JapCarForum Cars, Cars, Cars! Project Cars Subaru Impreza build thread...

Subaru Impreza build thread...

Subaru Impreza build thread...

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Shaun TDI
Junior Member
48
07-09-2018, 03:21 AM
#1
OK guys.

I thought I'd start a build thread for my Impreza

Most of this information is going to be copied and pasted from an existing blog I've been running for quite some time on another forum so don't get confused if the dates don't quite match up. Feel free to ask questions as we go along.

It starts with the purchase of a nice clean motor.

[Image: 8126_147508571548_664806548_3158361_7673524_n.jpg]

Technically, I couldn't afford it but at the price it was offered to me, I couldn't afford not to either.
Book value on the car at the time was about £5,000 including the mods. I picked it up for rather agreeable £2,500 as a quick sale was needed. Bonza!

Just to recap, late summer 2 years ago saw me remove my gearbox after a gear selection failure.
The only reason for rebuilding the engine is so that it had done just over 100,000 miles.
There was nothing wrong with it - it didn't smoke, wasn't rattling and had no knocks or bangs. I simply had the money to spare at the time.

[Image: Subaru1.jpg]

[Image: Subaru3.jpg]

With the engine removed, I was ready to begin the long and very tedious process of stripping it down and making notes of where everything goes. Since it would be me rebuilding it, it wanted to make sure that i didnt shoot myself in the foot by not being thorough enough.
This will be the first Subaru engine that I've ever built, althought i've built a few volkswagen beetle engines in the past - trust me when i say there are no similarities between them.

[Image: Subaru20A204.jpg]
Shaun TDI
07-09-2018, 03:21 AM #1

OK guys.

I thought I'd start a build thread for my Impreza

Most of this information is going to be copied and pasted from an existing blog I've been running for quite some time on another forum so don't get confused if the dates don't quite match up. Feel free to ask questions as we go along.

It starts with the purchase of a nice clean motor.

[Image: 8126_147508571548_664806548_3158361_7673524_n.jpg]

Technically, I couldn't afford it but at the price it was offered to me, I couldn't afford not to either.
Book value on the car at the time was about £5,000 including the mods. I picked it up for rather agreeable £2,500 as a quick sale was needed. Bonza!

Just to recap, late summer 2 years ago saw me remove my gearbox after a gear selection failure.
The only reason for rebuilding the engine is so that it had done just over 100,000 miles.
There was nothing wrong with it - it didn't smoke, wasn't rattling and had no knocks or bangs. I simply had the money to spare at the time.

[Image: Subaru1.jpg]

[Image: Subaru3.jpg]

With the engine removed, I was ready to begin the long and very tedious process of stripping it down and making notes of where everything goes. Since it would be me rebuilding it, it wanted to make sure that i didnt shoot myself in the foot by not being thorough enough.
This will be the first Subaru engine that I've ever built, althought i've built a few volkswagen beetle engines in the past - trust me when i say there are no similarities between them.

[Image: Subaru20A204.jpg]

Shaun TDI
Junior Member
48
07-09-2018, 03:22 AM
#2
I never quite realized how much stuff there is hanging off an engine. Its also very small once its all been removed.

[Image: Picture025.jpg]

By this point, i'd developed quite a shopping list of standard parts that would need to be replaced due to breakages or general wear and tear.

[Image: Picture039.jpg]

Both of these bakolite breather cover had fractures on them and had sealant all over them. This makes me think that someone may have had this engine apart before.
Once the cylinder heads had been removed, they didnt look too bad. Plenty of carbon build-up but nothing that i wouldnt expect to see on and engine with this kind of mileage.

[Image: Picture045.jpg]

The heads will be fully stripped down and fully flushed to ensure that they're in tip top condition. All new collets, retainers, valve spring seats etc...

The cylinder heads turn out to be very healthy - no scoring or marking on the camshaft journals, no broken springs, no broken bolts or studs - all good!

[Image: Picture050.jpg]

[Image: Picture048.jpg]

The short block is now ready to be split and the condition of the internals revealed.

[Image: Picture041.jpg]

With the pistons removed, block halves split and connecting rods and crankshaft pulled out, all is revealed.
The thing I was most pleased about was the piston crowns. No signs of detonation at all. A testament to my mapper!

[Image: Picture051.jpg]
Shaun TDI
07-09-2018, 03:22 AM #2

I never quite realized how much stuff there is hanging off an engine. Its also very small once its all been removed.

[Image: Picture025.jpg]

By this point, i'd developed quite a shopping list of standard parts that would need to be replaced due to breakages or general wear and tear.

[Image: Picture039.jpg]

Both of these bakolite breather cover had fractures on them and had sealant all over them. This makes me think that someone may have had this engine apart before.
Once the cylinder heads had been removed, they didnt look too bad. Plenty of carbon build-up but nothing that i wouldnt expect to see on and engine with this kind of mileage.

[Image: Picture045.jpg]

The heads will be fully stripped down and fully flushed to ensure that they're in tip top condition. All new collets, retainers, valve spring seats etc...

The cylinder heads turn out to be very healthy - no scoring or marking on the camshaft journals, no broken springs, no broken bolts or studs - all good!

[Image: Picture050.jpg]

[Image: Picture048.jpg]

The short block is now ready to be split and the condition of the internals revealed.

[Image: Picture041.jpg]

With the pistons removed, block halves split and connecting rods and crankshaft pulled out, all is revealed.
The thing I was most pleased about was the piston crowns. No signs of detonation at all. A testament to my mapper!

[Image: Picture051.jpg]

Shaun TDI
Junior Member
48
07-09-2018, 03:23 AM
#3
Unfortunately, when the crank went off to be measured, I was informed that the main journals had micro-fractures which ultimately meant that it was no good. :evil:
After lots of searching, I found a new nitrided crankshaft which will be more than capable of dealing with the power I'm hoping for.
As well as the newer stronger crank, I'm using H section forged steel connecting rods and Toda Racing pistons.

[Image: Picture052.jpg]

[Image: Picture054.jpg]

With the heads completely stripped, i decided that the appearance of them had to be worked on. Lets face it, if you'd spent 10 years living in an engine bay, you'd probably look like hell too...

[Image: Picture001.jpg]

[Image: Picture002.jpg]

With all of the grime, oil and oxidisation removed they look like brand new heads. It was at this point that decided to get involded in some porting and polished too. I didn't really want to get too involved and end up cutting loads of metal out so i decided on just removing the casting marks and removing the raised sections of the valve guides.

[Image: file.jpg]

[Image: file-1.jpg]

Its all starting to come together. I've managed to source 99% of the parts I'll need for the build and all I really needed was the time to do it.
With a few spare evenings, i began putting together the rotating assembly.

[Image: file-3.jpg]

[Image: file-2.jpg]

[Image: file-4.jpg]
Shaun TDI
07-09-2018, 03:23 AM #3

Unfortunately, when the crank went off to be measured, I was informed that the main journals had micro-fractures which ultimately meant that it was no good. :evil:
After lots of searching, I found a new nitrided crankshaft which will be more than capable of dealing with the power I'm hoping for.
As well as the newer stronger crank, I'm using H section forged steel connecting rods and Toda Racing pistons.

[Image: Picture052.jpg]

[Image: Picture054.jpg]

With the heads completely stripped, i decided that the appearance of them had to be worked on. Lets face it, if you'd spent 10 years living in an engine bay, you'd probably look like hell too...

[Image: Picture001.jpg]

[Image: Picture002.jpg]

With all of the grime, oil and oxidisation removed they look like brand new heads. It was at this point that decided to get involded in some porting and polished too. I didn't really want to get too involved and end up cutting loads of metal out so i decided on just removing the casting marks and removing the raised sections of the valve guides.

[Image: file.jpg]

[Image: file-1.jpg]

Its all starting to come together. I've managed to source 99% of the parts I'll need for the build and all I really needed was the time to do it.
With a few spare evenings, i began putting together the rotating assembly.

[Image: file-3.jpg]

[Image: file-2.jpg]

[Image: file-4.jpg]

Sparkystav
Administrator
14,683
07-09-2018, 03:40 AM
#4
Good build thread mate, i cant see the pics at work but the write up sounds good.

this all done out of hours at work? must be handy having the equipment to hand all the time lol

OutlawJapClub Admin Team
Sparkystav
07-09-2018, 03:40 AM #4

Good build thread mate, i cant see the pics at work but the write up sounds good.

this all done out of hours at work? must be handy having the equipment to hand all the time lol


OutlawJapClub Admin Team

Shaun TDI
Junior Member
48
07-09-2018, 03:42 AM
#5
The whole job was done out of hours. As much as I'd like to have done it all day...
Having all of the right facilities to hand was a huge benefit, not to mention all of the official tools and information.
Shaun TDI
07-09-2018, 03:42 AM #5

The whole job was done out of hours. As much as I'd like to have done it all day...
Having all of the right facilities to hand was a huge benefit, not to mention all of the official tools and information.

Stoney
Posting Freak
2,117
07-09-2018, 03:49 AM
#6
Looking good so far, though I have an idea you may not have finished yet!

[Image: tempsig2.jpg]
Confusedad: It was a tough call to make, but the Supercharged IS200 is being retired. Confusedad:
Stoney
07-09-2018, 03:49 AM #6

Looking good so far, though I have an idea you may not have finished yet!


[Image: tempsig2.jpg]
Confusedad: It was a tough call to make, but the Supercharged IS200 is being retired. Confusedad:

Shaun TDI
Junior Member
48
07-09-2018, 04:43 AM
#7
Unfortunately, I discovered that some of my case half bolts were no good so I had to source some more. The original bolts from Subaru main dealer were horrifically expensive, as were the ARP units. The most cost effective ones that i could find were made by Cosworth, but they still retailed at £321.50+ Vat, so not exactly cheap.

[Image: file-5.jpg]

Once the whole thing was assembled, it's time to make it all look pretty. I've decided on a black and silver colour theme so the first thing to do is paint the block halves.

[Image: file-8.jpg]

[Image: file-7.jpg]

Now it's time to start adding the ancillaries.
First up - Oil pump. This particular oil pump is a standard Subaru item which has been modified to give a higher static oil pressure.

[Image: file-6-1.jpg]

Second - Water pump. Again, just a standard Subaru water pump.

[Image: file-6.jpg]

Third - Sump ancilleries. For a long time i was debating whether or not to use the uprated Cosworth oil pan baffle which helps to reduce oil surge under high speed/high G cornering but my budget simply wont stretch that far right now.

[Image: file-9.jpg]

The oil filter/cooler was one of the few parts that didn't go off for plating. It's a shame really, as it stands out a bit.

[Image: file-10.jpg]

Most of the coolant hardpipes and breather lines have been rubbed back and given a coat of high-temp paint so that they look as good as new.

[Image: file-11.jpg]

[Image: file-12.jpg]
Shaun TDI
07-09-2018, 04:43 AM #7

Unfortunately, I discovered that some of my case half bolts were no good so I had to source some more. The original bolts from Subaru main dealer were horrifically expensive, as were the ARP units. The most cost effective ones that i could find were made by Cosworth, but they still retailed at £321.50+ Vat, so not exactly cheap.

[Image: file-5.jpg]

Once the whole thing was assembled, it's time to make it all look pretty. I've decided on a black and silver colour theme so the first thing to do is paint the block halves.

[Image: file-8.jpg]

[Image: file-7.jpg]

Now it's time to start adding the ancillaries.
First up - Oil pump. This particular oil pump is a standard Subaru item which has been modified to give a higher static oil pressure.

[Image: file-6-1.jpg]

Second - Water pump. Again, just a standard Subaru water pump.

[Image: file-6.jpg]

Third - Sump ancilleries. For a long time i was debating whether or not to use the uprated Cosworth oil pan baffle which helps to reduce oil surge under high speed/high G cornering but my budget simply wont stretch that far right now.

[Image: file-9.jpg]

The oil filter/cooler was one of the few parts that didn't go off for plating. It's a shame really, as it stands out a bit.

[Image: file-10.jpg]

Most of the coolant hardpipes and breather lines have been rubbed back and given a coat of high-temp paint so that they look as good as new.

[Image: file-11.jpg]

[Image: file-12.jpg]

Shaun TDI
Junior Member
48
07-09-2018, 04:44 AM
#8
For me, there'd be no point in doing it if it didn't look like it'd been done - :?
so far, I've had nothing but positive comments from people, including our very own engine builder who was impressed with my progress.

The next step was to dress and build up the intake manifold. I'd already got rid of the casting imperfections and opened the ports up to the gasket line but I didn't want to leave it looking standard. Masking it up was relatively simple...

[Image: file-13.jpg]

[Image: file-14.jpg]

With the metal fuel lines and the breather lines plated in the zinc pacifate, along with the relavent nuts and bolts, it all stands out really well against the black.

[Image: file-16.jpg]

[Image: file-17.jpg]

I dont normally like things polished, as they can be a pain in the **** to maintain but Dennis, one of our technicians, decided to kidnap my injector 'hats' and return them the following day fully polished.

[Image: file-18.jpg]

OK, so I spent some more time on it last night.
One of the parts that i found in the box was one that i'd already ordered a replacement for. Luckily, I can send it back so no harm done. This part hold the tensioner for the cambelt. With a quick treatment in the shotblast tank and then a paint up with new seals and 'viola'...

[Image: file-19.jpg]

[Image: file-21.jpg]

And with all of the idler pulleys and the tensioner...

[Image: file-20.jpg]

I also started preparing the main coolant pipework and then adding what i could at this stage.

[Image: file-22.jpg]

Once they were all on, i decided to fit the ARP headstuds, as i was supposed to be collecting the cylinder heads the following morning. Asides from putting the valves in, it should be a straight forward job.

[Image: file-23.jpg]

[Image: file-24.jpg]
Shaun TDI
07-09-2018, 04:44 AM #8

For me, there'd be no point in doing it if it didn't look like it'd been done - :?
so far, I've had nothing but positive comments from people, including our very own engine builder who was impressed with my progress.

The next step was to dress and build up the intake manifold. I'd already got rid of the casting imperfections and opened the ports up to the gasket line but I didn't want to leave it looking standard. Masking it up was relatively simple...

[Image: file-13.jpg]

[Image: file-14.jpg]

With the metal fuel lines and the breather lines plated in the zinc pacifate, along with the relavent nuts and bolts, it all stands out really well against the black.

[Image: file-16.jpg]

[Image: file-17.jpg]

I dont normally like things polished, as they can be a pain in the **** to maintain but Dennis, one of our technicians, decided to kidnap my injector 'hats' and return them the following day fully polished.

[Image: file-18.jpg]

OK, so I spent some more time on it last night.
One of the parts that i found in the box was one that i'd already ordered a replacement for. Luckily, I can send it back so no harm done. This part hold the tensioner for the cambelt. With a quick treatment in the shotblast tank and then a paint up with new seals and 'viola'...

[Image: file-19.jpg]

[Image: file-21.jpg]

And with all of the idler pulleys and the tensioner...

[Image: file-20.jpg]

I also started preparing the main coolant pipework and then adding what i could at this stage.

[Image: file-22.jpg]

Once they were all on, i decided to fit the ARP headstuds, as i was supposed to be collecting the cylinder heads the following morning. Asides from putting the valves in, it should be a straight forward job.

[Image: file-23.jpg]

[Image: file-24.jpg]

Shaun TDI
Junior Member
48
07-09-2018, 06:09 AM
#9
The plan was to have it ready to be put in by this weekend but i hit a problem last night with the valve clearances. For some reason, they've all changed on me, despite not changing a thing. If i get the chance, i'm going to look at it all again tonight.
Last night i did...

...another 2 brackets. These are the 2 that hold the PAS pump and the air-con pump.

[Image: file-25.jpg]

...the main toothed pulley for the crankshaft. This was horribly corroded so it also received the shot blasting treatment. There's no point in paint this as it'll never be seen again.

[Image: file-26.jpg]

I also finished the refurb on the coolant expansion tank, which i think now looks the bo****ks.

[Image: file-27.jpg]

I planned to stay late last night to finish building up the heads but it turns out that Subaru have sent me the correct thickness valve shims but the wrong diamater! GGRRRRR. After speaking with them early this morning, the correct ones can be obtained but they dont know how long they will be... This creates a fairly large problem - if they have to come Japan, then it's going to be several weeks before i get them and that seriously compromises the time table on finishing this project.

As you can see, these old shims are almost 2.0mm larger in diameter then the new ones.

[Image: IMG_0710.jpg]

[Image: IMG_0711.jpg]

OK, so since i couldn't proceed with the shim in the LH cylinder head, i decided to crack on with other bits. The shims can be done even with the heads on - it just means that i'll have to remove the camshafts to do it.

Bolting the heads on - relatively straight forward stuff... The luuuurvly Cosworth head gaskets. I'd calculated that these 1.1mm thick gaskets would be perfect in helping to retain the standard static compression ratio. Because the heads and block had been machined, the extra thickness in the gasket meant that everything was still the same distance apart. The last thing i wanted to do was lower the compression ratio, as the engine wasn't exactly 'spritely' in the first place and raising it would have simply lowered the ceiling of achievable safe boost levels.

[Image: file-28.jpg]

[Image: file-29.jpg]

The fully re-furbished cam covers in gloss black with all the fixings redone in the pacivate coating.

[Image: file-30.jpg]

Ialways think it's quite cool to see the fruits of your labour poking out. Nearly all aftermarket gaskets have some form of a tag - makes identifying quality componants on an engine a **** site easier...

[Image: file-32.jpg]

The new breather tops - if you remember, the old ones were cover in breaks. Didn't fancy re-using them much.

[Image: file-33.jpg]

The mighty HKS header. Luckily, this came with the car. Not only is this horrifically expensive (£698.50+) but i definitely wouldn't have had the room for this in the budget. True - I could have succumbed to a cheaper one like most of the absolute rubbish you tend to see floating around on eBay but i truly do believe that this is one of those rare items where 'you get what you pay for' rings very true.

[Image: file-34.jpg]
Shaun TDI
07-09-2018, 06:09 AM #9

The plan was to have it ready to be put in by this weekend but i hit a problem last night with the valve clearances. For some reason, they've all changed on me, despite not changing a thing. If i get the chance, i'm going to look at it all again tonight.
Last night i did...

...another 2 brackets. These are the 2 that hold the PAS pump and the air-con pump.

[Image: file-25.jpg]

...the main toothed pulley for the crankshaft. This was horribly corroded so it also received the shot blasting treatment. There's no point in paint this as it'll never be seen again.

[Image: file-26.jpg]

I also finished the refurb on the coolant expansion tank, which i think now looks the bo****ks.

[Image: file-27.jpg]

I planned to stay late last night to finish building up the heads but it turns out that Subaru have sent me the correct thickness valve shims but the wrong diamater! GGRRRRR. After speaking with them early this morning, the correct ones can be obtained but they dont know how long they will be... This creates a fairly large problem - if they have to come Japan, then it's going to be several weeks before i get them and that seriously compromises the time table on finishing this project.

As you can see, these old shims are almost 2.0mm larger in diameter then the new ones.

[Image: IMG_0710.jpg]

[Image: IMG_0711.jpg]

OK, so since i couldn't proceed with the shim in the LH cylinder head, i decided to crack on with other bits. The shims can be done even with the heads on - it just means that i'll have to remove the camshafts to do it.

Bolting the heads on - relatively straight forward stuff... The luuuurvly Cosworth head gaskets. I'd calculated that these 1.1mm thick gaskets would be perfect in helping to retain the standard static compression ratio. Because the heads and block had been machined, the extra thickness in the gasket meant that everything was still the same distance apart. The last thing i wanted to do was lower the compression ratio, as the engine wasn't exactly 'spritely' in the first place and raising it would have simply lowered the ceiling of achievable safe boost levels.

[Image: file-28.jpg]

[Image: file-29.jpg]

The fully re-furbished cam covers in gloss black with all the fixings redone in the pacivate coating.

[Image: file-30.jpg]

Ialways think it's quite cool to see the fruits of your labour poking out. Nearly all aftermarket gaskets have some form of a tag - makes identifying quality componants on an engine a **** site easier...

[Image: file-32.jpg]

The new breather tops - if you remember, the old ones were cover in breaks. Didn't fancy re-using them much.

[Image: file-33.jpg]

The mighty HKS header. Luckily, this came with the car. Not only is this horrifically expensive (£698.50+) but i definitely wouldn't have had the room for this in the budget. True - I could have succumbed to a cheaper one like most of the absolute rubbish you tend to see floating around on eBay but i truly do believe that this is one of those rare items where 'you get what you pay for' rings very true.

[Image: file-34.jpg]

Shaun TDI
Junior Member
48
07-09-2018, 06:10 AM
#10
OK - so where are we....
Over the last few days, things have come on in leaps and bounds. With the cylinder heads on, the exhaust header on and now the intake manifold fully assembled and installed, it actually starting to look like an engine again.
The camshaft pulleys are now on and so is the Cosworth timing belt.

[Image: file-35.jpg]

[Image: file-36.jpg]

With the covers on, its all hidden from sight...

[Image: file-37.jpg]

Next up - Turbo installation.
Although i didnt take any photo's, the intake on the turbo had some rather unusual casting marks, so i spent a few hours on Monday cutting them out and making good on it. I also spent a few hours cutting a few lumps and bumps out of the inside of the HKS exhaust manifold - these aren't defects with the manifold itself, but where the previous owner had an EGT probe welded in and then blanked off some time later, the weld stuck out quite a long way.

[Image: file-38.jpg]

[Image: file-39.jpg]

[Image: file-40.jpg]
Shaun TDI
07-09-2018, 06:10 AM #10

OK - so where are we....
Over the last few days, things have come on in leaps and bounds. With the cylinder heads on, the exhaust header on and now the intake manifold fully assembled and installed, it actually starting to look like an engine again.
The camshaft pulleys are now on and so is the Cosworth timing belt.

[Image: file-35.jpg]

[Image: file-36.jpg]

With the covers on, its all hidden from sight...

[Image: file-37.jpg]

Next up - Turbo installation.
Although i didnt take any photo's, the intake on the turbo had some rather unusual casting marks, so i spent a few hours on Monday cutting them out and making good on it. I also spent a few hours cutting a few lumps and bumps out of the inside of the HKS exhaust manifold - these aren't defects with the manifold itself, but where the previous owner had an EGT probe welded in and then blanked off some time later, the weld stuck out quite a long way.

[Image: file-38.jpg]

[Image: file-39.jpg]

[Image: file-40.jpg]

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