Colt Cams Stage 2 Upgrade on PD Motor (before and after dyno)

Bosch specifies 4800 RPM max. for PD injectors.

5200 RPM is too much, and 5000 RPM may be pushing it. Often you won't hear valve and piston contact, but if you take the head off you may see valve marks. I have seen a few highly modified PD TDIs with the valve marks.

4800 RPM is a reasonable limit for most PD engines, but some clients want more. Given that good power can be made at 5000-6000 RPM with good airflow (especially with nitrous oxide), it's understandably hard to resist.

I guess I've pushed mine a few times running logs to 4900. It wants to quit there any way.

jjordan11 said:

That's good news. Do you think the valve float was from emp, or over-rev? If it was over rev, what rpms would you say it happened, so I can avoid that .

Jon

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It was because my turbo seal went and the engine went over 6K RPM before I got it under control.

I was initially running a 5300RPM limit, but really, it was a waste of time. The power drops of quick past 4600RPM unless you have some serious porting and larger turbo (obviously something much bigger than a GT2056V.


EDIT - What Malone says ^

TDIsyncro said:

I have over 60,000 km on mine and it looks great. I had sent it to Geoff for his inspection while I had my engine apart from the runaway. All looked good except one lobe that had a light crash mark on the down ramp side from valve float and piston valve contact.

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Are you sure it's from piston to valve contact? all my exh valves kissed the pisons because I forgot that BHW pistons have less deep relieves than ASV pistons, so the valves were laid in the head at stock ASV specs.. suprisingly the engine still started well and ran very strong and dynoed 255hp smokefree.. I discovered that the vales were leaking when I pressurized the cylinder as I was going to change the valve stem seals to lower ones to be able to make enough lift..


all valves were still straight, cam looked mint, but offcourse the lifters where screwed

Mark@MaloneTuning said:

Bosch specifies 4800 RPM max. for PD injectors.

5200 RPM is too much, and 5000 RPM may be pushing it. Often you won't hear valve and piston contact, but if you take the head off you may see valve marks. I have seen a few highly modified PD TDIs with the valve marks.

4800 RPM is a reasonable limit for most PD engines, but some clients want more. Given that good power can be made at 5000-6000 RPM with good airflow (especially with nitrous oxide), it's understandably hard to resist.

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Old thread but why?

we have revved a PD to 7000rpm, not for long mind.

The Arosa bounces off the 6000rpm limiter all the time, never seen any wear on the PD injector or lobes or rockers at all.

https://www.youtube.com/watch?v=kz6lKGyyfn8