Head's done - milled .010 off for a bit of power. (1 Viewer)

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Josh83 said:
When I spoke with Robbie about head milling and gas octane, he indicated that .010-.015 off the head should not require anything more than regular gas.

Perhaps, but lots of folks have posted about hearing pinging while running regular gas.
 
I think that "lots of folks" are running around with some pretty fouled plugs/valves/pistons/injectors. People use crap gas to a surprising degree, and if you bought one used and haven't started a regular cylinder environment cleaning regimen such as Techron, etc then you should if you're getting pinging. Of course a timing check wouldn't be a bad idea, either. My bro in law's 293,000 mile 93 doesn't ping, nor does my 4 degree advanced 93, nor my 97. Icleaned it with techron upon buying it, and when the head came off I was pleasantly surprised there was relatively little carbon in there. I think a couple more Techrons would have done it completely, though the machine shop made it spotless today - heh.

DougM
 
IdahoDoug said:
I think that "lots of folks" are running around with some pretty fouled plugs/valves/pistons/injectors. People use crap gas to a surprising degree, and if you bought one used and haven't started a regular cylinder environment cleaning regimen such as Techron, etc then you should if you're getting pinging. Of course a timing check wouldn't be a bad idea, either. My bro in law's 293,000 mile 93 doesn't ping, nor does my 4 degree advanced 93, nor my 97. Icleaned it with techron upon buying it, and when the head came off I was pleasantly surprised there was relatively little carbon in there. I think a couple more Techrons would have done it completely, though the machine shop made it spotless today - heh.

DougM

which of the Techron was this?
 
It's the Techron Concentrate, not the everyday stuff. Same bottle, but more juice
 
Doug,
You gunna take the lower intake runner off and clean it?

Great PM while it available to be done.

Great work!!
 
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Doug, Did you give any consideration to any porting of the head?
 
Leaving the intake manifold in the engine bay is a good trick to deal with the wiring. Another idea is to cut out some of the manifold so that it is free of the wiring:

https://forum.ih8mud.com/showthread.php?t=22415

I fortunately haven't had a chance to examine my manifold close up--does cutting this section out seem like it would work without leading to leaks?

Mike
 
Doug,

Stick an arrow in that picture where the PHH is located if visible.

Thanks.
 
Alia,

I'm not that high tech, but you can see it as it's the snazzy blue silicone hose. Look at the rear most cylinder, and then to the right about two inches you'll see a flash of blue. That's it. It's disconected and pushed an inch back from the block.

I did not consider any porting or polishing. Sometimes, as you clearly saw here with the first shop, you can have someone do work like that and end up with problems. Someone like Robbie I'd trust in a heartbeat because he's got the right ethic, AND he knows the head well. But someone hunting around the head with a grinder for better airflow might cause problems down the road. I'm looking for durability and sometimes taking material out of an alloy head like that moves away from durability.

Mike, I remember that thread. I think that will work fine as well. Just that doing it my way keeps everything stock while avoiding dealing with the engine bay wiring harness. I don't know what the long term ramifications are, but it's worth noting that Toyota puts a massive steel strut on the intake manifold to help it handle stress. Taking that connecting web out of the intake manifold may allow it to vibrate, shake, etc. Dunno.

DougM
 
alia176 said:
Stick an arrow in that picture where the PHH is located if visible.

See the wire bundle going down, next to the second intake opening from the firewall?

Measure pretty much straight down about a foot and that is the PHH.

It's definitely not visible from above with the manifold in place.

John Davies
 
Well, I've driven it 150 miles now and the engine is notably stronger. Honestly, it's hard to say whether that's due to the valve job or the added compression, but the engine feels eager to pull with just the slightest throttle. I floored it today and was also pleased to feel the difference at the 1-2 shift where it clicked off the shift and continued pulling almost uninterrupted. Before, the thrust definitely dropped off but now the shift is more of a nonevent in terms of thrust.

At idle in Park, the engine also revs instantly and drops instantly - far better throttle response vs the normal 1FZs kinda lazy off idle response. Yesterday while idling it to flush I revved it frequently while pulling on the throttle body cable and I've never noticed how much it rocks the engine and body. The engine note seems more snarly, too.

Still has a slight miss at idle every once in a while which every 80 I've driven does. Almost like a cylinder drops out once every 10 seconds or so with no pattern. Interesting that a complete throttle body cleaning, new plugs, a sterile cylinder head, a valve job, timing check, and fresh head gasket had no effect. Must be fuel related - injectors or at idle the software has it super thready to minimize fuel use.

Anyhow, I'd highly recommend this minor mod (mill .010) to anyone pulling their head.

DougM
 
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good for you, but let's see the drag race results, eh! :)
 
That's coming. In fact, my bro in law may be interested in driving one while he's visiting so we'll have a pair of trained track guys. Spy vs Spy.....

DougM
 
Come on Doug...... race results?
 
Hmm, I wonder how the milling would affect a supercharged version. Anyone??
Cheers,
Sean
 
Sean,

More compression, more powahhhh!

The roads have been snowy for a week now, so not exactly race conditions. Supposed to continue with light snow till midweek. Hoping for a matchup before we leave for Christmas.

DougM
 

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