WRX STI Scoobyclinic build report (Project Dotty)

[Jay762]

Overview

 

This report details the results of a build completed by Scoobyclinic. It illustrates that a combination of parts, which on correct assembly could result in an engine capable of a solid 440bhp but fail completely within a very short space of time (approx 6200 miles) due to a number of reasons - Head studs incorrectly fitted, head bolts not torqued down, machined faces scored, liners proud of block, poor honing and piston to cylinder gap intolerance

 

History

Built by ScoobyClinic for Mikee Singh

Sold by M Singh to James Bastable

Sold by J Bastable to Paul @ Midwest Performance

Bought from Midwest Performance by me

 

 

Advert from the Midwest site

http://midwestperformance.co.uk/product/2008-subaru-wrx-sti-505-bhp-scooby-clinic-racing-spec/

 

2008 WRX STI,Massive Scooby Clinic Racing Spec, 5000 miles since forged engine rebuild, , 480 bhp and 500 ft lb pump fuel v power, 505 bhp & 525 ft lb on 20% meth, Mapped by Mark and pat at Subaru Specialists Scooby Clinic, , Syvecs S6 GP ECU with syvecs expander, , Toucan touch screen display, , 6 switchable maps, , Launch control, , Anti lag, , Engine:, SMG linered ej257 block, Built by mark Wilson at clinic, JDM Hatch Spec C Dual AVCS Heads, FIC 1100cc injectors, Spark plugs ngk 7, Mahle Forged pistons, Manley rods, ARP Studs, Cosworth Gasket, Twinscroll sump, New Billet SC46 (high flow turbine)…… The car was built by scooby clinic for one of there in house racing drivers as his daily car

 

 

Kev @ Scoobyclinic has confirmed the spec as described in the advert and that the build was completed by Mark – quoted as being a “£12k build” by email. The engine numbers could not be confirmed as it was an internal project and that data is not retained by SC

The parts listed have been confirmed on strip down which identifies the engine to be the original build unit:

ARP Studs

Mahle pistons

Manley Rods

Linered EJ 257 block

          Spec C heads

 

 

Mileage on car when collected                         Circa 38000 (Online MOT history confirms this to be valid)

 

Mileage when rebuild was completed                Circa 32900

Current mileage                                                       39064

 

Approximate mileage completed by myself                1000

Approximate mileage completed since rebuild            6160

 

 

 

Both J Bastable and Midwest Performance have stated no engine work or parts were replaced on the motor by them.

 

The Report

 

Leaking crank seal

 

All cam pulley bolts were very loose except n/s exhaust pulley.

• It is suspected that was tightened up properly making the timing belt slip on that pulley hence the rest being dangerously loose, they would have continued to gradually loosen until falling out completely

All clearances on timing guides were incorrect, these are fitted to ensure the timing belt does not jump teeth.

• How these were fitted it’s not possible they could do their job correctly.

 

Damage from a tool under one of the cam seals.

• It looks like the seal may have been hammered too far in then a screwdriver used to pull it out damaging the head

 

A single bearing timing belt small guide idler bearing fitted

• The 2.5l STI has a dual bearing type as standard due to the heat and load that can be generated in the bearing race

 

 

The oil pump had inadequate sealant.

• Whilst it was not leaking at the point of engine failure it had the potential to fail in the near future

 

 

This oil pump is a Cosworth modified Subaru 10mm oil pump & this engine is dual AVCS so should be fitted with a 12mm oil pump as standard. (OEM Part number: 15010-AA310)

• As it is an aftermarket oil pump with a smaller diameter but with the potential to generate increased pressure it is contentious as to the oil supply requirements, pressure vs flow rate capability. For a dual AVCS 2.5l unit there is a high probability this would be insufficient

The specific mounting bolts which require three bond sealant on assembly had none applied resulting in eventual oil leakage  

Head studs fitted incorrectly.

• This potentially caused / contributed to the failure of the cylinder head gaskets.

The head gaskets have definitely failed in several places.

• It cannot be ascertained 100% if there was the reuse of old head gaskets in this build.
• The damage on the gaskets could be attributed to either vibration caused by the head studs being incorrectly fitted - not being torqued as required or that old head gaskets have been used resulting in cylinder head gasket failure.
• Given the relatively low mileage since the rebuild (circa 6164 miles) and the damage to the gaskets themselves this would indicate the reuse of old gaskets.

 

On removal of head studs from the block, grit was present in the threads.

• This means the head studs will not have been torqued down correctly

 

The face of the head shows scoring.

• This will have been incurred either on assembly with the face being moved on a rough surface or during the machining process - blunt tool or material being picked up from the sleeve and dragged across the surface

 

The sleeve itself is prominent above the deck not machined flush.

 

 

There are signs of the engine burning excessive oil, evident by the burnt oil on the crown of all pistons

 

 

The pistons have picked up in their bores.

• This could be down to incorrect piston / wall clearances or a poor quality build - not completing pre installation tolerance measurements.

 

The bores have been honed incorrectly (too shallow an angle on the hone)

• This has contributed to oil usage due to oil bypassing the rings.

 

 

[Siluro]

Well that is a damning report. Ouch, reusing the head gaskets. Thanks for posting.

[savage bulldogs]

Gutted for you jay , I dare say you were sold the car with the understanding it had a strong built engine. 

I've only built 5 or so boxer lumps but those machine faces , honing angles and sleeve fitments are shocking.  With only 6k on the engine (if it was built right first time) it should only just be run in ,not needing a rebuild 🤔

With the same parts list in the block ,I find it difficult to believe that it's been replaced ,especially as the block has sleeves (badly) fitted with probably a cheap diy "ball hone" at the wrong angle 🙁

Looks like they threw a few high spec parts in a block just to keep their driver happy and didn't do a clean high £12k spec build after all 🙁

Have you sent s.c a copy of the teardown report and if so have they replied yet ?

[Siluro]

I think SC will know about it by now anyway. And yes gutted for you but I assumed you knew what you were getting into. As I said I am glad this was posted. I have heard so many stories like this who can you trust. People on hear think nothing of saying if you want your 2.5 to be reliable just build the motor. Well easier said than done judging by this report unless you are capable of doing it yourself.

How can they sleep at night, where is people's pride in their work. Based on this they obviously do not give a stuff and just want to take your money.

[Jay762]

Just for info - I did promise to share the result with SC and have done so by email

[savage bulldogs]

Tbh I didn't think you'd have shared the findings on here before showing them , just wondered what they had to say about this apparently thrown together "built" engine .

I understand if it was built in house for a employee, that you might use what's to hand but most of the faults are from bad engine machine and build practices. Not from re used measured ,checked and cleaned second hand parts .

I also understand that if you work on a lot of cars that the law of averages will mean you'd have a chance of having more unhappy customers (ratio) .

As performance cars get pushed and parts can fail but imo the workmanship/labour should always be on point in any service/ business. 

Best of luck with it, Jay .

[Siluro]

6 minutes ago, savage bulldogs said:

Tbh I didn't think you'd have shared the findings on here before showing them , just wondered what they had to say about this apparently thrown together "built" engine .

I understand if it was built in house for a employee, that you might use what's to hand but most of the faults are from bad engine machine and build practices. Not from re used measured ,checked and cleaned second hand parts .

I also understand that if you work on a lot of cars that the law of averages will mean you'd have a chance of having more unhappy customers (ratio) .

As performance cars get pushed and parts can fail but imo the workmanship/labour should always be on point in any service/ business. 

Best of luck with it, Jay .

You seem to be giving them some wriggle room. There is no excuse and I would be interested in what they have to say about it.

[savage bulldogs]

No bud not at all , it was sold as a car with a £12k  built engine . I was just pointing out that even if it was built for a employee ,you'd expect at least a minimum level of skill to be used by tuning company engine builders .

I'm a self employed plasterer that apparently builds to a better standard on the wifes kitchen table 🤐 .

Will be interesting to see what they have to say about it, though .

 

[Siluro]

50 minutes ago, savage bulldogs said:

No bud not at all , it was sold as a car with a £12k  built engine . I was just pointing out that even if it was built for a employee ,you'd expect at least a minimum level of skill to be used by tuning company engine builders .

I'm a self employed plasterer that apparently builds to a better standard on the wifes kitchen table 🤐 .

Will be interesting to see what they have to say about it, though .

 

Ahh ok my bad. 

Looks like I could do better on the kitchen floor and I have never done work on a car to that degree (head gasket is as far as that goes). I have to do most of my car work in the public road outside my terrace house, which is mainly basic maintenance (touch wood so far). I need to move and get a garage as over the years I have learnt to not trust anyone with my car including so called dealerships. I can be a parts replacer that is easy, proper basic diagnosis is woefully lacking judging by the threads you see on the forums and my experience with local garages. You cannot trust anyone to do a decent job anymore. You can have all the certificates and qualifications you want, means jack if you have no pride in your work.

[Jay762]

1 hour ago, savage bulldogs said:

Tbh I didn't think you'd have shared the findings on here before showing them , just wondered what they had to say about this apparently thrown together "built" engine .

Best of luck with it, Jay .

I had, response received stated that any liability / issue is between myself and the dealer I purchased the motor off  

[Tidgy]

Shall see what develops with this, cos im sure thats not the state it left clinic in as i know where, how and who builds ever engine that comes out of clinic and i don't believe he would even entertain considering that, let alone actualy do it.

 

For comparison, some pics of my engine mid build on this thread with surface faces visible, every engine they build is done in the same way, same machine shop does the block prep work.

 

[Siluro]

Any more development on this or have you bitten the bullet and are going to just sort it yourself? Shame really as it looks a lovely car. Whoever is responsible should be named and shamed.

[Jay762]

I have received no additional response form Scooby Clinic. They have already formal stated any liability is between myself and the dealer so I know it will definitely be down to me to address.

I had spoken to the dealer before xmas and shared my expectations of him in this instance which would be cost of labour for the rebuild and cost of a new set of Cosworth or equivalent capable head gaskets - This I thought was fair.

I will be getting a quote for the rebuild labour sent so I can have that discussion with him outside of the rest of the build communications. 

[savage bulldogs]

Gutted the original builders seem to have washed their hands of any liability,  hopefully the garage you bought it off will help with the cost . After all you only did just under 1k miles before you noticed it was fubared .

Best of luck ,bud