Engine Refresh

[PSH]

Ok, Interesting info, although my 3.0 block was honed and each bore is also 1mm oversize @ 105mm Which Lindsey Racing did
but i wasn't aware it was nothing other than a hone, unless they did as Serdi do, only 1mm is a lot of material ?

R

Well, not when you think it's 1mm over the diameter, so you're only losing 0.5mm of actual material which in my case was enough to remove a score in No. 2 which was caused by a failed Iridium plug.

Pete

 

[924Srr27l]

True, both sides but .5mm material off the walls is more than a hone surely?

I've got Nippon Denso Iridiums'.........!

R

 

[PSH]

True, both sides but .5mm material off the walls is more than a hone surely?

I've got Nippon Denso Iridiums'.........!

R

Yes, Roger, I'd agree, IMHO that amount would need to be machined, there are places in the US that do this, more so than here, I can't remember details but do remember finding reference to this when building my own engine...btw the sun's out and I've just been for a blast....sometimes I use a little more throttle than usual...still have a big grin on my face now back home.....



Pete

 

[PSH]

sorry just noticed your comment re 'Iridiums'...I'm not familiar with that type nor can I remember which manufacturer failed on my engine? I think that I use NGK's today, or is it, Bosch, I'd have to check. Back when Iridium's were new, some rolling roads refused to run any car fitted with such plugs, the reason given, being the ceramic insulation breaking off which was exactly what happened with me.

Pete

 

[924Srr27l]

True, both sides but .5mm material off the walls is more than a hone surely?
I've got Nippon Denso Iridiums'.........!
R

Yes, Roger, I'd agree, IMHO that amount would need to be machined, there are places in the US that do this, more so than here, I can't remember details but do remember finding reference to this when building my own engine...btw the sun's out and I've just been for a blast....sometimes I use a little more throttle than usual...still have a big grin on my face now back home.....
Pete

Dunno maybe LR did this or not?, but they were very specific to me using "running in Oil" for 500miles, then 20W50 Mineral low detergent for 3000 miles, don;t go anywhere near Fully Syth they said until 3500miles...

I'm just at 3000miles and going Semi Syth soon... Maybe this was because as you mentioned "the Rocks" need to be properly bedded in.

The car was at full chat On 9M's RR with Wayne @ 500 miles from the fresh rebuild, It produced +40bhp more than Porsche's 2.7 so I'm assuming it's all ok!? touching of Wood etc...!

R

 

[PSH]

I would agree with Lindsey, no synthetic until run in, this is to let the rings bed in without glazing up the bores, something that can happen very easily using a fully synthetic on a new engine. They should have also told you to not sit on the motorway at the same speed for long periods, the engine needs to be loaded up. High throttle(not RPM) in high gear to accelerate and then quickly back off to overrun, this is the best way to avoid glazing and bed the rings in, correctly. I'm not a fan of max power on a new engine though, I doubt if the rings had been fully bed in by then? If all is ok today perhaps I'm wrong on that part?

regards

Pete

 

[924Srr27l]

I would agree with Lindsey, no synthetic until run in, this is to let the rings bed in without glazing up the bores, something that can happen very easily using a fully synthetic on a new engine. They should have also told you to not sit on the motorway at the same speed for long periods, the engine needs to be loaded up. High throttle(not RPM) in high gear to accelerate and then quickly back off to overrun, this is the best way to avoid glazing and bed the rings in, correctly. I'm not a fan of max power on a new engine though, I doubt if the rings had been fully bed in by then? If all is ok today perhaps I'm wrong on that part?
regards
Pete

That's exactly what they said, Don;t sit at any RPM for any length of period, and as you say load it, or from memory there exact words don't pussy foot with it! and run it for a few hours at one time.
I've had many years experience running in 2 stroke 14,000RPM Racing engines, so from LR's advice I adopted similar practices where once the Engine is fully warm I loaded it up with short bursts of 3/4 throttle but no more than 4000rpm which was quite difficult because like the 2 strokes it just want to go and will rev freely..

I had a slot with Wayne only 3 days from collecting the car, so I drove from N. Wales to lincs and back on one day and did loads more mileage, 500 in 3 days before Wayne ran her up in anger. Now he has his own place, I'll pop up again soon and check out his premise and get the car on his rollers for a check of the tune.......

R

 

[PSH]

Sounds great Roger, Wayne is the man to use, I must get mine back to him for the final tune, technically I'm still running on the 'run in' map with 55 injectors.. I need to get the 80's, throw the jumper switch to select how aggressive an ignition I want (think I have 3 to chose from) and book in with Wayne. Wayne has worked his magic twice on my car, last time involved the long drive to his old place in Rochdale, iirc nearly 4 hours each way, the return journey was pure magic...

Pete

 

[GPF]

Hi Guys,

Thanks for all the advice. Sorry for the delay in replying - it's a bitch when work starts to get in the way of your personal life !!

Slightly conflicting opinions on the lightweight flywheel there. I can see what you mean Roger, but I'm not too worried about those effects - I can live with that if it spins up a bit quicker so I think I'm with Thom on this occasion.

As for cylinder ovality, yes I do wonder about that Blade - we'll have to see. Not come across the windage ports before but looking into them a little I can definitely see the point. I'll find about that but not sure an OPC will be up for it - maybe I could send the block somewhere. I did wonder about having oil sprayers fitted, but again, maybe that's a bit much for them too

I also wonder about fitting a crank scraper.

As for the "just go 3.0"........stop it []

Edh........also stop it [] (but thanks mate!!) If someone comes up with some rods or pistons though.......

Yes Paul, nice to hear from too pal. Yep, it's at the Leicester (Thurmaston) one. As for timescales they said with a project like this they like to charge by the month.......not sure about that!!

 

[Diver944]

As for timescales they said with a project like this they like to charge by the month.......not sure about that!!

Eek

I think it's time to do the same thing with my S2 this year. The oil consumption is getting silly now and I know it is very much down on power. I couldn't live without it for months though, hopefully weeks, and I don't think I could stretch to OPC prices either

 

[PSH]

As for timescales they said with a project like this they like to charge by the month.......not sure about that!!

Eek

I think it's time to do the same thing with my S2 this year. The oil consumption is getting silly now and I know it is very much down on power. I couldn't live without it for months though, hopefully weeks, and I don't think I could stretch to OPC prices either

Hi Paul

It's frightening how much rebuilding a 944 engine actually costs, I couldn't have done it if paying someone, most certainly not an OPC. Rebuild parts are crazy too...IIRC a genuine set of oversized (actually undersized) bearings are around 3 to 4 times the cost of a standard set, I wouldn't advise using aftermarket parts here though.

Graham, regarding machining I can fully recommend SERDI UK based in Uxbridge, they should be able to source pistons if the bores are out of spec too. Be sure to get new sleeves machined for the rods, IIRC they are only brass, I guarantee you that these will be worn now and this is the only real weak point on these great engines, in particular for Rod no. 2, especially if the car is used on track.

Regarding some of the other points mentioned
crank scraper... most certainly, it helps greatly in the response of the engine not having all that mass stuck to the crank.
Lightened flywheel...I'm not a fan of going overboard here, nor would I use a lightened crank, not unless you want a racing car for santa pod or such, for a road car...no. However, having said that my own flywheel has been machined to remove all of the scorings, this, in fact, is now down to just below Porsche's minimum so I guess in essence is a little lightened. I would most certainly advise having the flywheel machined to remove any marks, the clutch will work far better and last longer too.

Good luck with the build, there's nothing quite like a nice new fresh engine, well not once your head has accepted that nothing is going to fail.....I'm very much loving mine of late....

Pete

 

[924Srr27l]

It's frightening how much rebuilding a 944 engine actually costs, I couldn't have done it if paying someone, most certainly not an OPC. Rebuild parts are crazy too...IIRC a genuine set of oversized (actually undersized) bearings are around 3 to 4 times the cost of a standard set, I wouldn't advise using aftermarket parts here though.

Lightened flywheel...I'm not a fan of going overboard here, nor would I use a lightened crank, not unless you want a racing car for santa pod or such, for a road car...no.
Pete

I guess we all go from our experiences and recommend or discourage them from what we find from our own builds and modifications..
So far so good with the Glycol bearings I have fitted from LR, for sure the cost of rebuilding a engine properly (No stone unturned) soon adds to any thousands and it's not just the parts that are costly (more so when they are imported in a crate from the USA) but the building can be too, although I got lucky here with a low hourly rate from a very experienced builder.

The whole lightweight Flwheel thing is and always will be a difficult one to answer for road use, anyone that own's a stock 952 and even a modded one no more than 300bhp who sampled my N/A would I think be totally impressed how quick the rpm and throttle feels on all the lightweight spinning parts, however I agree the same set up on a blown motor and at stock weight could be a pain in the arse...

R

 

[GPF]

Paul, take it to Thurmaston now - perhaps we can get a bulk buy discount, I think I could use one []

Thanks for the advice Pete. Any idea on supplier for a crank scraper? how much is involved in fitting?

 

[PSH]

use one []

Thanks for the advice Pete. Any idea on supplier for a crank scraper? how much is involved in fitting?

I got mine from Ishihara-Johnson ..link http://www.crank-scrapers.com/Porsche_944.html.. they did two types when i bought mine, one made from steel and the other from teflon. This is a job for when you have the main bearing caps off as iirc they use these to secure it to the engine. They both mount in the same way but if using steel you need to do test fits and remove material (simple filing job) until the scraper clears the crank when rotated, make sure to allow enough room for the crank's end float, it's prudent to leave a little more room allowing for the bearings wearing in as time progresses. with the teflon type it's just a matter of fitting and letting the crank wear it's way through the material to form the shape, i'd take most of the excess of first personally.

IIRC there are pictures of mine (steel) being fitted in my build thread if you can find the thread that is, I've given up...lol

Pete

 

[blade7]

Not sure if all years are the same but my 2.7 has a crank scraper combined with the baffle in the bottom of the sump.

 

[944Turbo]

IIRC there are pictures of mine (steel) being fitted in my build thread if you can find the thread that is, I've given up...lol

Pete

found it for you
https://www.porscheclubgb.com/forum/tm.aspx?m=705721&high=crank+scraper

 

[PSH]

thank's Tony..... how did you do that? I tried a number of times and couldn't get the search engine to go back far enough...

Pete

edit: Graham I just checked...crank scraper details are on page 5..thanks again Tony for finding this for me..

 

[blade7]

I think the 2.7/3.0 blocks with shallower water jackets rely more on the oil thrown off the crank for piston cooling than the 2.5 blocks. Why else would Porsche fit the oil squirters to the later 968 block ?

 

[924Srr27l]

I think the 2.7/3.0 blocks with shallower water jackets rely more on the oil thrown off the crank for piston cooling than the 2.5 blocks. Why else would Porsche fit the oil squirters to the later 968 block ?

Is your sump the same as this one ?

http://www.ebay.co.uk/itm/Porsche-944-S2-Engine-Sump-944-101-204-0R-944-Oil-Sump-944-Oil-Pan-/272629574281?hash=item3f79fd2a89:g:rJ8AAOSwEetV~Uo2

I read the reduced water jacket as something learnt at Le mans?
If your thinking the bigger (104mm) bore blocks rely more on Oil thrown off the crank why do they have the crank scrapper / baffled sump ?
Only this will restrict the amount of Oil wouldn't it? Especially if the 100mm blocks didn't have the scraper surely it would be those that would have more
Oil thrown up to the undersize of the Pistons.. ?

I wonder if the 968 also has this same design sump?


R

 

[blade7]

I think it's the same, ie a plastic and cast in scraper and incidentally a turbo oil drain port. I'm guessing it's not as close a fit as the aftermarket scrapers so there's more oil throw.