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Discussion Starter · #1 ·
Right. I've managed to get my 99T into a garage - so now i can begin to undertake rebuild number 2 after which i should end up with a decent engine and gearbox!

I'm posting this thread to try and work out what i should actually do! I dont want to spend huge amounts of money but am happy to spend a bit if it means i can get the saab to work as a reliably daily driver for the next 12 months, and it be fun in the mean time.

What i have to work with is (most of!) 2 roughly 150k mile engines.

The one in there now has a cracked head/head gasket problem and slightly knackered looking pistons. The bores looked okay to my eye with the pistons in. Has W.I and looked like it may have been thrashed somewhat (the gearbox is very noisy and the turbo was turned up over 1 bar)

The other engine blew a head gasket about 5 years ago and then sat in a garage with the engine full of mayonaise. Had an elderly owner who probably drove it carefully. Most recently it has sat outside and has got a bit soggy and hence has rust over the surface of the block and in the top of the bores. The top of the pistons look good.

I'm not an engine expert, but i'm trying to improve. Ive rebuilt a nice simple landrover engine before now but this only invloved new standard components and no machining. It looks like im going to have to have some proper work done on this saab one.

My thoughts so far are:

Head
Use head number 2, and get it professionally checked first!
Is it worth getting it very lightly skimmed to prevent any possible futher problems? (as it was in an engine that lost the head gasket too).

I can also get work done on the head at resonable prices by a mates father-in-law who is an engine rebuilder by trade.
Is it worth getting my head ported and polished while its all apart? Will this get me any noticeable improvements?

Is there anything else i should do to it too while its out? I've seen port matching stuff mentioned elsewhere but dont know anything about it. Is stuff like this worth getting done?

I presume that there are valve stem seals in there somewhere too that i could replace?

Block:
The pistons out of engine 2 look better than my existing ones so i could use them. I can put new piston rings on them before i refit them. Ive done this before.

Which ever block i end up using is going to get a new set of main bearing shells in it. Ive also done this before so its no problem. Are there also other shells or bearings on the jackshaft that I should look at/do too?

I'm not sure which block to use. number 2 would be easier as it already out of the car but it has gone fairly rusty and definately needs skimming.
Is it worth getting it bored out very slightly? - Its done 150k miles and is a bit rusty and manky. If i do get it bored out can i use my existing pistons with bigger rings on? or do you need to replace all the pistons too (which sounds expensive and id rather avoid!)
Ive never had any work like this done before, so dont know what to expect!



I have ordered a water pump tool so that i can pull the pumps out and examine them, and replace as necessary (im hoping that one looks good!)

What else is there in there that i should be thinking about?
 

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you should have enough parts to make one good engine.

1. have the pistons and respective block measured for wear and ovality.

2. the 99 turbo head is notorious for being porous, find a later b series head form a 900, the material was a better quality.

3. if you do have the head flowed, i would not have the early head done, in case it starts to fail. To have it gas flowed properly expect to spend £400-500 and this is with standard valves, add another few hundred if you want larger inlet valves. To gas flow a head to it's optimum flow for a specified camshaft it needs to be done on a flow bench.

4. Have the crank checked for journal wear and twisting.

Machine shops normally check components for free or very little, apart from pressure/leak testing heads as this takes a bit more time.You can then purchase parts to match the specified tolerances.
I hope this is a bit clearer as to what to expect?
 

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Discussion Starter · #3 ·
Thanks!

I'm going to use one of the 2 heads i have - I can't really justify buying another one (and i have no storage space left now :( )
I have a H engine 900 head! but that isnt a lot of use for the B engine 99..

I was going to get the head done as a foreigner by the guy, so its a lot cheaper than that!. I hadnt thought about larger valves - but that sounds like it could be a bit expensive anyhow.
Is the only reason you say its not doing on the early head because it might fail anyway for other reasons?
Since i have to use one of my early heads either way, i can live with that risk.



I shall add getting the crank checked to my list of jobs!. Shall probably start pulling apart the spare engine later and see what i find.
 

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Tomarse said:
Thanks!

I'm going to use one of the 2 heads i have - I can't really justify buying another one (and i have no storage space left now :( )
I have a H engine 900 head! but that isnt a lot of use for the B engine 99..

I was going to get the head done as a foreigner by the guy, so its a lot cheaper than that!. I hadnt thought about larger valves - but that sounds like it could be a bit expensive anyhow.
Is the only reason you say its not doing on the early head because it might fail anyway for other reasons?
Since i have to use one of my early heads either way, i can live with that risk.



I shall add getting the crank checked to my list of jobs!. Shall probably start pulling apart the spare engine later and see what i find.

Yes, the only reason is the quality of the material of the early head, as far as i am aware there are no other issues. If you can get the head flowed really cheaply then i suppose it's worth taking that risk.
The other parts i never mentioned to replace are the timing components,tensioner,chain and guides, the sprockets very rarely fail and are usually used again without any problems.
 

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Discussion Starter · #5 ·
Did the sprockets and chain+tensioner on the dodgy engine i have now, so was going to transfer them across!

And sprockets do fail! - I have one with some missing teeth on it. This is one of the reasons why i initially bought the second 99T!
 

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Tomarse said:
Did the sprockets and chain+tensioner on the dodgy engine i have now, so was going to transfer them across!

And sprockets do fail! - I have one with some missing teeth on it. This is one of the reasons why i initially bought the second 99T!
I said 'rarely fail' and sometimes when they have failed it's failed because of the chain/tensioner have been worn out. What was the condition of the chain and tensioner/guides on the one that failed?
 

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Discussion Starter · #7 ·
I wasnt meaning that you were wrong!, i was agreeing!.

I think that the sprocket broke because somebody bodged up an attempt at a head removal. They didnt put the top sprocket on the bracket, and thus lost the tension in the chain when it moved.
It lost so much tension that the tensioner popped all the way out and wedged itself at 90 degrees to where it should have been.
Then they pulled it as tight as they could, refitted the top sprocket and tried to start it.

I reckon thats where they gave up, and i got it as a second hand non-runner that 'needed a new timing chain'..
 
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