? [Especially, considering the above comment.]
" Only thing that crosses my mind is the main fuel rail pressure droping and leaning it out but I doubt thats the case."
If you don't log the runs, how can you be sure it's not lean?? [Especially, considering the above comment.]
I'm not 100% sure its not going lean, but by the looks of the plugs they did not look too lean and had no signs of detonation, melting, or aluminum on them. Tan in color. The main reason for me keeping this thing as conservative as it is was to not have to babysit the tune or wory about problems like this. I guess thats part of racing.
Last edited by dtroike; May 31, 2012 at 04:58 PM.
