Porsche Enthusiasts Club Forum

Mainly after advise for oil system, and any mods to keep oil surge/starvation at bay etc, and any other mods to keep engine cool and reliable on track

Will make an oil baffle setup in the sump to keep oil around the pickup.

Also a large aftermarket oil cooler and radiator

Cross drilling crank? Is this worthwhile?

Any other mods people can advise?

Will be rebuilding an engine, and running around the 400hp mark to begin with, more concerned with reliability than pure power at this stage.

A dry sump system has to be the best and safest bet - but no doubt expensive.

David

A dry sump is preferred yes, but too expensive for initial build to get car up and running. If I lunch an engine, then that's the time I will possibly invest in dry sump, but if the car lasts a year or 2 on track without it then I won't be too unhappy.

Hi Nick,

I've recently been going through the same considerations as you for my build and I recently visited EMC so I discussed this with them: in their view it's not worth fitting any baffles and they're of the opinion that starvation/aeration issues are due to using the wrong and/or poor oil. They don't fit any baffles to their motors and they don't even change the oil cooler(!?). I can't agree with the latter point, but their advice on baffles does match up with info and opinions I've read elsewhere. However they build cars to run on 1B rubber so if you're planning on using slicks that might change things.

However changing and reinforcing the oil pickup and using a later sump with the inbuilt scraper would be idea being as the motor isn't in a car...

If you've not seen this already it's worth a read: http://newhillgarage.com/2013/06/25/108 ... explained/

I'm leaving my sump be for the time being, but I am fitting a 16 row oil cooler. Check out my page below for info

BTW I'll soon be getting quotes for a cage instal so I'll be in touch!

Cheers for info. It's a shame the 44 engine has this slight issue but I'm hoping it's something that can be sorted with a little bit of research. Does the 944 s2/968 engine not have the same problem? Lots of n/a race cars out there that seem pretty reliable, whereas you hear of a few turbo engine failures. They have a bit more heat to deal with but that's about it when it comes to lubrication!

I would of thought it would be high revs that cause oil foaming which you might think an n/a engine requires more revs to extract maximum performance, rather than a turbo which will have max torque at a lower rpm and then have power drop off meaning less need to use all the revs.

I'm a risk taker, so will most likely bolt an engine together and use a high quality oil and just see how long it lasts! If it breaks within a year then it will require a dry sump imo to give me confidence it's going to hold together. Of course will upgrade the oil cooler etc.

Give me a shout info@nicksonmotorsport.co.uk regarding cage, I have done a number of cages for 924/944 and have a very good fit and being custom can fabricate to your exact requirements.

I think it is the higher oil temps of the turbo combined with higher than standard rpm that causes the issue but as Rich points out the quality of oil is also a big factor. There is also concern around the quality of the bearings for the higher duty levels in highly tuned turbo track cars. Some have partially addressed the problem in the US by machining the rods to take better quality bearings to reduce the risk of failure rather than go all the way to a dry sump solution. The later sump also helps.

I'd have thought heat management is the issue - particularly with higher HP ("only 400.." ). Heat soak on intercooler (and oil cooler?). Venting / ducting the intercooler to the low pressure area at the front of the bonnet makes sense to get max. airflow. Bigger (or dual) oil coolers as Rich mentioned. Obviously on a track car you can reduce the need for all this by doing shorter sessions.

The "rod mod" bearings also seems a good idea - not expensive either. See rennlist for details..

What we call the big end bearing, Ed?

it's not just the turbo cars that have issues with oil, the N/a's have the same problem and it's not really a heat issue. The issue in the main is aeration (spelling) of No'2 rod bearing and this is purely down to the design of the oilways, not really a problem for street use but track/race use yes especially for circuits with long fast sweeping bends. This is where the correct oil viscosity is critical and the oil needs to be changed far more often than for road use to reduce foaming. The best fight against this would be a crank scrapper, as has been mentioned the later sumps have them but you can buy custom made items (imho better) in both steel and teflon for the 944, steel you file to match your crank exactly, for teflon the crank itself will wear in the scrapper to it's correct profile. I have a steel scrapper fitted to my 400+ car and it's worth every penny for reasons other than what's being discussed here , they are reasonably priced and if fitting it yourself during a rebuild as i did then it's very cheap.

this may help explain what's going on in our engines a little better, http://newhillgarage.com/2013/06/25/108 ... explained/ it's American but don't hold that against him, it's a good guide for those who want to know....

regards

Pete

NB: sorry just noticed that Rich gave the same link.....

For a track engine listen to the people that have raced and won championships with these engines around the world.

yes

There was a quick 944 using a 16 valver in my daughters championship (750 endurance) so I had a chance to talk to the preparation engineer and he takes the balance shafts out but I don't know what else he did.

Whoa that's a contentious one!!! There's a good reason why Porsche included balance shafts on the GTP and why they were carried over to the 944 engine. Legend has it two of the engineers on the LM project had a wager on whether the motor needed balance shafts or not... Apparently the 'non-balance shaft' prototype motor didn't fare up too well.

However there's plenty of decent 4cyl motors that do well without balance shafts, Honda's for example... But mine are staying put, anything to reduce the risk of a cracked oil pickup has to be a good thing!