In the process of a rebuild due to bearing failure and Ive been told that I should replace it because it will have bits of metal in it. Ive also been told I can clean it out thoroughly and reuse it.

Is there a definative answer ?

Obviously if money was no question then I would, but funds are tight and if its not critical to replace and can definately be cleaned then Id rather do that.

yes i would, for the price of the modine in comparison to the price for a engine rebuild its false economy change it not to change it.

Definitive answer is you can never completely clear the debris, it is not that expensive an item either so be on the safe side and replace it.

Banny

How cheap are people selling them for then because Ive seen them for £140 which aint really that cheap ??

£140 is very cheap compared to a rebuild :)

I can appreciate that but is there no way it can be cleaned out with an airline and brake cleaner ? My bearing didnt shatter and there wasnt a load of metal in the sump or on the filter gauze

bump

Try Subaru Impreza Turbo Parts, Tuning, Spares & Accessories - (http://www.camskill.co.uk/products.php?plid=m10b0s0p0)

Deffo replace it...:thumb:

I have been told by an old skool enginer that they can be striped down and cleaned, and then while its appart you can check the tollences with a feeler gauge before rebuilding it.

I have been told by an old skool enginer that they can be striped down and cleaned, and then while its appart you can check the tollences with a feeler gauge before rebuilding it.


I think he's refering to the oil pump

Yes the pump you can strip down, check and rebuild, but not the modine. I had the same dilemma; the opinion on SN has always been to replace the modine as a matter of course, which I can understand as it's not rebuildable and there are a lot of places in there that could get swarf stuck in. But where I disagree is when people say they are 'cheap'. They are not, IMHO. Let's put this in perspective - I could buy an entire car for £140 or whatever the current price is (cheapest that I can find is Alyn at AS Performance - PM 'Stockcar' to get his prices). They are not even cheap compared to the cost of a rebuild. You could easily do a bog standard rebuild for under a grand if you're doing it yourself so no, I don't think spending 15% of your budget on one simple component that may need replacing is good value.

I agree that it's something that most likely has to be done if there is any chance of there being swarf in there, but it's not cheap. It should be factored in as a major part of the cost of a rebuild.

I was expecting silent running to reply :). I agree with what you say, my crank and rod machine work, oversize bearings, piston rings and gasket sets cost me £570 and I thought it was worth changing the oil pump to the modified version for £150. So adding another £140 is relatively quite expensive for something that has a possibility of being re-used.

Did you regrind the crank?

That is a no- no

Yeah I had it ground but it was well within tolerances, needed 4thou off and they can apparently go to a lot more respectivly speaking, cant remember the exact amount.

Surely the machinist company would have said if it was unsafe to grind ?. Both the guy doing the work and a friend who works for Subaru said it was OK to grind but had lower tolerances than other marks.

Those companies who have being doing subaru engines for many years, don't advocate grinding the crank, as the hardened surface is very thin on the bearing surface. Grinding removes this.

Oh dear, I think you would be wise to buy a new crank or else you might end up with another rebuild job in a few miles.

I would speak to David at Api, they build many Impreza engines a week.

Surely my friend at Subaru would know this tho ? He has been working on them for many years !

Surely my friend at Subaru would know this tho ? He has been working on them for many years !

I hear what you are saying, but if you do a search, then you will see lots of threads, that say you must not re grind an Impreza crank.

For an impartial chat ring Api, then Zen, then Roger Clark, then Scoobyclinic etc etc. You will be told the same by all of them.

Surely my friend at Subaru would know this tho ? He has been working on them for many years !


No disrespect to your friend but if he is a Subaru Technician,how many engine builds has he actually done as opposed to the normal scheduled servicing,warranty work,car prep etc etc.
Speak to the likes of API,ZEN etc who employ engine builders to build engines.

Im not trying to prove people wrong or anything and the whole reason for this post and indeed, forum, is the sharing of info to everyones gain.

However, there seems to be many different points on this.

1. API - They say not to do it because swarf could still be in the crank oilways and will then ruin the new bearing, not because of any hardening process on the crank.

2. ScoobyClinic - They say as long as oversized bearings are used it shouldnt be a problem.

3. Zen - They have never and will never use a crank grind

4. Roger Clark - Say the same as Zen.

5. Local Subaru Dealer - They send many cranks to be ground (co-incidentally to the same machinist who has done mine).

So as you can see, it doesnt seem to be so cut and dry !!

Like I said Im not trying to argue with people Im just trying to do a build without having to spend more than I need as Im sure you can understand.

Now Im not saying its the case but its a 'possibility' that specialist companies who say to never grind a crank and always use a new crank are at the end of the day getting more money for doing it that way. Not accusing anyone of doing that, I could be wrong but its a point to consider.

As I wrote API said that you cant re-use it because a crank cant be cleaned out because of the shot-peened ball bearings in it, but as far as can be seen this is no different to any other crank and an air line and cleaner should be able to clean it out.

My friend at Subaru has rebuilt many engines and some that have had grinds, not trying to prove a point but he does a lot more than just servicing and has done for many years.

Any thoughts on these comments would be much appreciated

Sounds a fair assessment to me.

thought subaru never replaced just cranks in engines as its more cost effective to use a full new built short engine?thats what they said about my friends old p1 when it went knock knock a few years ago

p1 engines are different to standard turbo engines when it comes to ordering them from subaru. if it's a standard turbo engine then it's discounted quite a bit almost like subaru know there is a problem with them but a p1 engine gets hardly any discount for some reason.

and as a scooby tech i have built more engines than i care to count now and i always use a new crank

So has anyone on here had a rebuild and used a ground crank ?

Not me. But only because to my way of thinking, the cost of a regrind is not (proportionally) much less than a new one, plus second hand ones can be had for under a hundred quid. All you have to do is measure them up to check they are in spec, and bob's your uncle. They don't really wear apart from if they've had bearing problems.

Well, cheapest Ive found a new crank is £495 and Im not sure if a 2nd hand one could be guaranteed any better than my one. My grind only cost me £40 so as long as we can clean it out, which I cant see why not then as long as its OK im definately better off !

i got a new v9 cross drilled crank off flea bay for 530 including both sets of bearings and delivery, i thought that was well worth it.

Thats a good price but still not as cheap as a £40 grind !

dont buy a subaru expecting anything to be cheap..... the way ive learned is if its to cheap to be true it usually is ..... everthread ive read about regrinds has been a no. People can only voice there opinin if it works fair play for £40.00 but if it doesnt its a big told you so.

dont buy a subaru expecting anything to be cheap..... the way ive learned is if its to cheap to be true it usually is ..... everthread ive read about regrinds has been a no. People can only voice there opinin if it works fair play for £40.00 but if it doesnt its a big told you so.


I hear what your saying but this isnt my first performance car, having owned a GT4, S2000, RX7, MR2 Turbo I know how expensive fast jap cars are, but no-one seems to be able to give me a definative confirmation of why you cant use a grind.

Also if no-one has used a grind how do you know it doesnt work ?