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manual head on auto bottom end

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ESXTEZZ
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manual head on auto bottom end

Postby ESXTEZZ » Mon Nov 19, 2012 12:52 pm

Does anyone know if you can use the manual head with the auto bottom end and pistons, are the cut outs in the auto pistons deep enough for the manual valves and cams.
I'm thinking of sticking a spare manual head onto the auto engine that I'm currently running in my car, I want to see what difference the bigger valves and Maury cams make to power with the supercharger at its current boost level.

xeraptor
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Re: manual head on auto bottom end

Postby xeraptor » Mon Nov 19, 2012 5:15 pm

I've read couple of ppl saying they did it with no bottom end modifications on russian altezza forum.
It would be interesting to know the difference in power under boost.
I want to try to put MT cams in AT head myself.

ESXTEZZ
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Re: manual head on auto bottom end

Postby ESXTEZZ » Mon Nov 19, 2012 6:51 pm

The advantages of the manual head over the auto head that ive found are:
cams have more lift, intake valves are titanium, intake valves are 3mm larger, exhaust valves are 1.5mm larger.
The manual intake manifold has 10mm longer intake runners than the auto, which should give beter low down torque.

assassin10000
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Re: manual head on auto bottom end

Postby assassin10000 » Thu Jan 03, 2013 6:01 am

ESXTEZZ wrote:The advantages of the manual head over the auto head that ive found are:
cams have more lift, intake valves are titanium, intake valves are 3mm larger, exhaust valves are 1.5mm larger.
The manual intake manifold has 10mm longer intake runners than the auto, which should give beter low down torque.


Checked toyodiy.com. Looks like piston part #'s are the same for both auto & manual. The cylinder heads appear to be different part #'s. I wonder if they skimmed the manual heads for higher compression?

Andrew

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Re: manual head on auto bottom end

Postby Celica RA45 » Thu Jan 03, 2013 11:05 am

auto is 11to 1 .manual block 11.5to 1 valves are 34,5mm auto 35mm manual
exhaust are the same 29.5 mm
manual has more comp and lighter valves for the extra 10 hp cams are the same

HKS200
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Re: manual head on auto bottom end

Postby HKS200 » Thu Jan 10, 2013 4:41 am

to achieve the same compression ratio as a manual motor all you need to do is get a 0.5mm thinner head gasket. every 0.5mm thinner = 0.4 comp more and vice versa. I've got a manual box behind a auto motor, auto motor are said to make torque much earlier than manual motors.

ESXTEZZ
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Re: manual head on auto bottom end

Postby ESXTEZZ » Thu Jan 10, 2013 5:41 pm

So are the Manual and Auto bottom end identical then ???? ive only stripped a manual never an auto

rautho
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Re: manual head on auto bottom end

Postby rautho » Wed Aug 20, 2014 7:28 pm

As i have NOT found a definitive answer on any of the forums i have searched on, let me post my findings on: manual head on auto bottom end & head swap Altezza questions.

A week ago our RS200Z automatic timingbelt broke, and bent all the exhaust valves and two intakes. Being an automatic the head was equipped with steel valves and thus bent when contacting the pistons...Thankfully we were just at lazy cruise at 60km/hr showing about 1300rpm engine speed. Pistons and head suffered absolutely no damage. Now mind you, even though Altezza"s are plentiful here, parts are not And especially for the 3SGE BEAMS.The local stealership is no help at all as they are anti-rhd(that's another story). We did manage a gasket or two based on part numbers we got, but that was it. So I had to call on the local RHD and Altezza community for help.
Now mind you, i had no previous experience with these cars whatsoever let alone the engine.
But as i have stated before i have scoured all accessible forums and this thread provided me with the definitive push to go ahead and do what was left to me as the only short term solution: fit a manual head in place of the automatic one.

As finding new or even used valves provided to next to impossible, this used engine from a manual car kept popping up in my inbox.
So I decided to take the plunge, and decided to go for it. But there is always a catch, isn't there? The head was still on the block with cams on etc. So i would have to disassemble to find out if it was usable as the owner couldn't tell me what happened to the engine....At least i could wrench to my hearts content...
Well, turns out the head was in PERFECT condition. Plus the seller let me have the cams and gears too...at a price that was like,"i love you , man" :D
He got free labor on various parts he could now resell separately.

Well, the assembly went without a hitch...and oh...another answer i couldn't find to this question: Can you re-use the stock metal head gasket? YES, you can. Provided you re-coat it properly(my case i used copper spray by Permatex) DISCLAIMER: this method was used on a head-gasket that was not blown/ overheated. Head and block mating surfaces must be CLEAN before installing the gasket. Your results may vary depending on a variety of factors concerning your particular case. I had to because no new gaskets were readily available.
Oh, yes...VERY IMPORTANT: USE THE MANUAL FOR DIS-AND RE ASSEMBLY.

Very pleased that it fired up right away after priming the engine(which was a ecu reset right away :P ) and settled in a nice smooth idle..
I did a 60km shakedown run in varied terrain at low throttle openings to let the vvti do it's thing.(you know..waiting to hear that: ratatatat clang-clang..boom! noise :lol: ) Well, she ran beautifully, and even felt raring to go, but too soon to say for sure..Dyno session maybe?

So yes folks you can swap heads. the manual benefits: larger Titanium valves, upgraded springs and buckets. Would not be able to tell if compression is raised because of the head/ headgasket. Better revability? still to be seen.... As for the cams: some say the manual carries hotter cams than the manual....no verdict there on my part. But if they are, so far they are nice at low revs. Higher up in the rev range? We will have to see...If not: who cares? My girlfriend does not care about high revs like i do :lol: :lol:

please feel free to ask any questions on anything I may not have laid out on my 2nd longggggg arse post. Hope it was a good read...

PS: bottom ends ARE identical...

Cheers!


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