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OST-056: Nasty.....
Posted: Wed May 01, 2019 9:56 am
by oldeskewltoy
Another first gen 4AG head, this one is a bit Nasty....
Btw, here is a photo showing the difference between a 1st gen TVIS head, and a 2nd gen TVIS head. A first gen is what came on the AE86, the 2nd gen is later
So, getting back to OST-056, the head is stripped, cleaned(?), and pressure checked. Once back, I deburr the casting
more to come......
Re: OST-056: Nasty.....
Posted: Wed May 01, 2019 4:35 pm
by Sprite
Thanks, Nice to see the comparison, looking forward to seeing the build.
Re: OST-056: Nasty.....
Posted: Wed May 01, 2019 5:50 pm
by Rogue-AE95
oldeskewltoy wrote:Btw, here is a photo showing the difference between a 1st gen TVIS head, and a 2nd gen TVIS head. A first gen is what came on the AE86, the 2nd gen is later
I have to wonder if Toyota had the MR / FWD mounting in mind when they (or Yamaha) designed the 4A-GE. I have one each of the big port heads and noticed this difference.
Re: OST-056: Nasty.....
Posted: Mon May 06, 2019 10:05 am
by oldeskewltoy
Rogue-AE95 wrote:oldeskewltoy wrote:Btw, here is a photo showing the difference between a 1st gen TVIS head, and a 2nd gen TVIS head. A first gen is what came on the AE86, the 2nd gen is later
I have to wonder if Toyota had the MR / FWD mounting in mind when they (or Yamaha) designed the 4A-GE. I have one each of the big port heads and noticed this difference.
I've yet to see a Toyota application that uses that mount...........
Work on the head proceeds.....
"Building" the intake side - blending the seat, bowl, and port
also working the exhaust side
more to come......
Re: OST-056: Nasty.....
Posted: Mon May 06, 2019 5:25 pm
by Rogue-AE95
oldeskewltoy wrote:I've yet to see a Toyota application that uses that mount...........
There's a small bracket that bolts to that part of the head. At least for the AE92 GTS. There's a hole in the top timing belt cover for it to stick out of. Then there's a plate which mounts from that bracket to the top of the alternator bracket. I have a pic somewhere of the pieces, I'll have to post it. There may be more to it but I forget. I pulled everything from a junkyard AE92 GTS.
Edit: here's a pic. The bracket is on the far right. I think the middle plate/bracket also bolts to the engine mount. There's 2 holes at that end, one of which bolts to the small bracket situated between the cam gears.
Re: OST-056: Nasty.....
Posted: Tue May 07, 2019 12:22 pm
by oldeskewltoy
Rogue-AE95 wrote:oldeskewltoy wrote:I've yet to see a Toyota application that uses that mount...........
There's a hole in the top timing belt cover for it to stick out of.
Can you show me this /\ timing cover... all I've ever seen is the typical fwd cover \/...
Re: OST-056: Nasty.....
Posted: Wed May 08, 2019 6:27 pm
by Rogue-AE95
I'm sorry I derailed the topic with this, but I guess we all learn something new every day. And I always love to see your work!
OK, here are some better pics. I had pulled all of the timing covers for my (someday, someday, someday) engine build, along with that small "cam bracket."
^ Bracket looks smooth in parts because I've been taking off the casting lines & imperfections, so that I can get it powder coated along with other parts.
Re: OST-056: Nasty.....
Posted: Wed May 08, 2019 6:59 pm
by oldeskewltoy
new to me.....
Re: OST-056: Nasty.....
Posted: Fri May 10, 2019 12:03 pm
by oldeskewltoy
After learning about the timing cover from Rogue-AE95....
good lesson(for everyone)... even if you think you know it all....... you don'tNow, back to OST-056....
oldeskewltoy wrote:
A facebook "viewer" asked if my work fits the stock gasket... I assured him it does......
Further progress... 3 down... 1 to go
more to come.......
Re: OST-056: Nasty.....
Posted: Thu May 16, 2019 3:13 pm
by oldeskewltoy
back from the machine shop wearing a new 3 angle, and back cut intake valves....
next, checking chamber volumes...
So if I want chambers down to 36cc, how much should I have machined from the head???
more to come....
Re: OST-056: Nasty.....
Posted: Fri May 17, 2019 8:54 am
by oldeskewltoy
from another forum wrote:It's very late so my math might be off but I think about 1.5 thou (inches) sounds wrong but that's all I can come up with right now. I'm rusty with my numbers and a bit tipsy.
well, about .008" is about 1cc(+ or -), so @ .6cc over, that would be about .005"
and that's how much I had it machined.....
more to come....
Re: OST-056: Nasty.....
Posted: Mon May 20, 2019 12:03 pm
by oldeskewltoy
The head is now ready for re-assembly....