absolutely wont work at all. 4A-C is 8Valves and GE 16valves.

 

I would have to change the pistons to get the correct notches for the valves ( right ) the bottom end is the same from what I understand .. 4a head to 4a bottom end

 

I wouldnt do it personally, yeah the head bolts on but the bottom end is build weaker that the 4A-GE is, the only thing that is the same is the bare block itself, all the internals are built to rev alot more than the 4A-C internals were ever designed to, plus it involves the same amount of work to do that as it would to do a 4A-GE swap to begin with, that would be the best bet for you.

 

It can be done, I have done it!

Although a G-head on a 4AC lower end is not the optimal setup, it will work just fine. The 4AC pistons are a lower compression piston, and you will notice a significant difference in power due to this compared to a 4AGE lower end, but they will not hit the valves in the G-head (unless you loose the timing belt at high rpms). The 4AC is not setup for an oil cooler which is OK if you don't plan to be drifting/running it at high rpms for extended periods. The oil pump timing cover is setup slightly different and will have to be cut up to fit correctly with a 4AGE cover and belt, as well as changing the timing gear on the crank. Besides that it is a direct bolt up. The performance of the lower compression pistons is a significant loss, and the motor sounds somewhat weaker than a complete 4AGE. You will also have to use the heavier 4AC flywheel due to the crank having 6 bolts and the 4AGE having 8 bolts, but the same clutch can be used.

If you have any questions feel free to contact me, i have spent much time wrenching on these things, and put together some bastardized combinations.

 

Although a G-head on a 4AC lower end is not the optimal setup, it will work just fine. The 4AC pistons are a lower compression piston, and you will notice a significant difference in power due to this compared to a 4AGE lower end, but they will not hit the valves in the G-head (unless you loose the timing belt at high rpms). The 4AC is not setup for an oil cooler which is OK if you don't plan to be drifting/running it at high rpms for extended periods. The oil pump timing cover is setup slightly different and will have to be cut up to fit correctly with a 4AGE cover and belt, as well as changing the timing gear on the crank. Besides that it is a direct bolt up. The performance of the lower compression pistons is a significant loss, and the motor sounds somewhat weaker than a complete 4AGE. You will also have to use the heavier 4AC flywheel due to the crank having 6 bolts and the 4AGE having 8 bolts, but the same clutch can be used.

If you have any questions feel free to contact me, i have spent much time wrenching on these things, and put together some bastardized combinations.

ok lets say i have a 4ac engine but i wanted to convert to a 4ag. woulndt 4ag internals (crank, conrods, pistons, crank end/main caps, crank/main bearings.) it should fit snug being basically the same block (right). what else would i need.

 

nice to hear from someone who knows what they are talking about . gives me hope that it will work .. I like my 89 celica with tvis so why not upgrade my sr5 for cheap.. thanks .:thumbup:

 

it would all fit in, but if I can ask? why do you want to do that?

 

cheap HP and fuel inject is better than the carb setup

 

it would be cheaper to just swap internals and the head wouldnt than to do a complete engine, tranny, and rear end swap (right)

 

I really dont see the point to do such. But the block is identicle between the 4AC and 4AGE the only forseeable reason to swap would be if your 4AC had a 7RIB block and your 4age was a 3rib...but even then the differences are only seen in a serious build where block strength is criticle.

Price wise, if you are going that far just get the complete 4AGE lower end. Then you wont have to deal with bearings (unless you plan to rebuild it) The reason i say this is every toyota bearing is fit per journal on the crank and block. Each block has a number stamped on each journal, as does the crank. Using these numbers you get a specific bearing size, which you bring to toyota which will give you bearings that have a near perfect fit. Unless you seriously know what you are doing inside of a motor, i reccomend using a complete lower end and not open the headache of cracking the lower end apart.

So in conclusion i would have to agree with 4agetercel's statement. "Unless you are getting it for free or damned near it, dont bother" The time that needs to be spent to do it correctly is great. And if its done wrong, well...you just lost a lower end.

 

not really, unless youre getting all the internals for free, or so damn cheap it might as well be free

 

yeah but nowadays you can find a whole 4age pretty damn cheap without having to do all this work swaping internals and all that shmeg, plus the 4ac doesnt have the oil cooler setup unless you swap that on too so you can rev it up all you want, like i said it really isnt worth the work unless your 4age's block has scored cylinder walls and you need a bare block to swap all the parts into, which in that case your internals are probubly damaged as well and need replacing

 

I wasnt going to swap the internals at all.( from what I understand now,is that a 4age head will fit on the 4ac short block with enough clearance for the 4 valve even though the 4ac is 2 valve , due to its lower compression .)

The reason I want to do this is that when I blow up the engine I will already have the correct wiring and such to put a complete 4ag in ..I would like to just have a good daily driver ( that has tvis and a better flow than a 2 valve ,not to mention the lower compression with the good atomization that the tvis provides will allow me to run a mid to low grade gas..)

 

why not just swap th whole 4age motor? if you want to keep your carb just get a side draft, better power and better sound. why complicate your self?

 

well yeah you wanted to go that route, JDG09 on the other hand wanted to swap in all the internals as well which was what my reply was concentrated to.

 

Best thing 4af carb 16v bottom,4age 16v oil pump,4af carb rods and pistons,if u have ABIT extra spring for 4afe pistons,7afe 0.6 mm head gasket ,20v head preferably silvertop cause the combustion chamber is smaller then black top , your compression nw is between 145 and 155 depending on your build ,standalone management rev limiter 7500 max ,trust me

 

Go to this link

http://www.club4ag.com/technical_main.htm

Im sure you'll find the answers you need

 

When I finally do attempt this swap I will be sure and document for all to see.

I have nothing to lose .
If the 16v 4ag head valves are going to hit the pistons I will save the 4ag head and put it on my 7afe and make me a 7age out of the 2.:thumbsup:

 

then youve gotta build the bottom end of the 7afe so it can rev higher, theres a sticky on here somewheres for the 7age, somewhere in the corolla forums

 

stock rods and crank are fine... been proven, just do a decent build and you should be ok.....

you don't want to use the stock 7a pistons, though

 

I'm sure they figured it out, this thread is from 17 years ago.