Weak points of our engines????
Turbo Mini Forums

Right I?ve just had another rolling road.

I get very nervous of going, as what are the weak points of an A series engine?? After all I don?t really rev it that hard. (6000-6500) ish.

We keep pushing our little cars more and more, how much more can they take.

So apart from the head gasket, which on most cars can be a weak point, and detonation, which could be a killer. I don't mean part fail down to back tune more down to stress.

What parts do you think / have experienced are the weak points and are likely to fail???

MW

Edited by Miniwilliams on 22nd Mar, 2005.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

lost 2 pistons difirent times piston split in 2 right through gudgeon pin using 8500rpm wrecking every thing apart from cylinder head, never found con rod only had top of the piston left

my bank balance is my weak point

Team Racing

on turbo A series my own experience are Mat.

head gaskets due to Detonation.

also the head falling of an exaust valve
NONE sodium type it was 214N Race valve

the standard diff pin

gear chippings wedging the pressure release valve open

the idler gear excessive wearing the clutch case

thrust washers due to heavy clutches needed for the high torque

Team Racing

Matt - WTF are you asking this???



I'd have thought you'd know more thn most!!!

Dave and Jon, i wouldn't be posting this if i know the answer now would i, by the look of things nor does any one else:(

So I guess i'm on my own then, lol.

I just wondered what i needed to keep my eyes on next. What about conrods do we know what power they can take up to??

i think in the main, i'm finding it hard to see how a very old design of engine and box, keeps taking more and more.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

Fair enuf Matt!
What I will add, is that if RPM's are kept to what you're keeping, rods, rod bolts, pistons, won't be an issue.

I think a steel 4-bolt main cap might start to feature in a spec list for 'peace of mind' sake - maybe even the other caps aswell?

I'd get the crank Magnafluxed EVERY time it came out (crack detection) for a rebuild or whatever.

Always run caphead bolts (high tensile) between the engine and tranny - maybe add more?


The Tranny is the point where most effort should be placed. If you want to make more power whilst keeping to the same rev-band, then this is coming from a torque increase - nowhere else...

I'd be pressure feeding the Idler bearings, or using the 'fully supported' type of s/c idler gear.
I'd also pressure-fed the laygear bearings - again, just peace of mind.

Always add at least one additional magnet into your gearbox... Jim has a picture of what I installed into his transmission...

Something else I'd like to see introduced to the market is an overdriven idler set - where the 1st motion gear turns faster than the primary gear. The torque inside the 'box would drop by the same percentage as the ratio increase...

What else can you do? Fook knows! Build it properly?

"Something else I'd like to see introduced to the market is an overdriven idler set - where the 1st motion gear turns faster than the primary gear. The torque inside the 'box would drop by the same percentage as the ratio increase... "

Ages ago I did some ringing round but no one did an over drive set, I was surprised then and I still am now that no one has taken the initive!

A;ex

AlexF

Thanks to every one that have posted.

Now Dave That?s more like it:)

I like the idea of different centre and other caps:) That's a real piece of mine one.
I've copied the post for future looking into.


"Build it properly? " You cheeky f_cker! I'm only a carpenter you know! :)

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

LOL! It wasn't aimed at you - just a general comment!

No your right though lol

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

i as wonderignt his too as i want my car for every day use and thatss hwy i am keeping the power down to about 120bhp so it doesent need rebuilding every year. so how many miles should it really take with every day driving and the odd weekend at york?
and do the standard rod bolts hold ok o are ARP generally considerd worth the money?
sorry for hi-jacking matt!

thanks, Dan

Standard rods and bolts are very good items, as we dont need alot of revs to get power they will be fine. If you look after your engine with gegular oil changes etc, 120bhp should last many thousands of miles.(hard to say exact mind)

-MINI CLUBMAN 1380 TURBO-

you ought to get it setup once a year thou....

remember 5 second lean on high boost and its bye bye pistons!

alex

AlexF

Dan as T3 said 120 bhp should last a while. As for the standard rods and bolts, in most cases you can't bet geniune stuff. i have had standard rods for years. Arp bolts are not needed for what you said you are after.

Alex is right as for engine life it needs to be keeped in top tune, i get mine checked a min of 4 - 6 times a year though this might be a little much, but i does let you know early if your having probems, and could catch a costly problem later on.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

i will deffo get it set up enough times and get freindly with the RRs:)
also will be using air/fuel meter and lambda for peice of mind.
good news for me that the standard internals are happy with that for lots of miles i am impressed

thanks! Dan

good idea about the getting some sort of gauge, i would be going for a exhaust gas temp gauge rather then an air fuel gauge, but thats just me.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

afr tells you egt in a rough kinda way!

you run lean and cause damage before most egt gauges react

alex

Edited by AlexF2003 on 24th Mar, 2005.

AlexF

yor right the word is MOST gauges

not sure if any gauge will help like that if you have a big lean out as it so fast.

Edited by Miniwilliams on 25th Mar, 2005.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

The question which I often wonder with an O/D idler, where does the torque load go? I reckon that the idler bearings would get more cained.

Intersting point about the thrust washers. I hadn't thought about that.

Every gearbox I have taken to bits has had worn mainshaft bearings in varying degrees. I wonder if this is due in part to side thrusts and what size those side thrusts are. With super torque engines pulling a serious load, the side thrusts on (very helical) CWP's must be considerable. I haven't got one to look at now but can't figure if the pinion and input gear are helically "additive" or self cancelling.

Bugger off, I'm getting there.

i see what you mean about a/f ratio guages now i am a little more worried but i still want one lol
what does exhoust gas temp tell me? i mean i know it tels me how hot the gas is but what difference does it make to me?

thanks, Dan

lean mixture equals hotter gas...........