"Fixing" the Lotus head

[CanadianDaytona]

I recently acuired a sweet Daytona Iroc RT.
The head is Mint, and I'd like to keep it that way.
I've heared there is some welding that needs to be done to streagthen these heads, but am having a hell of a time finding out what that involves (I know about welding up the plugs between the spark plugs but nothing else)

Anybod got some Info on this...maybe even a Nice write up with pics that I'm missing.

Thanks
Chris

[Turbodave]

I wouldn't worry about welding it if it's not leaking. The welding is done on the core plugs that are on top of the head. Many times what happens is that the original steel plugs cool slower than the aluminum head them and it results in cracking of the head and a coolant leak in that area. The factory fix was to install aluminum plugs, but on a head that's already cracked welding is the only fix.

[CanadianDaytona]

And thats the only problem area? The plugs already look to be aluminum.

[Turbodave]

If it's already got the aluminum plugs in it and it's not leaking I would just let it be.

I do recall people welding up a hole in the bottom of the head where a plugged oil passage sometimes leaks from, but I don't have any personal experience with this.

[turbovanman²]

If you still have the steel plugs, remove them and put aluminium ones in, FWD Performance carries them.

Also, when you remove the head, there are 3 cup type plugs used for coolant and oil, some say with time, they start to leak so mine are getting screwed in plugs then machined flat.

[CanadianDaytona]

Like on the Hybrids...

[turbovanman²]

Like on the Hybrids...

Yeppers.

[Directconnection]

If you still have the steel plugs, remove them and put aluminium ones in, FWD Performance carries them.

Simon...I disagree. I used to be on the RT Mailing list for years and this type of thread always came up bi-weekly. Alot of people thought the steel plugs always meant your head was cracked or will soon be. Not the case. Alot of people chimed in reporting that their 150,000+ mile R/T with it's original head still had steel plugs and no problems. And some people had aluminum plugs in the newer casted replacement heads and those still cracked. Sopme speculated the torque used at the factory...

2 of my 3 r/t's have steel plugs and no cracks (but oil pump is another story...)

If it isn't weeping or cracked, don't even look at them crosseyed!

[turbovanman²]

Simon...I disagree. I used to be on the RT Mailing list for years and this type of thread always came up bi-weekly. Alot of people thought the steel plugs always meant your head was cracked or will soon be. Not the case. Alot of people chimed in reporting that their 150,000+ mile R/T with it's original head still had steel plugs and no problems. And some people had aluminum plugs in the newer casted replacement heads and those still cracked. Sopme speculated the torque used at the factory...

2 of my 3 r/t's have steel plugs and no cracks (but oil pump is another story...)

If it isn't weeping or cracked, don't even look at them crosseyed!

Interesting. Personally, I would run aluminum, that way, it has the same expansion characteristics,

I have 4 heads with steel plugs and 4 cracked heads.

Oh, and make sure there not too tight.

[Directconnection]

I have 2 heads here as well... one steel one aluminum plugs. The aluminum plugged head is cracked.

[86Shelby]

I agree with Steve. Don't fix what isn't broken. The single steel plug my machinist removed nearly damaged the head severely. It simply wouldn't come loose and ended up stripping the threads and busted out a chunk of the head when it finally did come out. The other two plugs are still steel because of that.

[CanadianDaytona]

Ya I'm noticing the Aluminum Plugs are being a biotch to come out...Stopped trying because I didn't want to bust one.
Okay So possibly do nothing to head..What about well its out..back cut valves or any other relitivle cheap mods

BTW what its the deal with the oil pump/intermediate shaft..why so prone to fail on the RT's..aren't they the same as the TII ones?

[turbovanman²]

BTW what its the deal with the oil pump/intermediate shaft..why so prone to fail on the RT's..aren't they the same as the TII ones?

On a TIII, they spin faster than a regular 8 valve, and the shaft did have a different part number but physically, there the same. Also, its said that due to the tighter timing belt or maybe even looser, it takes out the front bearing.

[Turbo3Iroc]

There's alos a lot more valve spring tension on these motors so that coupled with the faster spinning I shaft puts a lot more stress on it. They also weren't hardned from the factory making them weaker. I've also heard the harmonics from a slightly loose belt can do an I shaft in.

Also I agree it's best to leave them alone until something happens. Don't try to take them out, just leave them be because the torque rating from the factory is super high.

[Directconnection]

The intemediate shaft was heat treated from the factory, just not above and beyond what it really needs from what I have heard over the years. The TSB pump and shaft kit is supposed to be hardened to a much higher rockwell rating. But, those are VERY hard to find (I got one here from years ago when available) But others have had success with what.... stock int. shaft and a MP pump of sorts was it?

[2.216VTurbo]

I've done my own non-scientific study of our belt-harmonics-causing-valvetrain-nightmares, you know, pretty much drinking beer and staring at the motor on the stand kind of stuff My idea (which I have not bothered to implement yet(if ever now that I'll be swapping for that 'other' 16V motor without valvetrain issues for my Rampage ) )is to add another idler pully on the long side span for the timing belt. I gotta think its the tension/laxity repeated cycling from the spring tension that is a major contributor to the belt shearing/I shaft destruction in our TIII's. I think another pulley would dampen the 'pulses' of the belt harmonics

[turbovanman²]

Thats a great idea Alan, I might mess with that when putting mine together as I need to play around with pulley's and such due to the larger int shaft pulley I need to use.

[Turbo3Iroc]

That's what I get for posting half asleep Steve lol.

Alan, adding that additional idler could help but I also believe that it is the sharp turn at the crank that also contributes to short belt life. Adding an additional idler though it would reduce the harmonics on the long side, it would also make that bend sharper. Just something to think about.

Kelly

[Pat]

Here's my I shaft/Oil pump/Bearing theory

http://www.turbo-mopar.com/forums/sh...919#post117919

On whether or not to swap out the steel core plugs, if it hasn't cracked yet after 14+ years and however many miles it's gone, it probably is not going to. I have few with steel plugs that are fine that I've left alone for years of beatings with no issues.

[Directconnection]

Pat...that was my theory as well a few years back. It wasn't until I pulled the pan and intermediate shaft out of my '90 VNT car that had the same failure did I wonder if it's totally to blame. The factory original 145k bearings were still good. So, I installed a new mellings and a good used shaft and ran it for another 10k without any issue.


I accidently over-revved that engine 2 times going from 3rd back into second instead of 4th (I had a bad cable that didn't help matters) to around 8k+ which may have caused the problem down the road.


I have noticed most of the T-I engines I pulled apart had flaking int. bearings as well. I was shocked to see good bearings on my car.