EKO181K - 1972 Porsche 911T 2.5
Moderator: Bootsy
- Darren65
- Nurse, I think I need some assistance
- Posts: 7873
- Joined: Mon Dec 13, 2010 10:55 pm
- Location: North Wiltshire
- Contact:
Re: EKO181K - 1972 Porsche 911T 2.5
...and yesterday I went along to see where we were.....not how I expected the engine to look when it was taken out for a 'service' a few weeks ago....
....whilst I've said previously that this engine has been rebuilt a couple of times that's not strictly the case......the first issue with the pistons touching the heads involved Nick Fulljames having special steel gaskets made to solve the issue, work he carried out free of charge even though the engine had done several thousand hard miles......the second issue with the chain case failure meant the engine was stripped to a short motor and bearings replaced.....the engine cases have never previously been apart since the original build........however this time around we're starting from scratch and making sure everything is perfect and within spec....case line reemed and conrods measured, balancing checks, everything polished, time certs checked/replaced etc etc....
....one thing that was noted is that the mating surface of the barrel decks was not completely flat.....hard to see here but with the cases bored out for 89mm barrels the 2R/3R cases are stretched to their limits, just how they would have been for a 2.5ST engine built back in the day....
....and Gary believes these may well have been the cause of the problem.....
....as Gary explained the steel bolts have a far different expansion rate than the magnesium case and alloy heads and a with a case that can expand by as much as 3mm over a heat cycle this has put extreme pressure on the bolts which in the first instance caused the copper barrel gaskets to be squeezed outwards causing a loss of compression and piston heads to touch and you can even see a slight depression on the later steel gaskets.....it's little wonder the barrel decks surfaces have changed....
....the steel bolts are fine in a regular engine but we'll now upgrade to Dilavar bolts, as did Porsche in the late seventies, which will match the expansion rate of the cases and heads whilst new gaskets will be manufactured and barrel desks machined to suit.....this is all very fine margins of a few thou or so but work that will make this fabulous engine stronger than ever
....whilst I've said previously that this engine has been rebuilt a couple of times that's not strictly the case......the first issue with the pistons touching the heads involved Nick Fulljames having special steel gaskets made to solve the issue, work he carried out free of charge even though the engine had done several thousand hard miles......the second issue with the chain case failure meant the engine was stripped to a short motor and bearings replaced.....the engine cases have never previously been apart since the original build........however this time around we're starting from scratch and making sure everything is perfect and within spec....case line reemed and conrods measured, balancing checks, everything polished, time certs checked/replaced etc etc....
....one thing that was noted is that the mating surface of the barrel decks was not completely flat.....hard to see here but with the cases bored out for 89mm barrels the 2R/3R cases are stretched to their limits, just how they would have been for a 2.5ST engine built back in the day....
....and Gary believes these may well have been the cause of the problem.....
....as Gary explained the steel bolts have a far different expansion rate than the magnesium case and alloy heads and a with a case that can expand by as much as 3mm over a heat cycle this has put extreme pressure on the bolts which in the first instance caused the copper barrel gaskets to be squeezed outwards causing a loss of compression and piston heads to touch and you can even see a slight depression on the later steel gaskets.....it's little wonder the barrel decks surfaces have changed....
....the steel bolts are fine in a regular engine but we'll now upgrade to Dilavar bolts, as did Porsche in the late seventies, which will match the expansion rate of the cases and heads whilst new gaskets will be manufactured and barrel desks machined to suit.....this is all very fine margins of a few thou or so but work that will make this fabulous engine stronger than ever
Darren
72T 2.5... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=56183
73 2.4E ... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=44242
77 Carrera 3.0...to 74 3.0RS ... http://ddk-online.com/phpBB2/viewtopic.php?f=28&t=63389
72T 2.5... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=56183
73 2.4E ... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=44242
77 Carrera 3.0...to 74 3.0RS ... http://ddk-online.com/phpBB2/viewtopic.php?f=28&t=63389
- Darren65
- Nurse, I think I need some assistance
- Posts: 7873
- Joined: Mon Dec 13, 2010 10:55 pm
- Location: North Wiltshire
- Contact:
Re: EKO181K - 1972 Porsche 911T 2.5
....I'm not despondent Feroz....I'm actually relieved to be getting the engine sorted and it's nice to know what was the cause of previous issues and that these are being resolved....I'll be back out driving very soon ....yoda wrote:Chin up Darren - I don’t know of many other early 911 road cars that get used with the same gusto as yours. The set backs are indeed painful (and expensive) but the high points are also very high! Roll on 2019.
...also incredibly grateful to Mike Bainbridge and Gary Cook for taking this on at short notice.....we all know Mike is a true master engineer when it comes to early Porsche gearboxes and I rate Gary as probably the best all round Porsche specialist in the country.....we saw the magnificent job Gary made of Adam's 2.7 build that took him to 5th place at CLM this year on its first run out and even Josh Sadler has Gary building his race engines for him .....
....I'm in safe hands
Cheers,
Darren
72T 2.5... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=56183
73 2.4E ... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=44242
77 Carrera 3.0...to 74 3.0RS ... http://ddk-online.com/phpBB2/viewtopic.php?f=28&t=63389
72T 2.5... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=56183
73 2.4E ... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=44242
77 Carrera 3.0...to 74 3.0RS ... http://ddk-online.com/phpBB2/viewtopic.php?f=28&t=63389
Re: EKO181K - 1972 Porsche 911T 2.5
Fantastic Darren . Will be great to see you in convoy next year
James
1973 911 2.4S
1993 964 C2
2010 987 Spyder
1973 MGB Roadster
Its not how fast you go, but how you go fast
1973 911 2.4S
1993 964 C2
2010 987 Spyder
1973 MGB Roadster
Its not how fast you go, but how you go fast
-
- Nurse, I think I need some assistance
- Posts: 18955
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: EKO181K - 1972 Porsche 911T 2.5
Interesting to see/ read, thanks for posting.
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
-
- Nurse, I think I need some assistance
- Posts: 8771
- Joined: Sat Apr 23, 2005 9:08 pm
- Location: Nottingham, UK
Re: EKO181K - 1972 Porsche 911T 2.5
Thanks for sharing Darren
The simple things you see are all complicated
I look pretty young but I'm just backdated yeah
I look pretty young but I'm just backdated yeah
- inaglasshouse
- DDK 1st, 2nd and 3rd for me!
- Posts: 2427
- Joined: Fri Mar 28, 2014 9:35 pm
- Location: Surrey, UK
Re: EKO181K - 1972 Porsche 911T 2.5
Thanks Darren, very interesting. As you said to me recently, I feel your pain!
- Darren65
- Nurse, I think I need some assistance
- Posts: 7873
- Joined: Mon Dec 13, 2010 10:55 pm
- Location: North Wiltshire
- Contact:
Re: EKO181K - 1972 Porsche 911T 2.5
....cheers Richard but such is life and nobody diedinaglasshouse wrote:Thanks Darren, very interesting. As you said to me recently, I feel your pain!
....I was actually reminiscing recently about the last day of our Alps trips just as we were about to drive Klausen Pass; our last pass of the trip before we headed back to Dijon.......the Mongrel had started to sound really quite poorly at idle but was still pulling strong, I really should have called it a day and summoned recovery but it was such a beautiful day.......after another epic run we reached the other side and Feroz consulted his atlas for a route homebound before declaring 'it's probably just as quick to head back the way we came!'.......I beamed from ear to ear and gave a little fist punch, one more pass! .....one more run bouncing off the rev limiter and thrashing the arse off the car once again!.....
.....foolish?, most definitely!......would I do it again?, in an instant!.....those that have driven Klausen would know how I felt, those that have been down that road and don't feel the same have never driven Klausen!
On the right day with good friends on a great road my car would have to melt before I lifted!
Happy days
Darren
72T 2.5... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=56183
73 2.4E ... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=44242
77 Carrera 3.0...to 74 3.0RS ... http://ddk-online.com/phpBB2/viewtopic.php?f=28&t=63389
72T 2.5... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=56183
73 2.4E ... http://ddk-online.com/phpBB2/viewtopic.php?f=10&t=44242
77 Carrera 3.0...to 74 3.0RS ... http://ddk-online.com/phpBB2/viewtopic.php?f=28&t=63389
-
- Nurse, I think I need some assistance
- Posts: 10294
- Joined: Wed Mar 31, 2004 1:27 pm
- Location: Cheshire
- Contact:
Re: EKO181K - 1972 Porsche 911T 2.5
Good rally driver mentality “if it’s not on fire then it’s all good”
Re: EKO181K - 1972 Porsche 911T 2.5
I remember that moment so clearly Darren, that was the best day of driving I ever had. Gutted Rob didn’t make it but was glad you hung in there. Can’t imagine anything topping that.
The force is strong in this one ......
-
- Nurse, I think I need some assistance
- Posts: 8771
- Joined: Sat Apr 23, 2005 9:08 pm
- Location: Nottingham, UK
Re: EKO181K - 1972 Porsche 911T 2.5
Nice
Can't remember if we did Klausen - it's all a wonderful blur
Can't remember if we did Klausen - it's all a wonderful blur
The simple things you see are all complicated
I look pretty young but I'm just backdated yeah
I look pretty young but I'm just backdated yeah
-
- Me and DDK sitting in a tree! KISSING
- Posts: 2585
- Joined: Mon Sep 18, 2006 12:23 am
- Location: Palm Springs, California
- Contact:
Re: EKO181K - 1972 Porsche 911T 2.5
Good f-in God. I check-in for a long overdue update and it's in pieces again!
Still think it's the best engine I've ever driven. The definitive spine tingler.
Still think it's the best engine I've ever driven. The definitive spine tingler.
'68 912
Re: EKO181K - 1972 Porsche 911T 2.5
Klausen was on the first day Mark. If you can’t remember it that well, then we need to do a mother trip to refresh your memorysladey wrote:Nice
Can't remember if we did Klausen - it's all a wonderful blur
72 2.4s
96 993 RS
Series 1 DDK membership card
96 993 RS
Series 1 DDK membership card
-
- Nurse, I think I need some assistance
- Posts: 8771
- Joined: Sat Apr 23, 2005 9:08 pm
- Location: Nottingham, UK
Re: EKO181K - 1972 Porsche 911T 2.5
Was that in the afternoon heading back to the hotel?
The simple things you see are all complicated
I look pretty young but I'm just backdated yeah
I look pretty young but I'm just backdated yeah
Re: EKO181K - 1972 Porsche 911T 2.5
It was the first pass i believe, driving from basel to andermattsladey wrote:Was that in the afternoon heading back to the hotel?
72 2.4s
96 993 RS
Series 1 DDK membership card
96 993 RS
Series 1 DDK membership card