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Discussion Starter · #1 ·
Last year I almost picked up a 1990 90q20v but financial issues kept that from happening right away. Low and behold, it sold to another person who just recently put it back up for sale so within the next 2 weeks it SHOULD be in my garage and I can get started working on it.

Obviously I am looking to go the ghetto 20vt route, my neighbor (Kuma) has an MC2 block from his Autotragic 200 that he parted last year and has pretty much offered it up to me sans pistons/rods for nearly free. I have read through PKW and death4kq's threads and havent dug up the info I am looking for to be honest.

The crank journals for the con-rods. What are the size differences between 10v-20v? I know the 10v's had smaller journals but were all 20v journals the same? I was thinking something along the lines of this >>>

MC2 block, 7a Crank, AAN Pistons/Rods, and possibly stock 3b engine management if I can have it for the cheap, if not then I will end up going full standalone with VEMS (most likely will go the VEMS route anyways but just giving myself options). So what I am asking is are the AAN rod journals the same as the 7A journals?

Now I know that putting a 7a head on an MC2 results in very low compression as well as very little clearance between the valves and pistons (which is why PKW machined in reliefs into his pistons) BUT If the combination I listed would work, does anyone have a clue what the clearance would look like between pistons and valves?

This is all in the planning stage still, as I am going to wait to tear into the engine until after Vagabahn in Dallas this year (Nov timeframe) so this will be a winter project but I want to start getting all the info and parts that I will need so I can have it done and running between Feb-Apr next year. I am not shooting for 500whp just a good scootin car putting down maybe 300whp (Turbo will most likely be a holset hx35 or similar).
 

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Discussion Starter · #2 ·
To clarify, this is me assuming that the MC engines and AAN share the same size bore. I may be wrong though so please someone correct me.
 

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SapperMike said:
MC2 block, 7a Crank, AAN Pistons/Rods, and possibly stock 3b engine management if I can have it for the cheap, if not then I will end up going full standalone with VEMS (most likely will go the VEMS route anyways but just giving myself options). So what I am asking is are the AAN rod journals the same as the 7A journals?

Now I know that putting a 7a head on an MC2 results in very low compression as well as very little clearance between the valves and pistons (which is why PKW machined in reliefs into his pistons) BUT If the combination I listed would work, does anyone have a clue what the clearance would look like between pistons and valves?

300whp (Turbo will most likely be a holset hx35 or similar).
that combo should work well and will not require extra valve clearance because the aan pistons are already designed to clear the valves in a 20v head. i suggest an hY35 for the hp level.
hth
 

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Discussion Starter · #4 ·
Those were my thoughts as well. So essentially it would be a 2.2l I5 turbo with a 7A head and oil-fed turbo :) I guess ill hit up that guy on audifans this weekend about those aan rods/pistons.

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Discussion Starter · #5 ·
Now I also assume that I would need to figure out provisions for accessories or are the 20v/10v similar? I am only planning on running an alternator, ac system is already shot on the 90q and for PS I am looking into the electric pump like Javad did in his 80q.

Also, I also assume I would use a 3B/7A TB kit along with an AAN headgasket? Just bouncing ideas here.
 

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everything from my 7a bolted up to my mc2 block. ps pump probably depends on what intake you go with but of course the electric one works with all.
 

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Discussion Starter · #7 ·
So the only issue I should run into is getting a proper length belt to run only the alternator.

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Discussion Starter · #8 ·
So if anyone else wants to chime in how does this idea sound,

Rebuild with the used aan pistons and rods I picked up from Ben Howell and tune, once I get the tune done where I want it bump up to aftermarket rods like scat from 034 or dmforged from iroz and simultaneously have the pistons coated?

I think it would be a good route to go incase I screw up the tune and bend a rod or melt a piston, as well as I know the stock rods and pistons can handle the power I am shooting for but want to give myself room to grow in the future. I definitely dont plan on bigggg power anytime soon but I know I will get the itch eventually and want to be prepared when it comes so I can just turn up the wick and not worry about breaking anything.

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