www.86garage.com

Im in the process of putting my hybrid together.

I pulled a 7a block from a 92 corolla. it had a spun rod bearing... and I think the rod is beyond the point of using, but since these rods are found few and far between, im going to assemble it the way it is now with new bearings.

It will have my old 4ac head with the new intake mani I made, along with a t3 flange header im in the process of building, but I cant finish it till its in the car and I can size everything up.


Im also about halfway done swapping the drive train from my corolla to my other car, and as I stated in a previous post, im trying to make an adapter plate for my 12a tranny. But most of my time lately is spent at work.

WHY THE 4AC HEAD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

nt66 wrote:WHY THE 4AC HEAD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

the head is where the 4AGE makes real power gains. maybe keeping remnants of the 4AC endears the coupe to hvguy more is my guess.

in spite of the fact that modification for modification, the 4AC will never out perform the 4AGE (which is essentially a base Cosworth engine) but as long as he's content with it, i think that's what matters in this situation.

it just the idea of the 7a is to put the 4ag head on it so it makes more power because the 4ag head flows better with a 4ac head it will be worse that stock but i guess its whatever floats your boat. After looking at that motor though I would STRONGLY recommend it at least get inspected by a machine shop I dont think that it will last 10 minuets with that rod in there

nt66 wrote:... After looking at that motor though I would STRONGLY recommend it at least get inspected by a machine shop I dont think that it will last 10 minuets with that rod in there

YIKES!

ive built a 7ac already lmk if u need any help. i had mine running for a year before it decided to have an arugment with the rod bearning and kick it out. its a fun engine and it even passes smog as well... real tourquey but it really felt like a truck engine. id reccomend getting 20valve st pistons for the higher compression as well as double race valve springs and a good cam. nothing crazy soming like what i used to have in my car which was a 232 dur @.50 before rockerarm ratio and .236 of lift before rocker arm ratio. a littte more lift would be better imo.

oh wait dead thread sorry

if the guy who started this thread pulled it from a 92 corolla than it is a 4afe. 7afe where implemented into the ae101's only as far as corollas are concurned. they where also fitted into celicas. but nice job on the 7ac !!!

raccoonracing wrote:ive built a 7ac already lmk if u need any help. i had mine running for a year before it decided to have an arugment with the rod bearning and kick it out. its a fun engine and it even passes smog as well... real tourquey but it really felt like a truck engine. id reccomend getting 20valve st pistons for the higher compression as well as double race valve springs and a good cam. nothing crazy soming like what i used to have in my car which was a 232 dur @.50 before rockerarm ratio and .236 of lift before rocker arm ratio. a littte more lift would be better imo.

Hey man I picked up the 7a from Hvguy and I plan on doing to the same thing with it. Currently I have had the crank machined and got new rod and main bearings I have 4ac head im going to have port and polished. I already have double valve springs and the biggest cam I could get from Schneider racing I just need one new rod a gasket kit and some money lol but I was wondering if I should the money boring it out or just hone the cylinder walls and what size 20v pistons will work do you have any suggestions?

B.Lane 88. wrote:Hey man I picked up the 7a from Hvguy and I plan on doing to the same thing with it. Currently I have had the crank machined and got new rod and main bearings I have 4ac head im going to have port and polished. I already have double valve springs and the biggest cam I could get from Schneider racing I just need one new rod a gasket kit and some money lol but I was wondering if I should the money boring it out or just hone the cylinder walls and what size 20v pistons will work do you have any suggestions?

the 4ac bore should be the same as all the other 4ag blocks (81mm). they're all 1.6 liters also.

might as well go .020" over since they are available over the counter that way as well...okay, except the 20v pistons but the 16v in standard and .020" over as well are readily had. check around and you'll come across wholesale deals on the 4ac low compression pistons.

dr.occa wrote:

B.Lane 88. wrote:Hey man I picked up the 7a from Hvguy and I plan on doing to the same thing with it. Currently I have had the crank machined and got new rod and main bearings I have 4ac head im going to have port and polished. I already have double valve springs and the biggest cam I could get from Schneider racing I just need one new rod a gasket kit and some money lol but I was wondering if I should the money boring it out or just hone the cylinder walls and what size 20v pistons will work do you have any suggestions?

the 4ac bore should be the same as all the other 4ag blocks (81mm). they're all 1.6 liters also.

might as well go .020" over since they are available over the counter that way as well...okay, except the 20v pistons but the 16v in standard and .020" over as well are readily had. check around and you'll come across wholesale deals on the 4ac low compression pistons.

Im using a 7a 1.8L block not the 4ac 1.6L block Im just going to use a 4ac head since I have one with a cam and double valve springs. I was planning on using the 1.6L head on the 1.8L block for high compression like the honda boys do. I have heard of people using 20v pistons in a 7a I just dont know what bore size I would need to do that.I was just wondering if I should just bore out the 7a .20 over for a small power increase or just hone the block and use 20v pistons

the 7a and 20v both have the same bore at 81mm.