Nikasil Bores....
Discussion
What happens when they are shot? Obviously you get Ring blow by and they won't hold compression, and consequent high oil consumption.
Can you get a Nikasil block reconditioned? Can the coating and finishing process be undertaken outside of an OEM manufacturing process? Or does it need to be bored/step linered with a conventional material liner?
Can anybody with any expertise on Nikasil advise....
Can you get a Nikasil block reconditioned? Can the coating and finishing process be undertaken outside of an OEM manufacturing process? Or does it need to be bored/step linered with a conventional material liner?
Can anybody with any expertise on Nikasil advise....
Nikasil is used on alloy blocks to allow the piston to run directly in the alloy with no cast iron liner etc, so failure of the coating is pretty much terminal as the alloy behind the coating will get scuffed up very quickly. The usual symptoms on BMW's are poor starting due to loss of compression and high oil consumption.
There are several companies that can replate Nikasil motorcycle cylinders, but I don't know if any would be able to replate the large Jag or BMW engines.
There are several companies that can replate Nikasil motorcycle cylinders, but I don't know if any would be able to replate the large Jag or BMW engines.
hold your horses......the aluminimm BMW blocks are not Nicasil coated, they are acid etched using the Alusil process, whereby the ali is etched away to reveal the silicon particles, and these are so hard wearing that they allow the piston rings to run directly on them........BMW & co have stuck with Alusil for production, but its not particularly good for anything mildly tuned.....it will scuff in no tme......all BMW race engines that I have heard of have been either nicasil coated, or had liners fitted
Ford used Nicasil in the 1700 Puma, and it was OK, but I was involved in the Puma S1600 engines at Mountune (220bhp) and we did have a few nicasil bores delaminate......but we were pushing it!
the most effective solution is to cast in a liner at the production stage, but thats hardly a solution to the aftermarket!
I have heard of people having bores re-plated in the aftermarket, I would ask a piston supplier who they reccomend, as you will tap into their customers knowledge......your first call should be to Omega pistons.....Failing that I would speak to a bike engine tuning company, someone like TTS or Mistral......as re-plating bike engine bores is very common
Ford used Nicasil in the 1700 Puma, and it was OK, but I was involved in the Puma S1600 engines at Mountune (220bhp) and we did have a few nicasil bores delaminate......but we were pushing it!
the most effective solution is to cast in a liner at the production stage, but thats hardly a solution to the aftermarket!
I have heard of people having bores re-plated in the aftermarket, I would ask a piston supplier who they reccomend, as you will tap into their customers knowledge......your first call should be to Omega pistons.....Failing that I would speak to a bike engine tuning company, someone like TTS or Mistral......as re-plating bike engine bores is very common
^ what he said. The whole block is alusil all the way through. If the bores aren't to shagged they can be reclaimed and reringed. I've done this to 944's with some success. If the bores are well out of tolerence then it seems usual to go for a sleeve kit which is bound to be expensive.
Boosted.
Boosted.
ELAN+2 said:
If you are fortunate, they will be removeable liners as on the Lotus 912 engine, just change the liner and pison with rings(or convert to cast iron liners I guess?
Changing to the Cast Iron is not just a swap, on the 900 series, where they 'slip' into the block the Nikosile liners are 1mm bigger dia, I have slevved a et if linners to fit my 910 block and run it up to 9000 rpm with no problen, But i also have a set of made to measure cast iron liners, and I am happier when these are in the block.Berw said:
ELAN+2 said:
If you are fortunate, they will be removeable liners as on the Lotus 912 engine, just change the liner and pison with rings(or convert to cast iron liners I guess?
Changing to the Cast Iron is not just a swap, on the 900 series, where they 'slip' into the block the Nikosile liners are 1mm bigger dia, I have slevved a et if linners to fit my 910 block and run it up to 9000 rpm with no problen, But i also have a set of made to measure cast iron liners, and I am happier when these are in the block.Dear eLAN +2
Must be, I've never seen a conversion KIt, as such, when I bought the 910 block I use, I also bought a set of custom made cast Iron linners, bored +30, to allow the use of JE Pistons. I had a problem using the pistons (real long story), and went back to std pistons for a while, so I converted my 911 liners to fit a 910, had agood job done, but was always a bit unhappy that the sleeving may come loose, I am now hoping I've solved the problem and going back to the +30.
The trouble is, it is only 1mm and the cast iron one's fit, and with sealant they are not so loose that you would notice if you did not know, but I'd hate to think what would happen when it started to rev.
Must be, I've never seen a conversion KIt, as such, when I bought the 910 block I use, I also bought a set of custom made cast Iron linners, bored +30, to allow the use of JE Pistons. I had a problem using the pistons (real long story), and went back to std pistons for a while, so I converted my 911 liners to fit a 910, had agood job done, but was always a bit unhappy that the sleeving may come loose, I am now hoping I've solved the problem and going back to the +30.
The trouble is, it is only 1mm and the cast iron one's fit, and with sealant they are not so loose that you would notice if you did not know, but I'd hate to think what would happen when it started to rev.
Berw said:
Dear eLAN +2
Must be, I've never seen a conversion KIt, as such, when I bought the 910 block I use, I also bought a set of custom made cast Iron linners, bored +30, to allow the use of JE Pistons. I had a problem using the pistons (real long story), and went back to std pistons for a while, so I converted my 911 liners to fit a 910, had agood job done, but was always a bit unhappy that the sleeving may come loose, I am now hoping I've solved the problem and going back to the +30.
The trouble is, it is only 1mm and the cast iron one's fit, and with sealant they are not so loose that you would notice if you did not know, but I'd hate to think what would happen when it started to rev.
I'm a bit hazy as to where i saw the ad, it was along the lines of "doing awy with troublesome nikasil liners" Have you tried QED or Esprit Engineering?Must be, I've never seen a conversion KIt, as such, when I bought the 910 block I use, I also bought a set of custom made cast Iron linners, bored +30, to allow the use of JE Pistons. I had a problem using the pistons (real long story), and went back to std pistons for a while, so I converted my 911 liners to fit a 910, had agood job done, but was always a bit unhappy that the sleeving may come loose, I am now hoping I've solved the problem and going back to the +30.
The trouble is, it is only 1mm and the cast iron one's fit, and with sealant they are not so loose that you would notice if you did not know, but I'd hate to think what would happen when it started to rev.
regards
Mark
Hi Mark
Don't need the kit, I've made up my own, as I say above, I run a 910 block in my track car, and I did not use the Nikosile, as I was told, that the nikosile can 'drop off' at high reve, and that the engine is stiffer with the cast iron, I'm running 9,000 rpm on a regular basis, and never had a problem with the bottom end, so I tend to believe that the bolck is stonger with the Cast iron. Problem I have is con rod stretch, Lotus say it can happen above 7,800 and I get serius stretch above 9,000, hence the limit.
Don't need the kit, I've made up my own, as I say above, I run a 910 block in my track car, and I did not use the Nikosile, as I was told, that the nikosile can 'drop off' at high reve, and that the engine is stiffer with the cast iron, I'm running 9,000 rpm on a regular basis, and never had a problem with the bottom end, so I tend to believe that the bolck is stonger with the Cast iron. Problem I have is con rod stretch, Lotus say it can happen above 7,800 and I get serius stretch above 9,000, hence the limit.
lighter pistons help? then I'd gues you'd have to turn the crank into a swiss cheese to lighten that as well!Hi Mark
Engine is in a Sylva Phoenix, it is a S4 Esprit Block and Crank, now has a worked on S3 head with sport 300 valves, 289 cams with around .47 inch of lift, light fly wheel, paddle clutch, HTD belt, restricted oil to head, improved oil return uprated pump cooler. IT runs JE +30 forged pistons 11.25 -1 cr. So just about the lot you can do, Can not turbo as does not meet the class regs. Problem is thatst con rods stretch at anything over 7,800 rpm. And I've had problems with pistons hitting the head, (not the valves the sqwish area of the head) So I am now gitting a new set of pistons and decking them to hthe top of the head. This will give 70 thou clearence. I have found that I can just get away with 50 thou clearence, so 70 should solve the problem. The interesting Lotus QC problem is that although I bought an unused block, the main parent bore is actually out of true with the to pf the block bu over 20 thou, so if I run all the pistons at the same height 8small end to piston top) Number 1 sticks out of the head by 20 thou more than number 4.
Lotus say that 20thou is 'normal' con rod stretch, but I've actually had as much as 45. Steel rods are the answer but my wife steps in when I mention the price.
Rest of the car is Lotus Sunbeam, with the dog leg box and LSD, there are some pictures on Terato.com, Malaysian Suoper Series Roind One 2007, race 1, if you want to look.
Kelvin
Engine is in a Sylva Phoenix, it is a S4 Esprit Block and Crank, now has a worked on S3 head with sport 300 valves, 289 cams with around .47 inch of lift, light fly wheel, paddle clutch, HTD belt, restricted oil to head, improved oil return uprated pump cooler. IT runs JE +30 forged pistons 11.25 -1 cr. So just about the lot you can do, Can not turbo as does not meet the class regs. Problem is thatst con rods stretch at anything over 7,800 rpm. And I've had problems with pistons hitting the head, (not the valves the sqwish area of the head) So I am now gitting a new set of pistons and decking them to hthe top of the head. This will give 70 thou clearence. I have found that I can just get away with 50 thou clearence, so 70 should solve the problem. The interesting Lotus QC problem is that although I bought an unused block, the main parent bore is actually out of true with the to pf the block bu over 20 thou, so if I run all the pistons at the same height 8small end to piston top) Number 1 sticks out of the head by 20 thou more than number 4.
Lotus say that 20thou is 'normal' con rod stretch, but I've actually had as much as 45. Steel rods are the answer but my wife steps in when I mention the price.
Rest of the car is Lotus Sunbeam, with the dog leg box and LSD, there are some pictures on Terato.com, Malaysian Suoper Series Roind One 2007, race 1, if you want to look.
Kelvin
Wow! thats some engine spec Kelvin, what sort of power are you getting from it? Surely machining the tops of the pistons different amounts will cause balance problems?
For my next project I'm plotting my "Dream" car, it'll look like an S2.2 Elite (sorry but I love the look) with post'89 Excel running gear and a turbo 2.2 engine, to get the turbo in I'll need to space frame the front of the chassis AKA Spyder, but they don't do elite/excel chassis. I'm told the shell needs some mods at the back to fit but it can be done!
I was planning on getting a standard turbo lump or if I can get one for a sensible amount an SE turbo with injection.
regards
Mark
For my next project I'm plotting my "Dream" car, it'll look like an S2.2 Elite (sorry but I love the look) with post'89 Excel running gear and a turbo 2.2 engine, to get the turbo in I'll need to space frame the front of the chassis AKA Spyder, but they don't do elite/excel chassis. I'm told the shell needs some mods at the back to fit but it can be done!
I was planning on getting a standard turbo lump or if I can get one for a sensible amount an SE turbo with injection.
regards
Mark
knighty said:
hold your horses......the aluminimm BMW blocks are not Nicasil coated, they are acid etched using the Alusil process, whereby the ali is etched away to reveal the silicon particles, and these are so hard wearing that they allow the piston rings to run directly on them........BMW & co have stuck with Alusil for production, but its not particularly good for anything mildly tuned.....it will scuff in no tme......all BMW race engines that I have heard of have been either nicasil coated, or had liners fitted
Hold on , bit of duff info there, BMW did use Nikasil .BMW
NIKASIL
2.0 6 cyl
2.5 6 cyl M52
2.8 6 cyl M52
3.0 V8
4.0 V8
ALUSIL
750 V12
3.5 V8
4.4 V8
Also Alusil is not a process , its a material & is not 'etched' to finish but after normal honing using suitable stones it is honed with felt pads that are coated with silicon polishing paste to as you say leave the silicon crystals proud.
Not good for performance ? does just fine in a 650 bhp 5.0 ltr V8 road car after several years & quite a few others with nearly as much power.
I stand corrected, I didnt know BMW also used NicaSil too.......I know they use a cast in steel/Iron liner in their ali V8 Diesel......
yes, correct, the Alusil is not a process as such, its the whole block material......
what is the 5.0 V8 with 650bhp that you talk about?......tuned M5 perhaps?
yes, correct, the Alusil is not a process as such, its the whole block material......
what is the 5.0 V8 with 650bhp that you talk about?......tuned M5 perhaps?
Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff