4-Cyl. Exhaust Manifolds (LEW request)
Discussion
Guys,
I'm after some information regarding the many cracked exhaust manifolds on 4 cylinder Esprits.
If you've had yours replace. Please email me at kato@lotusespritworld.com with the following information (if you have it).
1. Model & Mileage
2. Year of replacement
3. Who did the repair/fitting
4. Part No. of Manifold fitted
Thanks in advance for your replies.
kato
Lotus Esprit World
I'm after some information regarding the many cracked exhaust manifolds on 4 cylinder Esprits.
If you've had yours replace. Please email me at kato@lotusespritworld.com with the following information (if you have it).
1. Model & Mileage
2. Year of replacement
3. Who did the repair/fitting
4. Part No. of Manifold fitted
Thanks in advance for your replies.
kato
Lotus Esprit World
Hi,i got replaced mine at April this year.I got an 92'SE with 20000 miles on the clock.
I've bought the new exhaust manifold at eBay(brand new,original part)for the half price.
My friend is a mechanic and works only on exotic cars.
He needs only 10 hours.He`s removed the manifold very simply from underneath the car.
I paid for the manifold 655 Euro,about 700 Euro for bolts,gaskets(no joke) and another 700 Euro for the whole job.
I must say that the quality of these cast iron pieces is bull*****!If you buy a new one there is some work to do on this part.
And that you have to remove the whole engine is a good fairy tale. :-)
I've bought the new exhaust manifold at eBay(brand new,original part)for the half price.
My friend is a mechanic and works only on exotic cars.
He needs only 10 hours.He`s removed the manifold very simply from underneath the car.
I paid for the manifold 655 Euro,about 700 Euro for bolts,gaskets(no joke) and another 700 Euro for the whole job.
I must say that the quality of these cast iron pieces is bull*****!If you buy a new one there is some work to do on this part.
And that you have to remove the whole engine is a good fairy tale. :-)
Kato,
The weak exhaust manifold is most associated with, and prevalent the later (>'88 model) cars. Also, most of the failures is in the same place(s).
This is because Lotus changed the casting, making it lighter and reducing the amount and thickness of the webbing between the runners. It was probably thought that with the adoption of an integral wastegate, which had previously been supported by the exhaust manifold along with it's own heavy cast iron adapter, that the part could be leaned out as it were.
The manifolds on the earlier cars have been known to crack as well, but at a much lesser rate. Their failure is more associated with heating and cooling of the manifold rather than a lack of material present. Happy Motoring!...Jim'85TE
The weak exhaust manifold is most associated with, and prevalent the later (>'88 model) cars. Also, most of the failures is in the same place(s).
This is because Lotus changed the casting, making it lighter and reducing the amount and thickness of the webbing between the runners. It was probably thought that with the adoption of an integral wastegate, which had previously been supported by the exhaust manifold along with it's own heavy cast iron adapter, that the part could be leaned out as it were.
The manifolds on the earlier cars have been known to crack as well, but at a much lesser rate. Their failure is more associated with heating and cooling of the manifold rather than a lack of material present. Happy Motoring!...Jim'85TE
roadburner said:
And that you have to remove the whole engine is a good fairy tale. :-)
I don't know about fairy tale but I couldn't get my manifold off without removing the engine. Not enough room. I guess perhaps there are certain tools that may make it easier but I don't know what they are. Anyone else know?
Mark 88 Turbo
Hi,
my friend got only one little problem with one bolt.
He has done the whole job without any special tools.
The problem of these cracked manifolds is that all screws are to tight.So the manifold could'nt move(small clearance) during the time of heating up and cooling down.20 NM are enough.
my friend got only one little problem with one bolt.
He has done the whole job without any special tools.
The problem of these cracked manifolds is that all screws are to tight.So the manifold could'nt move(small clearance) during the time of heating up and cooling down.20 NM are enough.
roadburner said:
Hi,
my friend got only one little problem with one bolt.
He has done the whole job without any special tools.
The problem of these cracked manifolds is that all screws are to tight.So the manifold could'nt move(small clearance) during the time of heating up and cooling down.20 NM are enough.
Hi,
You make a good point, often the failure is linked to overtightening the manifold to insure the flange does not leak. The machining on these isn't great, so they are prone to leaking. One way to eliminate this to to use the multi-laminate racing gaskets, these positively do not leak and so you refrain from overtightening. There are several multi-lam gaskets out there, usually riveted together. But the true race engine gaskets (stamped together with no rivet)are somewhat rare to find. I got mine through an acquaintance from Nigel @ London Lotus Center. In addition to sealing better, they are reusable at least 3 times whereas the stock gaskets should/need to be replaced each time the manifold is loosened. Hope this helps. Happy Motoring!...Jim'85TE
Hi,
As far as removal, there is a tight clearance between the webbing, runners and the bolts. It helps to take a 13mm box wrench (closed-end spanner for our limey cousins) and grind the outside on a grinder. This usually affords enough clearance to get on the nuts. As an alternative, many Indy Lotus parts suppliers offer replacement nuts with a 10mm head, but the same ID and thread as the original. That extra 2mm can make all the difference. If removing the manifold, I highly recommend switching to these nuts as they make any future work a breeze. Happy Motoring!...Jim'85TE
As far as removal, there is a tight clearance between the webbing, runners and the bolts. It helps to take a 13mm box wrench (closed-end spanner for our limey cousins) and grind the outside on a grinder. This usually affords enough clearance to get on the nuts. As an alternative, many Indy Lotus parts suppliers offer replacement nuts with a 10mm head, but the same ID and thread as the original. That extra 2mm can make all the difference. If removing the manifold, I highly recommend switching to these nuts as they make any future work a breeze. Happy Motoring!...Jim'85TE
Hey Jim,
I am already accumulating a collection of special tools for this Lotus. Have a 13mm combination wrench with the box end bent to a S in 3D to get to the front bolt on the reverse lockout block thingie. Pawn shops are great sources for tools to do this to. Really hate doing that to my good Craftsman tools, but one from the big bin at the pawn shop for U$0.50 doesn't hurt my feelings.
My car was serviced at a prominent Left Coast shop known for tightening the heck out of everything. Took a 1/2" breaker bar and a socket to get the oil drain plug off. Almost as much to get the oil filter off. Others who went there have had the same comments. I hope he didn't do that to my exhaust manifold.
Dr.Hess
I am already accumulating a collection of special tools for this Lotus. Have a 13mm combination wrench with the box end bent to a S in 3D to get to the front bolt on the reverse lockout block thingie. Pawn shops are great sources for tools to do this to. Really hate doing that to my good Craftsman tools, but one from the big bin at the pawn shop for U$0.50 doesn't hurt my feelings.
My car was serviced at a prominent Left Coast shop known for tightening the heck out of everything. Took a 1/2" breaker bar and a socket to get the oil drain plug off. Almost as much to get the oil filter off. Others who went there have had the same comments. I hope he didn't do that to my exhaust manifold.
Dr.Hess
I know this is a bit of a deceased thread, but it has haunted me since reading it.
The big problem with technical forums like this is it can frighten the $hit out of DIY dunderheads like me, often unneccassarily. As far as I am aware my GT3's manifold is OK, but there is a nice little country blast locally that I am well familiar with (but haven't taken the wedge on yet) that involves a trip over the hills and dales culminating in a trip through a river ford. From what I have read I should avoid this like the plague, right??? Also if I get a new stainless exhaust built up on the car (which hopefully should happen soon) can the existing manifold be replaced at the same time with a custom tubular set-up, or are there things built into the standard casting that cannot be replicated; brackets, mountings etc???
Finally, should all the above be impossible is wrapping the existing manifold and pipework in the heat insulation cloth stuff you see in racing accessory catalogues going to provide any protection??? (and please don't snigger at my incompetence, I haven't had it long enough to see it on ramps yet!)
Cheers
Mark
The big problem with technical forums like this is it can frighten the $hit out of DIY dunderheads like me, often unneccassarily. As far as I am aware my GT3's manifold is OK, but there is a nice little country blast locally that I am well familiar with (but haven't taken the wedge on yet) that involves a trip over the hills and dales culminating in a trip through a river ford. From what I have read I should avoid this like the plague, right??? Also if I get a new stainless exhaust built up on the car (which hopefully should happen soon) can the existing manifold be replaced at the same time with a custom tubular set-up, or are there things built into the standard casting that cannot be replicated; brackets, mountings etc???
Finally, should all the above be impossible is wrapping the existing manifold and pipework in the heat insulation cloth stuff you see in racing accessory catalogues going to provide any protection??? (and please don't snigger at my incompetence, I haven't had it long enough to see it on ramps yet!)
Cheers
Mark
Hey Mark,
There is nothing made that can't be duplicated with enough time and effort (or money). There are some pics of a stainless exhaust on LEW, I think, or maybe EFF. Can't remember. I would make a new one from stainless if I needed one, but I do my own work. I would sub out the flanges after the CAD part was done. I made this one:
from scratch out of 304.
I don't know about wrapping the manifolds. Most of what I have read says that wrapping the manifolds leads to an earlier failure, not a later one. People wrap them to keep the heat in, not to protect them. More heat in the exhaust means more heat available to spin the turbo and a cooler engine compartment. It also means more heat in the metal to fatigue it. Some people put an extra spash shield next to the manifold.
Dr.Hess
There is nothing made that can't be duplicated with enough time and effort (or money). There are some pics of a stainless exhaust on LEW, I think, or maybe EFF. Can't remember. I would make a new one from stainless if I needed one, but I do my own work. I would sub out the flanges after the CAD part was done. I made this one:
from scratch out of 304.
I don't know about wrapping the manifolds. Most of what I have read says that wrapping the manifolds leads to an earlier failure, not a later one. People wrap them to keep the heat in, not to protect them. More heat in the exhaust means more heat available to spin the turbo and a cooler engine compartment. It also means more heat in the metal to fatigue it. Some people put an extra spash shield next to the manifold.
Dr.Hess
Being both in the exhaust business AND owning a 91 Esprit SE, there are a couple of things that contribute
to the premature failure of the exhaust manifold. Four cyl engines by nature vibrate more than a V6 or V8. Engineers HAVE to design an exhaust system to compensate for this extra vibration. This is why practially every FWD car has some sort of flex coupling installed in line of the exhaust system to absorb this extra vibration. Try flexing the exhaust system on an Esprit and you will see that this thing just dosn't move and if your motor mounts are getting a little squishy, this will only make matters worse.
So what's the permanant fix, one a torque strap installed near the engine mount will help reduce engine movement. Otherwise a proper exhaust system needs to be installed which would greatly reduce this problem. I am contemplating designing such a system which would utilize a flex pipe and w/wo a cat and with either a stainless magnaflow muffler or magnaflow stainless glasspack. I'd be curious as to weather there would be much demand for such a product.It would most likly cost under $500USD, and should net some extra ponies.
to the premature failure of the exhaust manifold. Four cyl engines by nature vibrate more than a V6 or V8. Engineers HAVE to design an exhaust system to compensate for this extra vibration. This is why practially every FWD car has some sort of flex coupling installed in line of the exhaust system to absorb this extra vibration. Try flexing the exhaust system on an Esprit and you will see that this thing just dosn't move and if your motor mounts are getting a little squishy, this will only make matters worse.
So what's the permanant fix, one a torque strap installed near the engine mount will help reduce engine movement. Otherwise a proper exhaust system needs to be installed which would greatly reduce this problem. I am contemplating designing such a system which would utilize a flex pipe and w/wo a cat and with either a stainless magnaflow muffler or magnaflow stainless glasspack. I'd be curious as to weather there would be much demand for such a product.It would most likly cost under $500USD, and should net some extra ponies.
I'm currently investigating the possibility of getting a stainless steel manifold made up for the 4 cylinder Esprits (turbo). This will come with a 'Life Time Guarantee' which includes cracking.
I will have a better idea in the next two weeks and should be able to give a rough price for the manifold. So if you're in need of a new one, I'd hold off for a while. As hopefully this will be a must have part for 4 cylinder Esprits.
During my investigation I have found out the reason why Lotus never used a stainless steel version. The cast version reduces noise and helped lotus pass all the testing. A fabricated version greatly increases the Exhaust noise (good for us), which would have caused problems meeting regulations. It's also cheaper to cast them, so it was a no-brainer for Lotus.
As soon as I have more information I will post it here.
kato
Lotus Esprit World
I will have a better idea in the next two weeks and should be able to give a rough price for the manifold. So if you're in need of a new one, I'd hold off for a while. As hopefully this will be a must have part for 4 cylinder Esprits.
During my investigation I have found out the reason why Lotus never used a stainless steel version. The cast version reduces noise and helped lotus pass all the testing. A fabricated version greatly increases the Exhaust noise (good for us), which would have caused problems meeting regulations. It's also cheaper to cast them, so it was a no-brainer for Lotus.
As soon as I have more information I will post it here.
kato
Lotus Esprit World
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