hrm.... im not a mr2 specialist, but if your guna spend like 1200 on just fixing the motor, you might as well as go to a JDM engine shop, and just swap in the 4age Silver Top 20v motor, its a way better and stronger version of the 4age that you have, and it has 20v with individual throttle bodies, ive seen a complete motor, ecu, uncut harness and transmission for about $700 and you might be spending like another $200 on the harness to be modified for the mr2 and the transmission might cost you like another $200 or so for it to be modified for mid-rear setup from a front-front setup. but thats a option, or you can just rebuild the 4age motor, its still a nice high revving machine, but thats just my opinion if you were going to spent that kinda money on it, and you can still sell your messed up 4age engine for about $100 to people on the forums that cant afford expensive swaps, but just want to build a 4age for their non-4age car.

 

You can rebuild that motor for less than $800 guaranteed. I have rebuilt five 4AGE motors and they all cost between $500 and $800 to fully rebuilt (if you are going stock).

Just get a full rebuild kit, way cheaper. The kits cost $350-400 block and head machine work shouldnt be more then $200-350.

 

^ Thats the route I would go too. The easiest and most economical.

 

And even if you dont want to do a full rebuild (I recommend you do for longer engine life). As long as the journals weren't damaged, you could probably just have the crank machined and get just the bearings. A bearing set would cost about $50-75. Machine work $100. And it should literally take 3-8 hours of labor depending on how good the mechanic is.

 

Thank you for all your input. I'm thinking that, for now, i'll get it running as inexpensively as i can, and, if I love it as much as i think i will, i'll end up going with a 20v age or even a 3s engine later. Other than the living room, i don't have any space to rebuild it currently, or i'd be tempted to try to rebuild it myself. thanks guys, wish me luck

 

thats great news, the 4age in my book still one of the best motors i can think of. best of luck on the rebuild.

 

main bearings or rod bearings are shot?

not sure I've ever seen a 4age destroy it's mains.... even after rods have window'ed the block....

 

If you dont run the car with enough oil, or your oil pump goes...everything is fair game.

 

It's entirely possible that it's rod bearings, i talked with another mechanic who said its usually rods that go first, have to tear it apart to find out i guess. got some pricing going on with a couple mechanics to see what i'm actually gonna spend. I'd like to go full rebuild, anyone have any recommendations on performance cams? I wouldnt mind a bit of xtra HP.

 

you can also run into other problems like the crankshaft being scored beyond repair from the bearings being shot. So just something else to be aware of and account for.

 

I don't have a recommendation for Cams, but upgrading cams with higher lift/duration, requires upgrading of the valve train via stiffer springs and stronger retainers, at the least. You will also need adjustable cam gears to degree them .
You can't, or should I say shouldn't just throw cams in there. You risk valve float.

 

good to know, i figured i might need a new crank, but i'm hoping i don't. If i decide to go with a cam upgrade, i'll definitely follow your advice MR2Jedi. I really appreciate all the good advice I'll also try to get a pic or two posted of my mr2, in case anyone is interested.

 

If you end up needing parts for the car, we have a member here, mr2tim, who races 1st gens. He's got alot of spare parts that he wouldn't mind getting rid of.
You can always PM him and work out a deal. Tell him I sent you.

 

hks sells several sizes of cams.... a common size is 272's..... I think the stock computer will run it, but barely. Unlike honda's the 4age ecu's don't have much in the way of modifiability (there's a couple things you can do but finding those that know how and the specifics are far and few between).

if the motor is an 86 3 rib then you might want to reconsider finding a newer motor to work with to begin with. the 3 ribs aren't all that bad.... in fact I tend to prefer them for n/a purposes.... but finding pistons (other than stock) can be difficult as they use a different wrist pin than the later versions.

if you decide to go this route you might want to look into a last 16V version... the smallport. It was found here in the US in 90/91 corolla gts and geo prizm gsi. They make a bit more power and aren't all that difficult to find.

 

alternator

i watched an episode of wheeler dealers and they bought a first gen mr2 to restore and sell . the one they bought had a noise coming from the bottom end that sounded like the bearings and it ended up being the alternator. something about water pooling up and dripping on the alternator making the bearings rust out and make a grumbling noise. the alternator is on the bottom so it makes people think its coming from the bearings. id try replacing the alternator first. you may save yoursellf a lot of time and money that way.

 

that show is full of crap.

although many complain of alternator failures.... of the 11 aw11's I've had.... not a single one has had an alt fail on me (starters, yes). The only toyota I've had with a failed alternator is my ae92.... which has the alternator in the same location and water does NOT get to it.

 

thank you for the info about mr2tim, the cams, and all the advice, it's definitely helping me. I'm still in research phase, but you guys have all given me plenty to research
As far as the alternator goes, i originally thought the noise was the alternator, so went ahead and bought the car. then when the mechanic said bearings, i didnt even check the alt for myself. whether it's common or not, i should probably at least make sure about it before i do anything else, so thanks for that also.

 

p.s. do i have to upgrade membership to put the cool sig where i list all my cars and stuff like that?................. ok, i dont really have any other cool cars, but i have a 2003 dodge quadcab, 89 chevy king cab long bed, and a bitchin lil 96 saturn SL2 that goes at least 132 mph by accident. hehe

 

ok, i checked the alternator......... when the accelerator is let off and the noise starts the alternator pulley and belt start shaking violently. woo hooo ! ! I went and ordered an alternator at the local parts store for $100. I'm gonna have to slap myself for not double checking the mechanic if that takes care of all the noise. I know it's at least part of it.

Thanks for that post, made me get off my butt and check it out personally.

 

alternator wasn't all of the problem, but it wasnt in good shape either, on to researching motors LOL