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-   -   Sirio engines thread (https://www.rctech.net/forum/offroad-nitro-engine-forum/29456-sirio-engines-thread.html)

stefan 02-14-2009 02:25 AM

I would be interested in how you guys would compare the XXX to the EVO 4 STI?

The reason I am asking is , that the EVO4 STI has a coated crankshaft which the XXX doesn't have. So if the performance is similar, I would personally rather stick with the EVO4.

I hate it when I have a great running engine and the crankpin is wearing down.

Roelof 02-14-2009 02:52 AM

You can alway send the crankshaft to a company specialized in DLC coatings....

stefan 02-14-2009 02:58 AM


Originally Posted by Roelof (Post 5429933)
You can alway send the crankshaft to a company specialized in DLC coatings....

First of all, having a crankshaft coated is very critical. We have once sent 5 cranks for coating for €25 each. on 3 of those cranks the crank pin broke of within the first liter.

Secondly, if the performance of the EVO4 is just marginally lower than the XXX, why would I buy an engine that is €50 more expensive and then spend an additional € 20-30 to have the crank coated.

In this case, the XXX would have to be much much better than the EVO.
That's the reason I asked the question about comparison of EVO 4 STI and XXX

GREGORY! 02-14-2009 03:53 AM


Originally Posted by stefan (Post 5429938)
First of all, having a crankshaft coated is very critical. We have once sent 5 cranks for coating for €25 each. on 3 of those cranks the crank pin broke of within the first liter.

Secondly, if the performance of the EVO4 is just marginally lower than the XXX, why would I buy an engine that is €50 more expensive and then spend an additional € 20-30 to have the crank coated.

In this case, the XXX would have to be much much better than the EVO.
That's the reason I asked the question about comparison of EVO 4 STI and XXX

stefan what do you believe cause this break?
maybe they heat them very much to make the coat?

stefan 02-14-2009 04:18 AM


Originally Posted by GREGORY! (Post 5430011)
stefan what do you believe cause this break?
maybe they heat them very much to make the coat?

the surface treatment is changing the crystalline (molecular) structure of metal.

It seems that the treatment, if not done correctly, is weakening areas that have been hardened during the production of the crank, i.e. the crank pin.

Just my theory though..

Roelof 02-14-2009 04:26 AM

The coating will make the pin a few microns thicker, you have to take away some microns from the pin or otherwise drill up the conrod. We keep it by a hard metal pin pressed in the crank, no wear at all.

stefan 02-14-2009 05:19 AM


Originally Posted by Roelof (Post 5430044)
The coating will make the pin a few microns thicker, you have to take away some microns from the pin or otherwise drill up the conrod. We keep it by a hard metal pin pressed in the crank, no wear at all.

Roelof, no offence, but I have done this plenty of times. In the States I had found a galvanic shop that was able to hard chrome only the crank pin and this worked perfect.
It is absolutely clear that the pin has to be lapped after coating.

The problem is, that most coatings won't work.

I would like to get back to my original question, please!

elche_83 02-15-2009 11:45 PM

i was wondering if anyone could anwser my question about the xxx motor.cheers.

NinjaRacer 02-16-2009 12:38 PM


Originally Posted by elche_83 (Post 5437285)
i was wondering if anyone could anwser my question about the xxx motor.cheers.

I think Sirio is comming out with a new xxx in a few months.

stefan 02-16-2009 10:17 PM


Originally Posted by NinjaRacer (Post 5439579)
I think Sirio is comming out with a new xxx in a few months.

XXX STI ?

impalabob64 02-17-2009 02:26 PM

lookin 4
 
Hey guys lookin for WCR s21 short stroke parts P/S let me know.Thanks Bobby Watson

20 SMOKE 02-17-2009 02:56 PM

what glow plugs work in the 21 other than siro

impalabob64 02-17-2009 03:01 PM

Picco
 
Picco or IDM work perfect:nod:

20 SMOKE 02-17-2009 04:45 PM


Originally Posted by impalabob64 (Post 5445399)
Picco or IDM work perfect:nod:

standard plug, I thought the turbo's were

stefan 02-18-2009 01:18 AM


Originally Posted by impalabob64 (Post 5445399)
Picco or IDM work perfect:nod:

IDM plug = Sirio plug :nod:


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