Oversize 911 pistons

Gary71 · Post by **Gary71** » Tue Jan 02, 2007 1:51 pm

I'm currently contemplating (i.e suffering heart failure adding the cost up) an engine rebuild.

As I have a good old 2. 4 Mint T it has cast iron barrels, and so can be rebored by traditional methods. However where can I get a set of matching overbore (+1mm?) cast ali pistons for sensible money?

Any thoughts?

davidppp · Post by **davidppp** » Tue Jan 02, 2007 5:02 pm

Hello Gary.

I can help here: Pm'd you.

Kind regards
David

Alan @ CanfordClassics · Tue Jan 02, 2007 11:33 pm

Hi Gary,

read this, it will help.

Alan

http://forums.pelicanparts.com/showthre ... light=85mm

davidppp · Post by **davidppp** » Wed Jan 03, 2007 10:59 am

Hello, Gary.

I'd strongly recokmend saving up to do it right..with new parts as much as possible..the time and cost involved in just stripping and rebuilding is a very large investemnt, even if you do it yourself.

So I'd target as a minimum, new valve guides, new or excellent used valves, new high-comp pistons, and the bearings and chains.

I'd not bother with hydraulic tensioners, just make a pair of screw-type mecanical tensioners, and ideally put bushes into the idler arms.

Now, to make this a really really nice engine, just pop in a pair of E cams..this is a truely amazing road engine, with serious torque from 2500 to 7000 rpm, and an almost flat curve..

With a little luck and effort this will cost you well under £2000 in parts, without cutting too many corners.

With lots of luck, much less..

You can put 32mm, or even 34mm chokes and approprate jetcs into the Zeniths of course..!

And for a little more, open the inlet ports up..

Kind regards
David

Gary71 · Post by **Gary71** » Thu Jan 04, 2007 1:17 pm

Thanks David, Alan, and Chris (via pm

)

My provisional costing for a basic rebuild with all the bearings, valve guides, gaskets, chains etc has come in at £690 in parts (based on Pelican, a decent exchange rate and a customs bypass route

). This makes the (admittedly significant) assumption that the original valves, pistons and barrels are servicable.

Reusing original barrels, but rebored/honed and with new forged 85mm pistons adds around £1000 on top of that.

Adding the E cams (assuming I can find some) and a new set of rockers adds another £700ish based on Mittelmotor used cam pricing.

All in all one big ouch. So David how do I get it under £2000?

Oh and I only have about £500 to do it all with

davidppp · Post by **davidppp** » Thu Jan 04, 2007 7:03 pm

Hello, Gary.

I have some cams..if the rockers are ok, I'd reuse them..so assuming we can sort you some nice pistons at the right price...

Are you in a hurrY?

Kind regards
David

stuby · Post by **stuby** » Thu Jan 04, 2007 7:50 pm

Gary
Have pm'd you a contact no. for a good friend of mine who I am sure can sort you out with a lot of things you need at the right price - certainly helped me no end on my engine rebuild

Stu

Gary71 · Post by **Gary71** » Thu Jan 04, 2007 9:04 pm

Cheers David and Stu,

I've come to the conclusions that any rebuild plans are just that at the moment unfortunately. There is no way I can afford to do it properly, so I not going to do it at all at the moment. 5 1/2 cylinders and regular de-oiling of the plugs will see me through for some time to come.

I've just got to try and forget those compression figures

I am going to treat it to a set of Magnecore 8.5mm HT leads made to fit my Ford EDIS coil pack one end and Porsche on the other. With my DDK discount these are around £125, so good money by any measure. At least this will ensure I'm making the most of the spark and not losing some of it on the way!

Many thanks for the contributions and I'm sure I revisit this again once it does finally stop running completely.

Ian Donkin · Post by **Ian Donkin** » Thu Jan 04, 2007 10:08 pm

Gary

Exchange Cams (custom ground) from DR Camshafts in the US and new / refurbished rockers cost me around £200 all in last year IIRC - I go out there on the 16th for enough time to get them turned around whilst I'm there if you want...

I bought used / good 2.2E B+P's from Jim Avis for £300 and my head work for valves / seats and guides is from memory going to cost me £136 all in (not so far from you either)

.

As a final offer of assistance, I have a full set of 2.4T pistons that may yield you a good one or two - you are welcome to cast your eye over them if this helps.

Let me know if any of this is of use.

Cheers
Ian

Gary71 · Post by **Gary71** » Fri Jan 05, 2007 7:55 am

Cheers Ian, More good stuff

I took it out for a 'Italian tune' last night after cleaning the plugs and it felt much improved. However I backed it out of the cold garage this morning and it stalled (no surprise there), and then just clicked when I went for the traditional second start. Great... of course it stalled with the drivers door just next to the door frame so I couldn't get out. I have an interview this morning (in about 20 minutes) Is this a good omen

Guess I be checking my earths tonight as the batteries are fine. *sigh*

Ian Donkin · Post by **Ian Donkin** » Fri Jan 05, 2007 3:54 pm

Question is, did you get the job?

Gary71 · Post by **Gary71** » Fri Jan 05, 2007 5:15 pm

Find out next week.....

Ian Donkin · Post by **Ian Donkin** » Thu Jan 11, 2007 2:09 pm

And....

Gary71 · Post by **Gary71** » Thu Jan 11, 2007 2:19 pm

It is mine

Ian Donkin · Post by **Ian Donkin** » Thu Jan 11, 2007 2:47 pm