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The mkiv Supra Owners Club

SRD to the rescue...!


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OMG, even the cams aren't reusable, am I right by thinking that if the cams are damaged, it means there is no more parts ok in an engine... ??

 

Do you know now from where was the low oil pressure ? The bad clutch adjustment doesn't explain this, this was an other problem I think.

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There was some scoring on the cam journals originally, presumably from the previous oil issues, but now I have seen the photos it looks like the engine has been run on sand, not oil! The cam journals don't see that much loading, but the scoring will lead to more oil bypass, and lower pressure for a given flow rate. I am thinking there is something contaminating the oil system, and my immediate suspect would be the cam covers. There's definitely been some abrasive material in the oil, the thing's ground itself to destruction. What's the inside of the oil pump like? If you change the head I'd be in no rush to find a VVTi one, the gains are not significant and cam choice limited.

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There was some scoring on the cam journals originally, presumably from the previous oil issues, but now I have seen the photos it looks like the engine has been run on sand, not oil! The cam journals don't see that much loading, but the scoring will lead to more oil bypass, and lower pressure for a given flow rate. I am thinking there is something contaminating the oil system, and my immediate suspect would be the cam covers. There's definitely been some abrasive material in the oil, the thing's ground itself to destruction. What's the inside of the oil pump like? If you change the head I'd be in no rush to find a VVTi one, the gains are not significant and cam choice limited.

 

Can the surfaces not be smoothed out again? And the cylinders bored out to fit larger Pistons?

 

I only ask as I'm not an engine builder and am really curious and surely that would be better than a whole new engine? Especially if that's going to be built too?

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The block could take another bore, there's a further oversize piston commonly available. But the damage around the thrust faces of the main cap and block region that hold the thrust washers would be the deciding factor. Can't tell from photos, they would need measuring and checking for flatness. I don't think Toyota list oversized thrust washers but i may be wrong. let me look....

 

No, only standard thickness.

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The block could take another bore, there's a further oversize piston commonly available. But the damage around the thrust faces of the main cap and block region that hold the thrust washers would be the deciding factor. Can't tell from photos, they would need measuring and checking for flatness. I don't think Toyota list oversized thrust washers but i may be wrong. let me look....

 

No, only standard thickness.

 

Chris you mention about the polished cam covers but you fitted the covers yourself did you not check; how don't you know for sure?

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I didn't take the rivetted in baffles out, no. I just washed them out in the Grease |Eater. I am only guessing at a possible source of contamination. I have no idea if they were bead blasted, soda blasted, walnut shell blasted, not blasted, or how they were processed and polished, just speculation and my trying to help. You have the build photos, the engine was hot tanked, then bare head and block had the oilways steamed and rifle brushed out. Then steamed again and hot air dried. I presumed the covers were OK internally, having come off a running engine, that's really the polishers job. But it certainly looks like something gritty has been through the lubrication system from the photos. That "glue" is the smear of Loctite sealant on the front cam caps, to stop the head / cap joint leaking externally, as someone has already pointed out. I may have a good crank coming in.

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You can get a full Aristo VVTI Engine with auxiliaries for 1699$+shipping... Comes out at 2000-2300$ depending on company that sells the Engine. If you add tax etc it will work out at 2000-2300€ and you'd have a fully working engine and car that will hold 700bhp. IMHO that would be the cheapest option for now. After the car is running you could still upgrade the new engine if you want to.

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You can get a full Aristo VVTI Engine with auxiliaries for 1699$+shipping... Comes out at 2000-2300$ depending on company that sells the Engine. If you add tax etc it will work out at 2000-2300€ and you'd have a fully working engine and car that will hold 700bhp. IMHO that would be the cheapest option for now. After the car is running you could still upgrade the new engine if you want to.

 

The aristo engine has the sump in a different location!

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