Top End Rebuild
#31
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I am returning with some updates.
All the engine parts are sitting in my basement [moved from trunk and garage]. I talked to Straitor, and he recommended using a grinding stone to port the heads.. so I picked up a few varieties of them at Sears. I will probably start the porting sometime this week. Is there anything I should be prepared for, or be caustious of?
I also talked to Straitor about decking the heads.. he said it wouldn't be possible, since there isn't a lot of clearance as-is. I just want a second opinion. I have zero clearance from the piston to the top of the block, and the heads don't have much more than 6mm from gasket mating surface, to the intake valve. I was thinking of decking the heads, to get a 9:1 compression ratio.
-justin
All the engine parts are sitting in my basement [moved from trunk and garage]. I talked to Straitor, and he recommended using a grinding stone to port the heads.. so I picked up a few varieties of them at Sears. I will probably start the porting sometime this week. Is there anything I should be prepared for, or be caustious of?
I also talked to Straitor about decking the heads.. he said it wouldn't be possible, since there isn't a lot of clearance as-is. I just want a second opinion. I have zero clearance from the piston to the top of the block, and the heads don't have much more than 6mm from gasket mating surface, to the intake valve. I was thinking of decking the heads, to get a 9:1 compression ratio.
-justin
#32
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Try not to port very far, don't get aggresive with it. If you hit a coolant channel you're hosed. Just go slow use light pressure and be cautious.
You're too tight to go too far, but definatly get them checked true.
You're too tight to go too far, but definatly get them checked true.
#33
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My coolant ports are nowhere near the intake ports. At least.. I don't think so. Wait.. the inlet for the coolant isn't near the inlet for the intake.. does that mean that the coolant ports run throughout the head.. and the intake ports may hit them? Ah ****, I never thought of that. How can I tell if I am getting close? I am only going to gasket match, which is 2-3mm of surface area. I was also thinking of cleaning up the exhaust ports.. since they have quite a bit of carbon build up. Should I just clean them up, or port them a little too? I don't think there is a whole lot of material I can take off of the header.. and I don't have any header gaskets, so I can't just gasket match. I'm thinking to just leave it alone, and just clean up the carbon.
-justin
-justin
#34
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Standard machining of the head will raise your compression by a quarter point, tops, apparently, but I dug up something from elsewhere that might bring a little insight:
... so doing the math, 0.2mm off in total bumped compression up from the stock 9.2:1 to 10.0:1, not sure if this 10.0 number is accurate at all, but it'* something to think about.
Originally Posted by ToyotaCressida.com Forums
If the machine shop requires a lot of milling, you might have to go with a metal gasket, simply to make up for the bigger gap between head & block. My 7M'* head was shaved 0.4mm and I ended up putting in a 1.4mm metal head gasket, this gave me a compression ratio of 10:1. Ideal hg thickness is about 1.2mm stock. so whatever gets removed should be made up for as long as you don't go past 1.0mm minimum thickness. On hot days I have to run 92 or 94 octane to prevent pinging.
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Head, Before
Head, After
They're hemi chambers, IIRC. This motor traces its lineage back to 1965, and even the original motor was the same way, albeit with a 2-valve head.
... It cost the guy (same guy who I quoted above) about $60 CDN to do this, and the job was rounded out with a metal head gasket and ARP bolts.
Might I add, he ported the head, as well.
His car (in Ottawa, Ontario) is holding up great, too. Advanced timing (these motors have distributors), 16" wheels, new paint (he did it himself, awesome job) everything. A prime example of a proper head job.
Head, After
They're hemi chambers, IIRC. This motor traces its lineage back to 1965, and even the original motor was the same way, albeit with a 2-valve head.
... It cost the guy (same guy who I quoted above) about $60 CDN to do this, and the job was rounded out with a metal head gasket and ARP bolts.
Might I add, he ported the head, as well.
Ok, here'* my ports..
A little minor cleanup, I don't expect to see much of any result, but it'* nice to know it'* clean and smooth in there. I used a metal grinding bit in a dremel with an extention.
I cleaned and polished all the valves yesterday. 24 valves takes a long friggin time!! now I'm going out to assemble. @$#% 24 valve retainers!!!
A little minor cleanup, I don't expect to see much of any result, but it'* nice to know it'* clean and smooth in there. I used a metal grinding bit in a dremel with an extention.
I cleaned and polished all the valves yesterday. 24 valves takes a long friggin time!! now I'm going out to assemble. @$#% 24 valve retainers!!!
His car (in Ottawa, Ontario) is holding up great, too. Advanced timing (these motors have distributors), 16" wheels, new paint (he did it himself, awesome job) everything. A prime example of a proper head job.
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It'* a 3.0L motor (190hp/185tq, iron block/aluminum head, Toyota'* 7M-GE, 7M-GTE if turbo), head-gaskets deluxe due to too low torque spec from the factory. A proper HG job (not necessarily metal gaskets) will ensure that the head gasket will never come a-knockin' for the life of the car It was around from '86.5 to 1992, so about the same era as the Vin C 3800.
Piston tops
You be the judge on these pistons, Jr... this pic is the same motor, different car.
Piston tops
You be the judge on these pistons, Jr... this pic is the same motor, different car.
#37
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I am thinking someone was hinting for some pics? Well, it'* your lucky day.
My rear Cylinder Head.. and some rockers
The bottom of my rear Cylinder Head --the head gasket came off very clean.. is that normal? I could just peel it off clean, right from the head.. but I am keeping it on, so I don't have to be so careful when laying it down, or whatever..
Another pic of the bottom of my rear Cylinder Head
A close up of the dome
An off center close up of the dome --notice how flat it is
A spot on my front Cylinder Head.. it seems to have black paint with some rust underneath.. anyone think I should sand down the rust, and repaint? It'* just surface rust.. but I am going to be painting so much stuff already.. it wouldn't hurt to mask off this thing and give it a shot of black.
My rusty Spark Plugs
A litte one for Straitor.. check your Yahoo offline IMs
It'* too damn cold for me to go out to the car.. it is supposed to warm up this week, so if it does, I will get some pics of some stuff in the car.
-justin
My rear Cylinder Head.. and some rockers
The bottom of my rear Cylinder Head --the head gasket came off very clean.. is that normal? I could just peel it off clean, right from the head.. but I am keeping it on, so I don't have to be so careful when laying it down, or whatever..
Another pic of the bottom of my rear Cylinder Head
A close up of the dome
An off center close up of the dome --notice how flat it is
A spot on my front Cylinder Head.. it seems to have black paint with some rust underneath.. anyone think I should sand down the rust, and repaint? It'* just surface rust.. but I am going to be painting so much stuff already.. it wouldn't hurt to mask off this thing and give it a shot of black.
My rusty Spark Plugs
A litte one for Straitor.. check your Yahoo offline IMs
It'* too damn cold for me to go out to the car.. it is supposed to warm up this week, so if it does, I will get some pics of some stuff in the car.
-justin
#38
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I went and grabbed my vin L head, they look exactly alike... Justin, did you have a bar under the rocker pedastals with the part # 24501397on it? I wonder if 93 rollers would fit on your 89 head.....
Pic #1, looks exactly the same, rockers are same but pedastal differs.
Pic #3, see those cast on numbers? Justin has 185, 14, 13... I have 136, 14, 8...
Justin , there'* numbers between the rockers, what are yours? I have M172 and 2138..
Pic #1, looks exactly the same, rockers are same but pedastal differs.
Pic #3, see those cast on numbers? Justin has 185, 14, 13... I have 136, 14, 8...
Justin , there'* numbers between the rockers, what are yours? I have M172 and 2138..
#39
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If the rear head were installed.. it would be on ther driver'* side. it has 3485. In the center, there is some sort of sun dial type thing.. and if it were installed, it would be pointing towards the firewall. Then on the passenger'* side I have something that looks like H033. The pics suck, and so do my lighting.. so it'* hard to tell.
-justin
-justin
#40
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*dances*
Straitor and I have come to the conclution.. that '93 rockers will fit on my heads. We have made a deal, and I bought some from him. I just couldn't wait to tell everyone . Also, after looking at my rockers for quite some time measuring, I noticed that my rockers were very worn where it rides on the spring. It'* too small to measure, but it'* almost worn flat [and the rocker isn't flat in that spot]. It seems a little much wear.. don't you think?
-justin
Straitor and I have come to the conclution.. that '93 rockers will fit on my heads. We have made a deal, and I bought some from him. I just couldn't wait to tell everyone . Also, after looking at my rockers for quite some time measuring, I noticed that my rockers were very worn where it rides on the spring. It'* too small to measure, but it'* almost worn flat [and the rocker isn't flat in that spot]. It seems a little much wear.. don't you think?
-justin