Dinan S65 Engines (Club Racing, Stroker, Rebuilds)

[Hujan]

Originally Posted by Dinan_Engineering

Seems like the most popular question is if we use some special rod bearings or run OEM.

The answer is that we run OE bearings. For each journal BMW offers multiple bearing sizes. Each bearing consists of two halves. We mix and match bearing halves so as to achieve the required clearance, as per Dinan specification, which is different from BMW’s specs.

We have over 100 S65/S85 Dinan Stroker engines out on the road and have yet to experience any problems like you see on the factory bearings.

I would encourage anyone that is interested in these club racing engines to reach out and contact the engineering / racing departments with any specific questions as they are much more enlightened on these matters and can give you a thorough technical breakdown. They can be reached by calling our main number or you can PM me and I will pass along the info and someone will get back to you.

Thanks for that information. Would Dinan be willing to provide this same service--mixing and matching the bearings to achieve ideal clearances--on a stock engine? If so, that would be a great service for those of us who are happy with the stock S65 performance, but want some piece of mind for their long-term engine health.

[PandaM3]

Originally Posted by Killerfish2012

They run stock, unmodified; main, rod, and crank bearings.

However they mix and match the different part number rod bearings to get clearance according to their spec... not BMW's spec.

[ilikebmxbikes]

Originally Posted by Richbot

Racing is racing and track days are track days. People need to stop talking like they're the same thing. They ain't.

The Truth

[s85e90]

Originally Posted by Hujan

Thanks for that information. Would Dinan be willing to provide this same service--mixing and matching the bearings to achieve ideal clearances--on a stock engine? If so, that would be a great service for those of us who are happy with the stock S65 performance, but want some piece of mind for their long-term engine health.

Dinan is building these motors on a bench. Everyone else here is buying new bearings and installing them.


How are people measuring the clearance once they swap in the new bearings. I don't believe they are IMO. I guess you ccould install the bearings with some plastigauge and then torque the rod caps and remove to check the clearance but I highly doubt that the shops are doing this.


You know, all these threads about bad clearances from rod bearing tolerances and yet we haven't seen any measurements from the replacements. Makes you wonder. I would imagine the same (replacement) bearings are getting destroyed as well, but we have yet to see any replacement bearings getting replaced. Time will tell, but this isn't a real solution unless you measure everything.

[bigjae1976]

Originally Posted by s85e90

Dinan is building these motors on a bench. Everyone else here is buying new bearings and installing them.


How are people measuring the clearance once they swap in the new bearings. I don't believe they are IMO. I guess you ccould install the bearings with some plastigauge and then torque the rod caps and remove to check the clearance but I highly doubt that the shops are doing this.


You know, all these threads about bad clearances from rod bearing tolerances and yet we haven't seen any measurements from the replacements. Makes you wonder. I would imagine the same (replacement) bearings are getting destroyed as well, but we have yet to see any replacement bearings getting replaced. Time will tell, but this isn't a real solution unless you measure everything.

For preventive bearing replacement, I would imagine that most are just dropping in new OE spec bearings. Should it be plasti guaged?

[K-M3]

Originally Posted by s85e90

Dinan is building these motors on a bench. Everyone else here is buying new bearings and installing them.


How are people measuring the clearance once they swap in the new bearings. I don't believe they are IMO. I guess you ccould install the bearings with some plastigauge and then torque the rod caps and remove to check the clearance but I highly doubt that the shops are doing this.


You know, all these threads about bad clearances from rod bearing tolerances and yet we haven't seen any measurements from the replacements. Makes you wonder. I would imagine the same (replacement) bearings are getting destroyed as well, but we have yet to see any replacement bearings getting replaced. Time will tell, but this isn't a real solution unless you measure everything.

This!!! True..... Very very true. I have been lurking on this thread since it started . I see both points of view ... people claiming a genuine issue n people claiming internet hysteria ..... I do think there maybe an issue , but no definitive solution has come forth

What I am interested in is a follow up on those who installed WPC treated bearings n how they look at the same mileage tht the original bearings looked like when they were changed . One problem with this thou is - if lets say the bearing change interval is 40K to 60K , by the time The WPC bearings are due for replacement , how many people would actually still own the car ... Most I think would have passed on to a subsequent owner .... So the sample size will be even smaller

[PandaM3]

Originally Posted by bigjae1976

For preventive bearing replacement, I would imagine that most are just dropping in new OE spec bearings. Should it be plasti guaged?

I'm curious if the wpc treated bearings are just any random set of rod bearings treated or is it a combination of bearings that give the biggest possible clearance.

If it's any random set, then they can be potentially problematic.

This is a problem if some bearings have proper clearance already from the factory and then they are swap to unmeasured bearings that have tighter clearances.

[bigjae1976]

They are probably just normal clearance OEM bearings.

[hellrotm]

Originally Posted by 8600RPM

I still am not seeing the added value here. I don't think a dedicated track car needs more low-mid range torque of a stroker. I also don't think the cooling system needs a dry sump to be a dedicated track car. So I feel this is a product targeted toward a track audience but the product doesn't make sense for a track dedicated car

The dry sump oil system is the first thing I would address on these motors. I have personally seen multiple motor failures at COTA. Which I believe in some part are due to oil starvation from high sustained cornering G's. A dry sump systems also allows the motor to be mounted lower in the chassis for lower center of gravity.

These motors are not for the random Joe Schmo on bimmerpost. The gentlemen drivers using these engines show up at the track with fully built from ground up racecar, with big budget haulers. They don't think twice about spending the money buying a race prepared motor by Dinan, who has won many races and championships.

[hellrotm]

Originally Posted by Richbot

Racing is racing and track days are track days. People need to stop talking like they're the same thing. They ain't.

Such a simple statement, but so true.

[PerfM5]

Coming from a guy who just replaced his entire motor; 40K isn't bad at all, especially if you take into account what you get out of a fully reengineered engine. Brand new long block straight from BMW is almost 19K and it produces 414 HP.... now start calculating your cost per hosepower gained from there. Think about this, Akrapovic is charging almost 7K just for 10hp... Nuf said.

KEEP UP THE GREAT WORK DINAN!

[Pu-94]

Originally Posted by PERFM3

Coming from a guy who just replaced his entire motor; 40K isn't bad at all, especially if you take into account what you get out of a fully reengineered engine. Brand new long block straight from BMW is almost 19K and it produces 414 HP.... now start calculating your cost per hosepower gained from there. Think about this, Akrapovic is charging almost 7K just for 10hp... Nuf said.

KEEP UP THE GREAT WORK DINAN!

Word! That engine is dope!

[m45]

Dinan... thank you for making insane products like this. LOVE IT!