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Discussion Starter #1
Sorry if its a double post but is the na MKIII head the same as the turbo version? Talk about 1 hell of a brain fart. :dunno:
 

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desufnoC
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Yes, one cam is different, I think the intake. Oh, search next time, much covered topic. Otherwise identical.
 
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No they're not, the inlet tracts of the NA are shaped for a high speed flow while the Turbo's are shape for low speed & high volume.

I've just had £1600 of work done on my head, flowed, over size valve, etc.

I mistakenly had a NA on my Turbo & was disappointed when I only made 360bhp. Then I blew my HKS and decided to get the head worked on but it was damaged.
Sourced a second head but it was different, that's when the shop pointed out that the one I had one the car when it went was from a NA.

The NA is good for torque the Turbo for top end power. Hope that help.

I've got both heads in the garage I'll see if I can get some shots to show you.
 

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desufnoC
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wdragon said:
No they're not, the inlet tracts of the NA are shaped for a high speed flow while the Turbo's are shape for low speed & high volume.

I've just had £1600 of work done on my head, flowed, over size valve, etc.

I mistakenly had a NA on my Turbo & was disappointed when I only made 360bhp. Then I blew my HKS and decided to get the head worked on but it was damaged.
Sourced a second head but it was different, that's when the shop pointed out that the one I had one the car when it went was from a NA.

The NA is good for torque the Turbo for top end power. Hope that help.

I've got both heads in the garage I'll see if I can get some shots to show you.
Interesting, well, I've been wrong before, Thatll be cool to see.
 
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Discussion Starter #6
ma71supraturbo said:
There was a casting change mid 89, but as far as i know, no difference between NA and turbo
I don't know about that.

All I can say is that Len at the machine shop knows is stuff. He look at the marks on my old head and said my squish was all wrong & I wasn't getting the correct burn.
Then I told him it was a turbo every thing was fine. But the head has been designed with low down torque in mind.

Check his site out http://www.cylinderheadshop.co.uk/
 
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ma71supraturbo said:
There was a casting change mid 89, but as far as i know, no difference between NA and turbo
OK I stand corrected, but the question is why.

And why is it that in the toyota EPC the part number dosn't change between 8601-8808 & 8808-9305 but the casting does???????
 

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desufnoC
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wdragon said:
I don't know about that.

All I can say is that Len at the machine shop knows is stuff. He look at the marks on my old head and said my squish was all wrong & I wasn't getting the correct burn.
Then I told him it was a turbo every thing was fine. But the head has been designed with low down torque in mind.

Check his site out http://www.cylinderheadshop.co.uk/
From what I understand, this is because if the intake cam being different. The general consensus is the heads are the same. But your welcome to prove us wrong.
 

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Dr. Jeff Lange
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wdragon said:
OK I stand corrected, but the question is why.

And why is it that in the toyota EPC the part number dosn't change between 8601-8808 & 8808-9305 but the casting does???????
There were a LOT of casting changes to the 7M-GTE heads. At least 5-6 I believe, possibly even more.

The part number never changed, they were only minor design changes. Toyota does this semi-frequently, updates a part design, but leaves the part number the same. (Though, usually they will have the P/N superceed to another one).

Info on head casting changes:

http://www.mkiiitech.com/forums/viewtopic.php?t=167

Jeff Lange said:
There are 5 cam part numbers for the Supra, take from this message whatever you want, heh:

Intake:
13501-42020 - 86-87 N/A Intake Cam (38.36mm Lift (I think, I'm not 100% sure on that, can someone with an 87 TSRM check that for me?))
13501-42030 - 88-92 N/A Intake Cam (38.16mm Lift)
13501-42010 - Turbo Intake Cam (38.35mm Lift)

Exhaust:
13502-42020 - 86-87 N/A Exhaust Cam (38.36mm Lift)
13502-42010 - 88-92 N/A Exhaust Cam & Turbo Exhaust Cam (38.35mm Lift)

I have no duration information though.
 

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Dr. Jeff Lange
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Sorry Tony, you're wrong on the cranks. That number (13411) is the part name code for an engine crank, and is the same across almost all Toyotas, the last 5 digits of the P/N are important.

13411-42030 is the P/N for the 6M crank
13411-42040 is the P/N for the 7M crank

The cranks were more important to get the right one because of ECU differences based on redline change.
 
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Dr. Jeff Lange
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None of those numbers actually tell you the part number, you need to click on the number, then it will go to another page which lists all the part numbers for that part code.

It's much nicer using the actual Toyota EPC program than the website, but the website is pretty good. :)
 

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Dr. Jeff Lange
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I haven't used theirs, I have the EPC on my computer ;).

I have looked at theirs though, it's a lot newer than mine, and I'd like to have it, lol.
 
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