Head Swap

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ColSwede
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My tercel:: 83 Tercel Wagon 4wd

Head Swap

Post by ColSwede » Tue Jun 11, 2019 6:31 pm

I've looked all over this site and don't see any info, and it might be a dumb question but for the sake of playing it safe... My 83 has the 3ac engine. My donor car has the 3a. Can I swap out the head, even Steven? Is there any differences at all? The engines look identical except mine doesn't have power steering or AC, and the donor car does... So the crank shaft pulley is different to accommodate the extras.

ColSwede
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My tercel:: 83 Tercel Wagon 4wd

Re: Head Swap

Post by ColSwede » Tue Jun 11, 2019 7:55 pm

Correction. I looked more closely and the valve covers do have some differences... I am wanting to pull the head from the donor car, get it rebuilt and then drop it on to my engine... At least, that's my hope.

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Petros
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Re: Head Swap

Post by Petros » Wed Jun 12, 2019 6:18 pm

mechanically and dimensionally they are identical. there may have been some minor changes on the accessory mount lugs, but nothing that will prevent you from using it.

while you are at it, replace the exhaust valves with new ones. they do not cost much, and they get heat fatigued and a pace can break off and damage your engine if you keep running the old exhaust valves. Intake valves can be resurfaced and used as long as wear is within spec.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

ColSwede
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My tercel:: 83 Tercel Wagon 4wd

Re: Head Swap

Post by ColSwede » Wed Jun 12, 2019 8:42 pm

Looks like Rock Auto has both. Is it hard to replace either ones?

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Petros
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Re: Head Swap

Post by Petros » Wed Jun 12, 2019 11:07 pm

the later 3a has what they call the "wavy" valve cover, the gasket line of the valve cover makes a few extra curves on the intake side (presumably to accommodate an anticipated fuel injection set up, but it was never imported). the valve cover takes a different gasket, but is other wise identical, both gaskets are available.

the heads, intake manifold, all other external accessories, etc. should swap over no problem.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

ColSwede
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Posts: 61
Joined: Tue Dec 25, 2018 9:11 pm
My tercel:: 83 Tercel Wagon 4wd

Re: Head Swap

Post by ColSwede » Thu Jun 13, 2019 5:07 am

So in theory, I can unbolt the 3a head and drop it right on to my 3ac engine? Just making sure I'm not missing anything.

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NWMO
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Re: Head Swap

Post by NWMO » Thu Jun 13, 2019 6:25 am

ColSwede,

Yes, you can swap without issue.

Chris
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ColSwede
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Posts: 61
Joined: Tue Dec 25, 2018 9:11 pm
My tercel:: 83 Tercel Wagon 4wd

Re: Head Swap

Post by ColSwede » Fri Jun 14, 2019 7:54 am

Awesome! Thank you all! Think I'll begin removing that 3A head, get new valves coming and see what I can do to get it all done up and ensure it is in great working order before sticking it onto my 3AC engine. Hoping it'll fix, or at least help, my oil burning issues.

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Petros
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Re: Head Swap

Post by Petros » Fri Jun 14, 2019 5:09 pm

the vale guides can wear as well, though usually they hold up well. if it has a lot of miles on it, and the oil was not always changed diligently, they will have wear. they too are inexpensive to buy, but the machine shop has to install them.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

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