Head Gasket

[CUMMINS]

I have a LD-465-1 and I just blew the headgasket ,because I turned the pump all the way up, added a D turbo and was running 25' of timing, so I expected it ,but could I run a LDS gasket as a upgrade, and Is there a difference in the ld, ldt and lds blocks. I was under the impression that there wasn't until I read a thread about some block having the letters TD cast in them and they were stronger, does anyone have a ldt or lds motor with out the ''TD'' cast in.

 

[houdel]

I'm curious, where is the "TD" cast in the block. As for the head gaskets, there were plenty of problems initially with LDT/LDS head gaskets. I believe the original head gaskets had the fire ring as an integral part of the head gasket, those had problems so they went to head gaskets with separate fire rings and still had problems. Eventually they went to an improved head gasket with integral fire ring. That seemed to fix the problem, or at least correct it to a manageable level.

Possibly your engine had one of the earlier trouble prone gaskets, or maybe, as you suggest, you souped up the engine just a little too much, although your mods do not seem excessively radical. I'd suggest when you change your head gasket that you make sure you get the new, improved gasket with the integral fire ring.

Also, have you ever retorqued your head bolts? SOP requires retorquing the head bolts after then engine has been in service for a period of time (I forgot the recommended interval) as the head bolts DO stretch resulting in a loss of torque. There is a special tool required (not expensive) to torque the bolts under the rocker arm shafts, although I suspect you could torque those bolts without the tool if you wanted to pull the rocker arm shafts first.

Personally, I plan to retorque my head bolts on an annual basis just to minimize the likelyhood of a head gasket failure.

BTW, the leaky head gasket problem is the major reason that PS-28, page 9,
http://www.steelsoldiers.com/index.php?module=pagesetter&type=file&func=get&tid=1&fid=file&pid=38

REQUIRES you to crank the engine 2-3 seconds with the engine stop lever pulled out BEFORE starting the engine to check for hydrostatic lock!

 

[Recovry4x4]

Lee, here's an idea where that TD is on the block. I've not seen one without it. I'm told it indicates "Thick Deck"

 

[houdel]

Ken - Thanks, Lee

 

[cranetruck]

The timing, IMHO, probably was not the culprit here, my config is similar to yours. I did change the timing to 20 degrees, but did not turn up the fuel at all. My turbo is also a "D", non whistler.

Without turning the fuel up, I experienced a great increase in power, especially during acceleration, don't have to downshift so much in the hills and so on.
There is one little thing that is different between the N/A and turbo multies and that is the "smoke cam angle" inside the governor.
The cam angle effects the fuel delivery and I think it was changed to reduce the smoke along with the addition of the turbo (which was of course added to kill the smoke problem). The jury is still out on this one.
Bottom line is that without turning up the fuel, I can easily hit 11 to 12 psi turbo boost.

How much is "all the way" when you adjusted your fuel delivery? More than one turn?
What were you doing when the gasket blew, rpm, boost, load, highway, backyard?

You can help us prevent this kind of thing if we get the details and good luck with the rebuild.

Thanks,

 

[CUMMINS]

I turned the fuel up until I was out of threads on the screw,probly 10 or more turns, Egt never went over 1100, I was doing highway driving with some stop and go driving,I didn't notice the gasket when driving but when I got home it was spraying oil out the back of the head.Does your block have the TD cast in it, I got the heads off today and am waiting on the new style gasket , I had the old gasket with the individual fire rings, and it is supposed to be retorqued every 30 hours

 

[Squirt-Truck]

The new and improved head gasket has separate fire rings. The difference is in the vent channel around the fire ring. It allows any oil or coolant to NOT enter the cylinder and blow the gasket, it also pervents a blown ring from taking out the adajacent cylinder. At least this is what Continental, who redesigned the gasket, says it is for. I just replace mine and they sent me the detail to illustrate the differences. OR..does the LDS use a different gasket? Let me know an I can try to scan the documenht and send it to you.

 

[houdel]

Squirt-Truck - I hate to disagree with you, but I believe the newer and more improved head gasket now has the integral fire rings. Can anyone out there with intimate knowledge of this subject settle the fire ring issue once and for all?

 

[CUMMINS]

I talked to the people at memphis equipment and they told me that all the multifuels could use the new gasket and that the fire rings were built in the new gasket ,but this is the first time I have messed with multifuel so I don't know.

 

[red devils dude]

Squirt-Truck - I hate to disagree with you, but I believe the newer and more improved head gasket now has the integral fire rings. Can anyone out there with intimate knowledge of this subject settle the fire ring issue once and for all?

houdel is right I have the new gasket on hand, integral fire rings
with red sealant.

 

[Westech]

Hey BJ, when I turned up my pump just a little I have to watch that pyro alot! if I give her it will shoot right to 1000* and thats after turbo. Would reseting the timing to 20* help with the exhaust temps? or make it worse?

 

[mangus580]

retarding the timing will increase the temps

Hence the reason I think I am going to move mine back up.

 

[cranetruck]

Mike, the engine IP has an automatic advance of 8 degrees. If you run your turbo charged engine with injection beginning at 25 BTDC, you may experience pre-ignition and loss of power.
As far as "turning the fuel up", it sets the maximum fuel delivery, it's still under the control of the operator by how hard he steps on the "gas" pedal. You can have the fuel up all the way and still be safe, I'm sure.

 

[m35a2cowner]

Retorque heads

Does anyone know the interval at which you retorque the head bolts. Also hot or cold? Thanks

 

[jwaller]

I had the old gasket with the individual fire rings, and it is supposed to be retorqued every 30 hours

 

[Westech]

the TM for the head gaskets says "if leaking head bolts should be retorqued on a cold engine" does not saty anything about every 30 hours

 

[CUMMINS]

I just got the truck back together and running, but I need to know if I need to retorque the heads when hot, I followed an instruction sheet that came with the gasket set and torqued the heads to 157 ftlb, but it says not to retorque the gasket on a hot engine,however in the Memphis Equipment multifuel manual it says to torque the head to 130 ftlb and retorque when hot ,Which one is right

 

[AMGeneral]

My deuce has a LDT-465-1C multifuel in which I replaced the rear head (blew the injector out of the head!)and both head gaskets with the new design gaskets and it still blew the front head gasket right behind the fan.No water leaks,No oil leaks,just compression.

 

[houdel]

I'd strongly suggest anyone doing any sort of work which involves removing the head - be it to replace a gasket, valve job or whatever - have the heads surface ground before replacing them. Just a minimal amount, we are not going for a compression increase here, but just to make sure the bottom of the head is perfectly flat.

Cast iron does warp over time, especially with all the heat and pressure a cylinder head is subjected to. Having it surface ground before reinstalling will assure the bottom of the head is perfectly flat so that new head gasket can do its best job of sealing to the deck. No amount of torquing is going to help much if the cylinder head has warped, as they often do!

 

[devilman96]