2.4T engine rebuild - Shock: It actually runs!

[Gary71]

All, The time has come to accept that the clouds of smoke on starting and lift off, together with various ticks from the cams, puddles all over the floor and misfires are telling me that I really need to pull the lump apart and refresh it, at least the top end anyway.

Although I've owned the car for 13 years and driven many, many hard miles I've never had the engine apart except for doing the timing chains and ramps a few years back. I have no idea of the overall mileage or previous rebuild history, but routine maintenance has been thorough in my time with the car anyway!

As far as I know the engine is stock throughout, apart from turbo rocker covers, retaining Zeniths, iron cylinders & 3/4R mag case, and is matching numbers to the car.

So...

Of course I want more power

...don't want to spend a fortune.

...plan to do it all myself (less any machining required)

...don't want to lose the flexibility of the T, but another 500rpm on top wouldn't go amiss!

...don't really want to split the case, as oil pressure is good and the £££ can go north very fast if I go there.

Thoughts so far: Alternative opinions and advice welcome from those that know!

- Slight overbore to refresh the cylinders
- Higher compression pistons: Maybe J.E 9 or 9.5:1 rather than 7.5:1 as standard - Recommendations?
- Light porting of heads
- New guides
- Recut valves
- Refaced heads
- E cams, these seem to be the profile of choice for a sensible road engine - Anyone have some spares?!

Whilst I'd love everything super shiny and fresh I'm realistic about the budget and my car is a driver, so it's more about the internals than plating and polishing the outside.

Thoughts and advice more than welcome

[Gary71]

P.S Anyone have a 911 engine stand I can borrow?

[impmad2000]

My engine stand is with Sladey, you are welcome to use that.
I was going to 2.2S p&b with E ish cams. But my plans are firmly on hold for now, and the 2.2 T is going nicely anyway

[911hillclimber]

My 911 had a 2.4 E on mech inj and S p&b.
Those cams are a dream.

I think your spec list is bang-on but I would take it down to the crank so fixing any case leaks.
Chose your machinist carefully, I have a horror story and a happy ending story for you.

Finally, have a read of Dempsey's book and Andersons guide of course.

ps
Price of an engine stand is nothing compared to what you are about to spend...

[bjmullan]

Gary I just hope you don't take as long as I did!

You may want to split the case as has already been said and you can then do the oil bypass mod to your case. As for your cam's you could consider getting your T's reprofiled. My cam's have an Elgin E stamp on them.

Good luck.

[abzadams]

I'm about 12 months into my build and its been an absolute nightmare, but I can pass on some advice. Its only with the help of a kind DDKer and his contacts that I am nearing completion.

The first question is do you need to rebuild? Can you pull your engine and pop a bigger one in, if more power is your aim? If you ever come to sell the car at least you could pull the engine back out and sell it separately, whilst if you rebuild the original engine then the the money is all into it, so to speak.

If you decide to rebuild your spec sounds good, as you are on carbs your heads are already 32/32 unlike my 29/32 on my MFI T. These are the same as an E, so I'd go with the E cam. Its not what I ended up doing but it was what I was thinking. I was limited by my MFI, to a certain extent.

Here is a good link to an alternative spec, 2.2T pistons are cheap and you could get the pockets machined for a couple of quid, so it may be cheaper than a new set of JE's.

http://forums.pelicanparts.com/porsche- ... s-mfi.html

I always thought the above engine sounded great and is often talked about on Pelican, and would be a reasonable build, especially with carbs.

As Brendan said, the oil by pass is a good idea for longevity, PM me for costs if you decide to do this.

Cams, I had a quote of £200+VAT to regrind my T cams to E, these were from Newman cams in Kent, they would also resurface your rockers if need be.

Lastly there is a good post on Impact bumpers about the parts needed for a top end build, yes its for a 3.2 but still an eye opener,
http://www.impactbumpers.com/forum/inde ... ild/page-8

Hope that helps, give me a shout if you want to talk about anything.

R

[Gary71]

My engine stand is with Sladey, you are welcome to use that.

Thanks Tim, I'll give him a shout once I'm ready to start (no desperate rush!)

Chose your machinist carefully, I have a horror story and a happy ending story for you.

Thanks Graham, Can you PM the happy ending, and the horror as I guess it's not for public consumption

Gary I just hope you don't take as long as I did!

That's not going to happen! Once I start something it tends to get done

I'm about 12 months into my build and its been an absolute nightmare, but I can pass on some advice. Its only with the help of a kind DDKer and his contacts that I am nearing completion.

Thanks Rich, again if you don't mind please PM the nightmare and the good stuff

The first question is do you need to rebuild?

Well, it's still running well enough and pulls ok at the top, but the smoke is getting beyond a joke. I thought about an engine swap (much like GavP did having read his post again recently) but I might just end up with another more powerful smoky engine... More power isn't my ultimate goal, but whilst I'm throwing money at it I may as well use parts that give me more.

Cams, I had a quote of £200+VAT to regrind my T cams to E, these were from Newman cams in Kent, they would also resurface your rockers if need be.

Sounds a good contact. Thanks.


It always interests me that whenever there is talk about rebuilds the word 'nightmare' or 'it took the machine shop 6 months then I had to take it somewhere else' etc come up. Is there a way to do a 911 rebuild without just giving it to a one stop shop and parting with 20k for it to come back shiny?

I'm not scared of spanners, know my way around an engine and could even use the mill to do the machining if I had one. It can't be that hard. Can it?

[Gary71]

Lastly there is a good post on Impact bumpers about the parts needed for a top end build, yes its for a 3.2 but still an eye opener,
http://www.impactbumpers.com/forum/inde ... ild/page-8

Good thread. Maybe I'll ask him to rebuild it for me!

[jb]

I have heard many sad stories about engine rebuilds and their cost.
If it was me I would take the heads off and get the valve guides redone and the heads cleaned up by someone like the guru of the lakes.
I would then put it back together and check it out.
The smoke would surely be better on the overrun if nowhere else.
I would also have a concerted attempt to discover where the oil leaks are coming from by looking at all the usual suspects and addressing each in turn.
Because you are able to do basic spanner work like removing and installing the engine yourself and dismantling and reassembling it you are not so committed to giving it all to someone else to do so if you have to do it a couple of times unnecessarily it is not such a problem for you. At least you would be able to know that you only did what was really necessary rather than building a new engine up.
Of course if you have plenty of money go ahead!

[911hillclimber]

Gary:
My nightmare revolved around a top names inability to ream new valve guides to allow new valves to be installed and the new seats faced to suit the valves. Morris minor technology.

It went deeper than that and a fair amount of ££££ too.

The happy ending was Mike Bainbridge sorted their work out, minimum fuss, minimum bother and only a little money that seemed great value for the cost.

I ground the seats in within about 5 mins or less, on 3 heads that had been done by the Big Name.

sure I won't name them on here, but I learnt that MB Eng are totally competent to machine correctly and accurately.

The lakes are quite close to you too!
I've rebuilt 911 engines 5 times now, you know they are readily done DIY, you will be done by Xmas.

One thing, go to type911 web site and 'buy' all the parts you need, it really is scary how the bill mounts up and then add packing (in a shoe-box) and VAT..
Dempsey's book is fail-proof and talks about tuning mods too.

Oh, and we want a picture heavy thread.

[Gary71]

If it was me I would take the heads off and get the valve guides redone and the heads cleaned up by someone like the guru of the lakes.

This sounds like the best plan to date!

Gary:
My nightmare revolved around a top names inability to ream new valve guides

What? I was planning to do that myself. This really isn't rocket science is it!

happy ending was Mike Bainbridge

There is a familiar pattern emerging.

go to type911 web site and 'buy' all the parts you need

I did that last night. I had to stop about halfway. Hence JB's plan sounds good!

[911hillclimber]

With the heads off you will see the bores and is any honing is left.
Maybe just fresh rings if the bores measure up ok?

Guess who can measure the bores? that MB bloke, has new premises coming together too.

Rings are cheap and the work is fiddly to do (need the right compressor).

I would still go down to the crank. Very satisfying doing the whole engine.

I think a high-end pro just does the lot as it is the assured way to cover everything off, but some of the numbers stated recently are silly.

[Gary71]

Thanks. Plan is to take it apart down to the cylinders measure everything (I can do this at work) and work out the next step. However I do have to decorate the kitchen before I start...

[911hillclimber]

I think I'm heading for the same situation...
Finished by the New Year then!

[AndrewSlater]

Apologies if this is a dumb question, but what are you planning to use to measure the cylinder bores and to what accuracy does the measuring tool need to be to ascertain whether the bores are good or not?

I'm guessing you need access to a good bore gauge - but how good?

The reason I ask is that I am also stripping down my engine and I also need to check the cylinder bores.
In my case I think the cylinders are standard 2.7 Nikasils.

Any suggestions appreciated.
Andrew