Crank Scraper crankshaft scraper [Merged 12-6]

[Sinner]

I was wodering if anyone has used one on the 420A. I found one on ebay http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2412290757&category=6770. From my past expirence with V8's I know they are a good thing to used and gain some people 10-15 horse on a V8, but I have yet to hear anything about them for a four cylinder motor. I plan on replacing my rod bearing cause they went bad and I was wodering if this might be worth my money to put in while I'm there.

 

[highbooster]

49.99 for 7-9+ hp is good. 30-40 dollars for 7-9+ hp is great. A group buy just may shake some of my dsm brothers off the fence. What do you say?

 

[Defiant]

A group buy just may shake some of my dsm brothers off the fence. What do you say?

That group buys are specifically not allowed on DSMtuners.

 

[highbooster]

I got mines on ebay. 49.95 shipped. It came well packed and very quick. It is overbuilt and SOLID. I AM 100 percent HAPPY with it so far.

 

[flashoverride]

Hey Kevin Johson,

I picked up a teflon scraper from you a while back and due to a giant backlog and the fact that it's hard to find parts for the 420A, the tuner shop is just now getting all the mods (including the scraper) installed. I'll let you guys know how it turns out, but it will be difficult to seperate out the gains I think I'll see if Nick from Pina can provide any pics of the install or if that is a no-go.

To put in my 2 cents, the thoery behind these pieces seems solid. I picked up a teflon scraper (from Kevin) where the teflon actually is supposed to touch the crank and I'll let everyone know how that goes.

Aaron

 

[Defiant]

To put in my 2 cents, the thoery behind these pieces seems solid. I picked up a teflon scraper (from Kevin) where the teflon actually is supposed to touch the crank and I'll let everyone know how that goes.

I don't like the sound of that. Do let us know.

 

[SnoopySLR]

To put in my 2 cents, the thoery behind these pieces seems solid. I picked up a teflon scraper (from Kevin) where the teflon actually is supposed to touch the crank and I'll let everyone know how that goes.

Aaron

umm... the second the crank hits it, its going to break. If it doesn't its going to grind it down until it doesn't touch... sending teflon through your motor. Sounds like a good idea to me.

 

[Kevin Johnson]

Hey, finally made a setup for the 928 after talking with your Uncle way back. There are some dyno results on our home page for the 2.4 setup. The one for the DSM 420A is very similar in design. Maybe someday I will get to further mods for the Mitsubishi engines -- got a lot of projects backed up.

Kevin

kevin nice to talk to ya again, i gotta say man i was really impressed w. the unit i picked up from you. the only thing i had to do was modify it a bit to fit with the apr main studs. anyway i may need to get another one here soon for my 2g.

 

[v8s_are_slow]

I'm gonna get one of these for my car. I know MachV sells them for $50 and then the other place, http://www.crank-scrapers.com that has the teflon ones.

I'm Curious as to anyone using the teflon one's because of the fact that the teflon DOES touch the crank unlike the others I guess. Wondering if telfon would be floating around in my motor while it's seating in or whatever. Who knows more about em? Thanks for any info!

Scott

 

[Defiant]

I'm not keen on that idea. I don't want to feed chunks of anything to my oil pump.

I don't believe his test numbers, although oil scrapers are an okay thing. I'm very discomforted with the idea of having the big, expensive end of the engine being used as a mill.

 

[bjones18]

I guess this is an alternate method to knife edging the crank. Which is performed on the trailing edge of the crank. More aerodyanmic, less oil-cloud.

Teflon is extremely tough stuff. Believe it or not, Teflon rubbing on steel will wear down the steel. In this case the Teflon is thin, and probably will not wear down the counter weights, but it would not be good if a small piece were to "machine-off" and get past your oil filter through a passage into a main bearing.

The OEMs can support less than 1mm tolerances, make a million parts for their specific engine, and they know you'll be back for free service if something goes wrong.

If something went wrong with this "one-z two-z" quantity part, you might get a replacement part for free.

I do not think the value vs risk equation works for this device (value = HP/$ , risk = how F**d am I if it goes bad).

If you race and are into your engine every other month, it might be worth a try.

 

[TSIfreek]

Well I used one(Accucally the fist one the company made 4 the 4g63) and found it slightly seaping oil out of the engine on the scraper side. The back of the pan block was bone dry. I think it was scraping so much off that it was causing pressure issue at the sealing the pan and the scraper. I just took it out this weekend because I am putting in a new trany and desided to check it out and this was the problem. I hate any type of and oil leak!!! I have one set up for ARP main studs and trimed already for the crank if anyone wants it its in perfect shape. I would use it but not worth the leak ( I will just be running 3.5 qurts in the pan to keep the crank off the oil. I will give anyone a killer deal on it if they want it I can provide a pic if nesasary.

 

[Suparata]

... I will just be running 3.5 qurts in the pan to keep the crank off the oil...

You do that and I will kill you with my bare hands. I will do it slowly.

 

[Wil]

I will just be running 3.5 qurts in the pan to keep the crank off the oil.

I did that to the motor of my very first DSM. I started to get massive blow-by pretty quick. Not a good thing to do. And just forget about trying to rebuild the turbo by the time you get to this point.

But hey, I was a noob to all this 10 years ago, .

 

[Kevin Johnson]

Try using the Mopar rear differential RTV gasket maker. It is specifically formulated for use with synthetic lubricants.

Well I used one(Accucally the fist one the company made 4 the 4g63) and found it slightly seaping oil out of the engine on the scraper side. The back of the pan block was bone dry. I think it was scraping so much off that it was causing pressure issue at the sealing the pan and the scraper. I just took it out this weekend because I am putting in a new trany and desided to check it out and this was the problem. I hate any type of and oil leak!!! I have one set up for ARP main studs and trimed already for the crank if anyone wants it its in perfect shape. I would use it but not worth the leak ( I will just be running 3.5 qurts in the pan to keep the crank off the oil. I will give anyone a killer deal on it if they want it I can provide a pic if nesasary.

 

[Kevin Johnson]

I guess this is an alternate method to knife edging the crank. Which is performed on the trailing edge of the crank. More aerodyanmic, less oil-cloud.

Teflon is extremely tough stuff. Believe it or not, Teflon rubbing on steel will wear down the steel. In this case the Teflon is thin, and probably will not wear down the counter weights, but it would not be good if a small piece were to "machine-off" and get past your oil filter through a passage into a main bearing.

The OEMs can support less than 1mm tolerances, make a million parts for their specific engine, and they know you'll be back for free service if something goes wrong.

If something went wrong with this "one-z two-z" quantity part, you might get a replacement part for free.

I do not think the value vs risk equation works for this device (value = HP/$ , risk = how F**d am I if it goes bad).

If you race and are into your engine every other month, it might be worth a try.

I am sure you are aware of the millions of Teflon valve stem seal scrapers in service for at least the past 25 years. Same idea different application.

If your oil filter allows such a small particle of Teflon through then it will pass a similarly sized particle of nice abrasive metal through as well. I suggest using a better filter.

Have you worked with pure Teflon sheeting? It has the consistency of hard wax and abrades quite easily. Running water (and I am sure oil as well) will eventually wear hardened steel as well. You are also forgetting the hydrodynamic cushion of oil between the Teflon and steel (ala valve stem seals).

Just use a steel scraper if you are really worried. They work very well and in fact are OEM on many stock engines. The 1mm recommended clearance gives a roughly 10 fold safety factor in clearance -- that's so that it is very difficult to do something wrong if you follow the installation procedures.

 

[Kevin Johnson]

That's why it is so great that Ed Peters did independant testing.

His dyno room is so sensitive that it measures the effect of someone walking through the room. He held the ambient temp to plus or minus .5 degrees. He scrapped a day of dyno testing because it was raining and it was too difficult to hold the humidity constant.

You tell me which other dynos you know of that are that closely controlled... It's OEM level and, yes, he does test parts for OEM manufacturers.



I went through this with the 420A engine and not one person ---- not ONE ---- realized that the original 420A had a scraper as OEM equipment.

The numbers thing is really a bit tired now -- gets old after a while.

Here is Scott Seck running one of our Teflon scrapers...

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I'm not keen on that idea. I don't want to feed chunks of anything to my oil pump.

I don't believe his test numbers, although oil scrapers are an okay thing. I'm very discomforted with the idea of having the big, expensive end of the engine being used as a mill.

 

[v8s_are_slow]

I'm curious as to how close to the crank these are cut when they are 1st installed. Makes me wonder how much they have to wear down. Any problems that you know of, having chunks of the teflon breaking off? This reminds me of an interupted cut on a milling machine. The cutting tool doesn't touch the material it's cutting 100% of the time and if you have the wrong cutting tool, you can destroy it. Kind of the same thing here that I'm wondering about. Having the counterweights slamming into teflon without breaking it. Wanna make sure it's safe before I invest in something of this nature. Sure it's a cheap mod, and probably well worth it but wanna check my p's and q's.

 

[Kevin Johnson]

I'm curious as to how close to the crank these are cut when they are 1st installed. Makes me wonder how much they have to wear down. Any problems that you know of, having chunks of the teflon breaking off? This reminds me of an interupted cut on a milling machine. The cutting tool doesn't touch the material it's cutting 100% of the time and if you have the wrong cutting tool, you can destroy it. Kind of the same thing here that I'm wondering about. Having the counterweights slamming into teflon without breaking it. Wanna make sure it's safe before I invest in something of this nature. Sure it's a cheap mod, and probably well worth it but wanna check my p's and q's.

They are supplied with excess Teflon (all the "scraper" areas on the steel pattern have at least 3mm added to them). Prussian blue indicating grease is supplied to smear on the counterweights and rods and it will make marks on the Teflon where it is rubbing. The installer is instructed to trim these areas away until there is light contact with the rotating assembly.

Light contact means there is a small amount of drag -- the Teflon may move very slightly but the assembly is still easy to turn by hand. When I did the G10 pattern you can see on our website I deliberately left the Teflon in very heavy contact to try to elicit problems and they simply did not occur. Heavy contact means there was significant drag as I rotated the crank by hand. It does not mean that the assembly came to a dead stop and then I forced it through.

The Teflon material is very close to dead soft with just a small amount of memory so it does move as well as abrade away.

Luke Wilcox did a write-up on Honda-Tech for the B series scraper (link below). I helped Scott Seck install his while the engine was in the car but I agree with Luke that is is much, much easier to do this to an engine on a stand. I also installed the Teflon scraper on the Suzuki engine while it was still in the car.

http://www.honda-tech.com/zerothread?id=1198975

 

[Defiant]

I will just be running 3.5 qurts in the pan to keep the crank off the oil.

Kind of pointless. The crank never touches the oil in the sump.

 

[TSIfreek]

Thanks defiant I was under the impression that the crank slightly hit the oil but I guess thats not the case.

Again I used one of kevins scrapers. When you get the teflon scraper you need to trim a little of the back side of the scraper so it doesnt accually ride on the crank you want it to hit a little but not drag on it. It takes time to set up and install it just right and is kind of a pain but if you what the best scraper there is than I guess its worth it but I stoped running it because I was getting a seaping oil leak all along the scraper side of the pan I intalled it when I had the motor out so the RTV was applyed correctly to both the pan and the scraper. May not happen with you but just what I expereanced.

 

[Kevin Johnson]

The installation is typical of many oem parts, for example the Toyota 4AGZE has a windage tray that uses the full circumference of the flat oil pan rail and it and the pan are sealed to the block using RTV material. I do know that Permatex Ultra Grey passed Honda's 10 year/100,000 mile testing for a form in place gasket material so that is at least one brand that should not give you problems.

Here are some common causes of leaks with RTV:

1) Dirty or oily surface. If there is even a microscopic film of dirt, old gasket material or oil on the rail, scraper or pan when you place RTV over that you are building in a potential leak from the very start.

2) Insufficient material used so un-noticed gaps are created. Many times engine builders use too little RTV because they are trying to avoid unsightly blobs or oozing of the RTV from the joint.

3) Improper removal of excess RTV. Once the RTV has reached the initial set stage (becomes slightly rubbery or stiff) you absolutely must not attempt to remove excess material (as in the blobs or oozing in 2.). There is a new product on the market from 3M (I believe) that utilizes this effect: adhesive wall hangers that are removed by pulling on the lower edge of the adhesive layer. When you do this with RTV you are pulling away the RTV from either or both surfaces you are attempting to seal. It is not an obvious thing and may only extend part way through the joint but it is definitely a weak spot and combined with 1. may easily create a leak.

If you want to remove excess RTV you should wait until the material is fully cured and then trim it, without tugging on it, with a razor or similar edged instrument. This will avoid stress on the joint.

4) Not allowing the RTV to fully cure before placing the engine into service. I have a tube of Permatex Ultra-Grey in front of me and the instructions state that it requires 24 hours to fully cure. Remember that many silicone products use water in the air to react with so if you live in a low humidity area it may require a longer set time for full strength. Similarly with temperature: like any chemical reaction the cure time is increased or reduced depending on the ambient temperature.

5) Installing a part and then removing and replacing it or shifting it while the cure is under way. Some of the material may be partially cured and all manner of air gaps or shearing gaps as in 2 and 3 can be introduced. It is best to start over with a fresh layer of RTV on a surface cleaned of previously applied RTV. Yes, it is a pain.


Hope these ideas help.

Thanks defiant I was under the impression that the crank slightly hit the crank but I guess thats not the case.

Again I used one of kevins scrapers. When you get the teflon scraper you need to trim a little of the back side of the scraper so it doesnt accually ride on the crank you want it to hit a little but not drag on it. It takes time to set up and install it just right and is kind of a pain but if you what the best scraper there is than I guess its worth it but I stoped running it because I was getting a seaping oil leak all along the scraper side of the pan I intalled it when I had the motor out so the RTV was applyed correctly to both the pan and the scraper. May not happen with you but just what I expereanced.

 

[TSIfreek]

Yea I really hate the stuff I would rather use a gasket. Great post by the way kevin all very true.

 

[v8s_are_slow]

Well, I didn't get the one with the teflon but I did get one. Only real problem I'm having at the moment is that this thing really wasn't designed with the ARP main studs in mind. Other than that, it's really a nice solid piece but I'm gonna have a real good amount of grinding to do. Not really in the mood to do THAT much grinding but oh well, if I'm gonna use it, guess I'd better get to work. The piece in the center pretty much just needs to be cut off.

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[Kevin Johnson]

I wanted to pass along the recent experience of one of our other customers. He got one for the 6G72 and subsequently had an oil leak. He removed the scraper and tried sealing the pan again and still had a leak. Seven tries and a new pan later he still had a leak.

One of the suggestions I made was that his pcv system was not working correctly and that he was pressurizing the crank case and forcing the oil to try to seep out of any joint/seal and it turned out that this was the problem. If you have a turbocharged engine this problem would be magnified. Something to keep in mind.

Well I used one(Accucally the fist one the company made 4 the 4g63) and found it slightly seaping oil out of the engine on the scraper side. The back of the pan block was bone dry. I think it was scraping so much off that it was causing pressure issue at the sealing the pan and the scraper. I just took it out this weekend because I am putting in a new trany and desided to check it out and this was the problem. I hate any type of and oil leak!!! I have one set up for ARP main studs and trimed already for the crank if anyone wants it its in perfect shape. I would use it but not worth the leak ( I will just be running 3.5 qurts in the pan to keep the crank off the oil. I will give anyone a killer deal on it if they want it I can provide a pic if nesasary.

 

[Kevin Johnson]

Well, I didn't get the one with the teflon but I did get one. Only real problem I'm having at the moment is that this thing really wasn't designed with the ARP main studs in mind. Other than that, it's really a nice solid piece but I'm gonna have a real good amount of grinding to do. Not really in the mood to do THAT much grinding but oh well, if I'm gonna use it, guess I'd better get to work. The piece in the center pretty much just needs to be cut off.

You guys just need to let me know that you are using studs and I can make a custom scraper with the relief holes for them, no extra charge. Kris took the time to help line everything up with the 1st gen when I only had a 2nd gen block to work with. I now have a 1st gen block and girdles as well.

Here is a pic of Kris's scraper with the ARP reliefs. I can add those easily to a steel scraper, of course.

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I did it for the BMW guys as well. Here is a pic of the now standard M20 scraper with stud reliefs. A couple weeks ago I sent out a modified version of this as well (with smaller holes) as the owner wanted to tie the scraper into the mains/studs.

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