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Discussion Starter #1
I've been doing a lot of reading regarding A-series hybrids, both 7A and 9A. I saw someone post something about the weight of a 2ZZ crank on the 9A Information post and decided to research his claim of a weight loss. Pretty sure it was bogus ( http://www.mr2oc.com/showpost.php?p=4357741&postcount=97 ) but I wanted to know.

I was not able to find the weight of a 7AFE crank, if someone knows or can add to the discussion that would be great. I have seen weights for 4AGE cranks range from 26 lbs for small journal to 28.5 lbs for 20V cranks. Taking the information from the MWR website, a stock 2ZZ crank should weigh around 27 lbs. You can also purchase a balanced and knife edged crank from them for $675 (used crank) or $950 (new crank) that weighs "less than 25 lbs". Not a bad thing to be able to purchase off the shelf parts for this conversion.

On that note, one "issue" with using a 7AFE crank was the lack of choices for off the shelf 6 bolt lightweight flywheels and uprated clutches. There are many choices for the 2ZZ, though I haven't seen any information regarding the use of a 2ZZ flywheel with a c-series transmission for an A-series block.

To clarify, this would be:

7A-FE block
2ZZ Crank (85mm stroke compared to 7A-FE 85.5mm)
7A-FE rods
4A-GE pistons

I was also looking at improving the rod/stroke ratio using 2ZZ rods.

137.9 mm = 2zz rod
132.5 mm = 7afe rod

4AGE piston height = 30mm

Is my math wrong that you would need a piston to have an approx height of 27mm on a 206mm 7A block? That is probably a tall order for a piston to retain reliability.

I am just putting my mind on to paper. Feel free to discuss!
 

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Discussion Starter #2
I found an error in the 9A information page. It says that the 1ZZ, 2ZZ and 7AFE rods all have the same big end size. Not the case.

7A-FE Big end = 51mm
1ZZ and 2ZZ = 48mm

There might be a solution to this: Mazda BP rods happen to be 48mm big end, 20mm pin end, and 133mm center to center (7AFE is 132.5mm). Both ends of the rod will need to be narrowed down to the 2ZZ spec of .780" from .860", and I am no machinist but I would think if they were planed and then re-balanced everything would be a-okay. This also opens you up to a whole slew of choices for rods (Carrillo A-Beam, H-Beam, Pauter X-Beam, Eagle H-Beam).

So, do-over:

7A-FE Block
2ZZ Crank
Mazda BP Rods
4A-GE Pistons
 

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How much displacement are you looking for? I thought 9a conversions were for more displacement. Now I believe the 1zz has a longer stroke than the 2zz. I believe when they designed the 2zz, they went with a shorter stroke than the 1zz, but with a bigger bore. I have heard of people using 1zz cranks in 2zz blocks to pick up some cubes.
 

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Discussion Starter #4
I am only trying to brainstorm some different ways to go about a 7AGE.

I believe you are correct on the 1ZZ crank for 2ZZ strokers and its use in the mythical 9A builds, but I am not looking for that. The 9A thread in the stickies did lead me to this thought though (regarding the use of a 2ZZ crank for reduction of rotating weight, and in the process gaining more options for flywheels).
 

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Have you seen the post for the 9A crank that is now available?

I'm all about throwing out ideas for the sake of bashing out theories just as mathematical exercises as long as that's all this is. There are such easier and cheaper routes to get to a goal than trying to frankenstein the above setup together.
 

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Then why do you bring it up? I swear this forum is all talk and bogus theory sometimes... Maybe it's cause we're all too broke to do anything about it :thumbdown

Manon Racing Products in New Zealand is releasing a 7A/9A stroker kit to achieve 1900cc of displacement. The kit will include pistons, rods, billet crank (8-bolt utilizing OEM 4AGE journal sizes), bearings and wrist pins. The rod:stroke ratio will be somewhere between 1.5:1 and 1.55:1. They are working with U.S. manufacturers, not cheap Chinese junk. It will cost $3,500NZD ($2,906USD) plus shipping. You can choose between I-beam and H-beam rods, and compression ratios of either 11.0:1/13.4:1 or 8.7:1 for turbo applications, either 16v of 20v.

I highly doubt it's worth it to muck about with a ZZ crank and rods and several pages of internet theories trying to get it to work as well as this kit will. I too pored over those 9AG threads trying to find examples of successful builds, and was only able to find two people claiming to have achieved a running 1.9-2.0L A-series. There was very little documentation, and the owners were nowhere to be found. Lots of questionable machine work was involved, too. I don't think it's worth it unless you're chasing some seriously wild horsepower numbers, but nonetheless very cool that it's available:

http://www.mrpltd.co.nz/product/290/7a-stroker-kit-deposit.html
 

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Discussion Starter #8 (Edited)
Turbowned said:
Then why do you bring it up? I swear this forum is all talk and bogus theory sometimes... Maybe it's cause we're all too broke to do anything about it :thumbdown
The title of this thread is "Brainstorming: 7A-GE with 2ZZ crank". I've said "I don't want to build a 9A" more times than I thought I'd have to in a thread about a different way to look at building a 7A-GE. The only time I've even brought up the 9A was to say that I saw some information in the 9A thread. Don't know how make that any clearer.

Turbowned said:
Manon Racing Products in New Zealand is releasing a 7A/9A stroker kit...
I'm sure this kit is nice if something beyond a 7A-GE is your goal. The part that would bother me about this is the piston. They are claiming 6% longer rod than a 7A (132.5 + 6% = 141mm) with a 90mm stroke. A 7A-FE block has a deck height of 206mm, so with some quick math, that would make a near 20mm compression height piston. This would likely have the piston pin behind the oil control ring. That is not exactly desirable for a street engine or longevity.

I guess my title wasn't to the point enough and the information I posted lead people to think I was trying to discuss something TOTALLY different.

What I am trying to discuss on this forum for "engine swaps and related discussion" is a different way to build a 7A-GE that MIGHT improve some elements e.g. the use of a lighter, accessible crank that has been proven to 700 HP, better flywheel/clutch availability and better rod selection.
 

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Marine Crankshaft......... up to 91.5mm stroke :thumbup

Marine Crankshaft makes quite a few Toyota "A" cranks. I'm sure a 91+mm stroke "A" crank isn't cheap, but to have a 1.9 liter(1932cc to be precise) "A" engine while keeping the bore @ 82mm (more stable bores)



this one isn't that large ;)

everything else you get made to order(fit)
 

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Discussion Starter #10
OST - Keeping with a 85mm stroke to build a 7A-GE motor, would you think it worthwhile to use a lighter 2ZZ crank over a 7A-FE crank? I believe I remember reading on one of your builds that you chose to use a early 4A-GE crank with 40mm journals because of its weight.

Unless all of the information about using a ZZ crank in a 7A block is incorrect, it seems that it would only require a bit of machining to clearance the crank to the block on the mains. Then for the rods the use of Mazda BP rods with narrowed ends. This would still allow you to use any stock 4A-GE piston.

I know this is all a lot of untested theory, but if a 7A-GE is a desirable engine with some quirks, why not look into ways to give it an upgrade without a custom crank, rods and pistons?
 

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the 1zz is 91.5mm stroke. Probably not a coincidence. If the 1zz and 2zz cranks can be swapped around in the 2zz, and the 2zz and 7afe can be swapped around in the 7afe block, then it is likely the 1zz could go into the 7afe. FWIW the 1zz crank spins 8.5 - 9k in some 2zz stroker builds.

As to the flywheel situation - the 4ag flywheel will not go on a 2zz crank. I tried to do this a few weeks ago with a fidanza flywheel and my 2zz. The concentric part that sticks out of the crank is bigger on the 2zz than the 4ag.
http://www.youtube.com/jdchmiel in my youtube channel I have a few videos details the flywheel / pressure plate / clutch disc differences. You can use the disc and pressure plate from either motor. I have the red clutchnet 4ag plate on my stock 2zz flywheel. I think the bolt circle is a bit bigger on the 1zz/2zz than the 4ag as well, but having a wide range of non-custom choices makes it not an issue at all, it just makes it simpler to use the 1zz / 2zz flywheel instead of having crank machined for 4ag flywheel to fit.

So I like your solution -
2zz crank ( -.5mm stroke)
BP rods ( +.5mm length)
7a block ( pistons sit .5mm below deck in stock 7afe)
4ag pistons ( pistons are flush with deck in stock 4ag)
Should end up working out quite nicely.
Personally, I would try to get the 1zz crank working, but the rod piston combo is still a big question mark. So that leas me to a question - how / where are you finding out info on mazda rods / compression height on 4ag pistons etc...?
 

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Discussion Starter #12
Jared said:
the 1zz is 91.5mm stroke. Probably not a coincidence. If the 1zz and 2zz cranks can be swapped around in the 2zz, and the 2zz and 7afe can be swapped around in the 7afe block, then it is likely the 1zz could go into the 7afe. FWIW the 1zz crank spins 8.5 - 9k in some 2zz stroker builds.
My logic was similar. I was investigating a 7A-GE build, and knew from previous research that a 1ZZ crank would swap into a 2ZZ. After finding some information on 7A-FE and 1ZZ crank swapping in a 7A-FE block, I decided to look into the possibility of using the 2ZZ crank in a 7A-FE block.

Jared said:
As to the flywheel situation - the 4ag flywheel will not go on a 2zz crank. I tried to do this a few weeks ago with a fidanza flywheel and my 2zz. The concentric part that sticks out of the crank is bigger on the 2zz than the 4ag.
http://www.youtube.com/jdchmiel in my youtube channel I have a few videos details the flywheel / pressure plate / clutch disc differences. You can use the disc and pressure plate from either motor. I have the red clutchnet 4ag plate on my stock 2zz flywheel. I think the bolt circle is a bit bigger on the 1zz/2zz than the 4ag as well, but having a wide range of non-custom choices makes it not an issue at all, it just makes it simpler to use the 1zz / 2zz flywheel instead of having crank machined for 4ag flywheel to fit.
I think that using a 2ZZ flywheel and clutch is the solution. The only thing I do not know is the engagement of the starter on a 2ZZ flywheel with an A-series bellhousing.

Jared said:
So I like your solution -
2zz crank ( -.5mm stroke)
BP rods ( +.5mm length)
7a block ( pistons sit .5mm below deck in stock 7afe)
4ag pistons ( pistons are flush with deck in stock 4ag)
Should end up working out quite nicely.
That's my thinking! The math adds up and I think the benefits of the crank shaft and it's strength, the Mazda BP rod and 2ZZ flywheel options vs. 7A-FE options would make it worthwhile to spend a couple hundred dollars on machine work to get there.

Numbers:
7A deck = 206mm
7A-FE crank = 85.5mm stroke
2ZZ-GE crank = 85mm stroke
7A-FE rods = 132.5mm length
Mazda BP rods = 132.84mm length
4A-GE 16v pistons = 30mm compression height (I believe some 20V pistons are 30.5mm tall)

Jared said:
Personally, I would try to get the 1zz crank working, but the rod piston combo is still a big question mark.
I too like the idea of a 2.0L 4A-GE, but the deck height of the 7A-FE is a limiting factor. A 133mm rod and 85mm stroke gets you 1.565:1 ratio (a stock 4A-GE is about 1.58:1), versus something like a 1.42:1 with a 1ZZ crank and 4A pistons. The shortest pistons I think could be made (and reliably used), 27-28mm pistons should allow use of the same rods but still give you a sub 1.5:1 rod/stroke ratio.

Jared said:
So that leas me to a question - how / where are you finding out info on mazda rods / compression height on 4ag pistons etc...?
Most of the information Im getting is either from 7A/9A information threads here, the Crower Import connecting rod master catalog, Wiseco master catalogs or through internet searching. Im taking my own findings with a grain of salt until I can fund a build, though.
 

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flipflop said:
I think that using a 2ZZ flywheel and clutch is the solution. The only thing I do not know is the engagement of the starter on a 2ZZ flywheel with an A-series bellhousing.
I'm pretty sure most Toyotas use the same ring gear, but here's a pic of the 2zzge flywheel and then one from a corolla all-trac, which is the same as a 4agze flywheel but with 6 holes.





106 teeth on both. I got those pics from standardflywheels.com BTW.
 

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Last discussion I read on the subject I heard a couple people say something like .015 in below the deck. .5 mm come out to .019 so it seems pretty close.
I think when people say it's level that's an eyeballing kind of thing and it actually sits just below the deck.
 

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okay, B18 pistons + rods gets 45mm crank side, 30mm compression height, 21mm pin,
137mm rod. 4ag crank is 42mm. Is there such thing as bearings that are 3mm oversize?
 

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its easier to have a set of custom rods made and use the 7afe crankshaft

The 2zzge crankshaft does fit BUT needs material removal in the center to fit the main journals
I cant remember the numbers but its been years


overall the 2zzge it is a better made crankshaft and requires machining to fit in the 7afe block
BUT the rod journals are different you will need custom rods made or find something that will fit the height of the piston you use
you can bore the block to raise cc by 1mm or 1.5mm 2 is very close and is only suggested for all motor due to thickness left between the cylinder walls but again you have to dig for a set of pistons I used a set of honda aftermarket used CP pistons

Its a pricey swap but doable alot of people stopped because it was too much of find this, find that, machine this
is it worth the extra cc?? if your willing to spend the extra money
9AGE is old stuff now you can buy cranks made to fit with off the shelf parts that are alot better designed
Honestly to avoid headache frustration its easier to buy a premade set or just get a hold of 1zz and 2zz parts and dive headfirst in
I loved all motor but now im a sucker for high compression turbo engines
 
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