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Overheated engine rebuild (Upgrade Options?)
Posted: 22 Jan 2012, 20:46
by Zomerzet
I'm awaiting delivery of my first T25 later this week with a 'dead engine'. I've had a 1302 bug in the past and am happy stripping an engine but I'm after some type specific advice
Firstly, the engine has apparently been run to death with a blocked/crapped up oil cooler and overheated. The oil has been drained out and it had metal bits in. I believe the piston ring on no.3 was fragmented but still in place. It's a 2.0l Aircooled CU I think.
1- Right firstly, will this scrap an engine completely
2- I am planning on dropping it out and stripping it to see the damage, check pistons, rings, bores and crank bearings. Anywhere else that may need examination
3- Whilst the engine's out and in bits are there any service items its a good idea to replace
4- Are there any 'Gotchas' or catches I need to be aware of on an Aircooled engine (I'm used to A-series minis!)
5- It's fitted with a single carb, but I'm unsure of VW carb types just yet. It's new but any good

6- Are there any worthwhile 'upgrades' like cam/balancing/porting (What exhaust would be beneficial considering the carb (Hopefully) upgrade?):?:
Sorry about all the questions but I need to keep myself going until it gets delivered somehow!
Re: Overheated engine rebuild (Upgrade Options)
Posted: 22 Jan 2012, 21:27
by California Dreamin
The world is your oyster and although more work than you were initially looking at doing this maybe a perfect time to carry out a diesel transplant.
A cheap option might be a normally aspirated 1Y (1.9D) ...lots out there and reasonable money, unfortunately you would need another gearbox as well.
2litre CU's are lovely but very thirsty and a little underpowered.
17 - 21mpg for a CU
30 - 40mpg for a 1Y
Martin
Re: Overheated engine rebuild (Upgrade Options)
Posted: 22 Jan 2012, 22:03
by billy739
converting an Aircooled to a diesel is not that easy , especially for a novice
stick with the Aircooled , but price it all up and make sure you can get ALL the parts before ordering anything.
strip it it may not be that bad but otherwise,
easiest is to buy a good used motor, around 500£- remember you can sell yours and get a good return
keep the standard carbs and make sure all the cooling /seals are good and you are all done.
Re: Overheated engine rebuild (Upgrade Options?)
Posted: 23 Jan 2012, 08:46
by Zomerzet
Yeah, I like the idea of diesel, but for the cost and hassle of getting one together, I could probably get a second hand LPG kit. If I was going to go for a different engine, I would probably look into a Subaru conversion if anything. I just need mine running for now.
Is it worthwhile putting a hotter cam in at all? Anything to improve the torque on such a heavy vehicle. I've heard the standard carbs can be crappy which is why I'm pleased my van has switched to a single (Easier to set up too). Would I be right in thinking this may improve economy, abeit slightly? Once I sort an engine, I always take it to get tuned properly which pretty much always make sure everything's running in tip top efficiency. I know I'm not going to get supercar performance with the Wedge, but having a good bit of grunt must help up the hills
I've stripped engines before on minis and the Aircooled lump is so basic it's not going to be THAT difficult surely? I just want some sneaky hints that anyone might have for a good build

Re: Overheated engine rebuild (Upgrade Options?)
Posted: 23 Jan 2012, 09:37
by ghost123uk
I am not an Aircooled expert but I did help a friend re-build his with new barrels and pistons and it was a doddle compared to re-building the watercooled version (which I have done to some extent more than once

) If you are OK with other engines then this won't phase you. Just use good quality parts (Brickerks do only the best quality parts and their service is 1st rate) and follow usual "best practices")
The 2Ltr CU whilst rather thirsty is not too bad power wise.
Others will be along soon no doubt to talk about cams, porting and such.
A guy named Laurie Petit is famed for making very strong Aircooled motors. See =
http://lauriepettit.co.uk/" onclick="window.open(this.href);return false;
Re: Overheated engine rebuild (Upgrade Options?)
Posted: 23 Jan 2012, 13:25
by kevtherev
The best and most cost effective way of increasing engine power to the Cu 2.0 L significantly enough to notice ..and put a huge grin on your face are a set of Dellorto DRLA 36 carburettors,
These allow the engine to breath in better, couple that with a set of nice new stainless tubes, you'll be laughing your head off at hills.
economy would be the same unless you just cant resist dropping the foot for some fun with traffic.
economy and power is a Holy grail often sought but never found

Re: Overheated engine rebuild (Upgrade Options?)
Posted: 24 Jan 2012, 12:54
by Zomerzet
Thanks Kev, that's the kind of advice I'm after. Yeah, I know about the compromise! I just want to make sure the engine is working as efficiently as possible. If there are any areas such as the carbs where there's a 'bottleneck' preventing good airflow, I want to make sure I've made the best of the restriction. Are there any good free flow exhausts you'd reccommend, as the engine's induction is good, but it's not going to be maximised with a stifling standard exhaust
I've got a singe Weber on there at the moment, which should be a pretty good upgrade, compared to the standard things
How do twin Webers compare to twin Dellortos (I had twin Dellortos on my Bug and they seemed pretty good, but never had anything else fitted)
I've not actually driven a T25 yet, as this'll be my first one. I just want to make sure, whilst the engine's out that I don't miss an opportunity to install something that means engine out again. Just glad I've got the 2l Aircooled with easy pushrod tubes! I'm interested to get to grips with hydraulic pushrods too, so a whole lot of learning to look forward to.

Re: Overheated engine rebuild (Upgrade Options?)
Posted: 24 Jan 2012, 13:15
by kevtherev
Delorto..any thing else is just not Delorto.
My friend JasonK will spot this soon and put his vast knowledge of dells to you.
Any stainless exhaust J tube type is good to go.
Turbo Thomas is one fella, there are loads of others. just search
stainless exhaust
Cruz has put something in the wiki and a post here about exhausts..again very informative
exhausts should be "staight out an empty" but there are noise laws
while the engines out you might want to change various seals (fly and pulley)
oil pump, renovate the tin and tidy the engine bay up.
Re: Overheated engine rebuild (Upgrade Options?)
Posted: 24 Jan 2012, 16:08
by faggie
for any decent performance upgrade your better upping the cc to 2400cc and replace the centre mounted carb as they are troublesome due to the long intake manifolds giving poor running flat spots etc this carb will give you less performance than the standard solexes its better to replace with a pair of 40 webbers or dellorto carbs , as for exhausts anything from bas you cant go far wrong , dont bother with the cheap empi exhausts seen at shows they only last around a year and are very cheaply made
Re: Overheated engine rebuild (Upgrade Options?)
Posted: 24 Jan 2012, 18:33
by jason k
that single weber is effectively strangling the motor, chuck it in the bin where it belongs.
the inlet tract is waaayyy too big and is liable to icing in cold weather
as my mate kev says, bang a pair 36 or 40mm delortos on and you really wont regret it.
a good torque cam is beneficial as is a set of 2.1 pistons and pots if you dont want to split the case
or machine heads to fit 2400 pots
Re: Overheated engine rebuild (Upgrade Options?)
Posted: 24 Jan 2012, 18:34
by jason k
as faggie says avoid empi stuff, i prove on the dyno it actually robbed power over the stock box.