Building a 7ac

[B.Lane 88.]

I know that most of you guys are disinterested in this build because you have 16v and 20vs but I though I would post up for anyone wanting to build an interesting single cam set up. Ive been working on my 7ac for about a month now its nothing beastly but its a work in progress. I thouhght I would make a build thread for it as well as share all of the information Ive learned so far.

So the story begins with my AE86 I bought it about a year ago It was an automatic SR5 kouki coupe. I did the manual swap drove it for a few months and then my little 4ac dropped a valve . So thecar ended up sitting around untill I got some money to put her back together. Everyone and I do mean everyone told me to do a 4ag swap which cost to much, its fuel injected,making it harder to work on, and you have to buy a hard to find gts bell housing, plus I had just bought a new clutch flywheel and starter for my 4ac.I was talking to HVGuy who happend to have a 7afe and he was tellng me that he was thinking about building a 7ac it sounded like a good idea to me so I got 7a from him.

I took the 7a block to the shop and had it bored .50 over I had wanted to get forged pisotons for it but there were none what were affordable in the least bit so I had to go with cast. I thought about going with forged 4ag pistons or agze pistons but I did not want to complicate things futher. After boring it .50 over I had the shop blance the rods and put the rotating assembly together reseat the valves install double valve springs and I put my schnider racing cam in.
I put it all together I used a 4ac headgasket and a timing belt from an 85 doge colt cut the water outlet tube
because the 7a block is taller and put coolent hose over it I had to use the 7a lower timing belt sprocket set the timing marks and then put the 4ac one on I used the harmonic balancer from my 4ac because I wanted to run ac lol I also used an oil pump and belt tensoner from the 7a and I had to grind down the water pump to get the timing belt to clear. I put it in the car fired it up and everything ran pretty good.

Before I got it on the road the new thermostat failed to open so it overheated and blew the head gasket so I replaced it with the head gasket form the 7a which brought the compression up from 180 to 200. when I finally got to drive the car on the road its really good in first and second it still is far from a third gear motor which is what I wanted to see I have a really lowend cam in the car though it pulls like a single cam 240 in first and second but I plan on going turbo in the next few months im going to try and run 5-7 pounds of boost and see how it goes.
Here are some pics of the build I hope you guys enjoy it . If anyone is interested in doing this feel free to ask me questions about it

[DjSpecter]

OMFG!!!!!! YESSSSSSSS YESSSSSSSSS YESSSSSSSSSSSSSSSSSSSSSSSS!!!! YOU ARE AWESOME!!! I BEEN WAITING FOR SOMETHING LIKE THIS TO HAPPEN!! DUDE I WILL BE IN CONTACT WITH YOU ALOT NOW! LOL

[dr.occa]

don't be bashful with your build experiments and useful info bobby. good going with it. since you'll be turboing a carb'd setup, what carb do you plan to go with e.g. rebuilt factory or aftermarket? which rising rate fuel pressure regulator will you be using and are you going to go with a suck through non-intercooled or a blow through intercooled setup? looking forward to seeing the project unfold.

[B.Lane 88.]

don't be bashful with your build experiments and useful info bobby. good going with it. since you'll be turboing a carb'd setup, what carb do you plan to go with e.g. rebuilt factory or aftermarket? which rising rate fuel pressure regulator will you be using and are you going to go with a suck through non-intercooled or a blow through intercooled setup? looking forward to seeing the project unfold.

Thanks Jonas I will be posting more often now that im finally getting my car going. I would love to see some more people on the site I mean im on h240 but who really cares about a bunch of 240s and who really cares about club4ag Its cool that its an 86 site but its far from local.
As for the plans on going turbo for the carbureted system im going to use a carb hat on a weber 32/36 I installed a weber during the build. Im planning on doing a blow through intercooled system as for the fuel pressure regulator Im not sure which one I should pick from if you have any suggestions they will be greatly appreciated. Here is a link to the set up im planning on copying http://4ac-powered.forumotion.com/engin ... up-t29.htm" onclick="window.open(this.href);return false;
I was also wondering if you can use a water injection system on a carbed turbo system? I have seen pretty good results with them on fuel injected cars.

OMFG!!!!!! YESSSSSSSS YESSSSSSSSS YESSSSSSSSSSSSSSSSSSSSSSSS!!!! YOU ARE AWESOME!!! I BEEN WAITING FOR SOMETHING LIKE THIS TO HAPPEN!! DUDE I WILL BE IN CONTACT WITH YOU ALOT NOW! LOL

Thanks man yea pm me I'm be happy to talk about the set up anytime I'll also be at ggp tomorrow if your going you can check it out in person

[dr.occa]

...Im planning on doing a blow through intercooled system as for the fuel pressure regulator Im not sure which one I should pick from if you have any suggestions they will be greatly appreciated....

Mallory rising rate fuel pressure regulator.

[mooreofit]

nice build. if you wanted to squeeze a little more power during third retard the cam timing will move your power band up the rpm range.but you will not have this problem once boosted.

[Sam-Q]

I found on my 4ac that I gained power between 3000 and 4000 by advancing the cam gear 5 degrees

[B.Lane 88.]

I would degree the cam out but like mooreofit once I go turbo it shouldnt matter and hey if it does then ill work on it lol
but I took her to ggp last month and she did great in 3rd. I was really happy with the 7ac I cant link the whole track or anything but its
really fun lol

[mooreofit]

I found on my 4ac that I gained power between 3000 and 4000 by advancing the cam gear 5 degrees

good info.

on my 4afe i retarded the cams one tooth since no adjustible cam gears where available and it made a HUGE differance in the fe's ability to rev. before it sounded like it was going to grenade at 6500 rpms. now it will scream all the way to rev limeter no problem. i lost a little down low but as soon as it got all the timing in around 3000rpms it would really go for an fe motor

[DjSpecter]

UPDATE??

[B.Lane 88.]

UPDATE??

currently Im broke still trying to get my junk yard turbo system together but maybe by the end of next month ill have all the parts together

[DjSpecter]

If you need anything I have a good amount of 4ac junkstill left laying around. I would really liketo see this in person some time. What are the hp figures like or like a rough estimate?

[B.Lane 88.]

Ill let you know if I end up needing any more parts but I would love to bring out to a meet some time so you could check it out man. As for horse power I really dont know maybe 125 tops it has plenty of torque though. I'll get it dynoed after the turbo set up is done :].

[B.Lane 88.]

ok so its been awhile since Ive been on and I thought I would give you guys an update so far I have started building my turbo manifold and Im picking my fuel pump and fpr today so im going to try and finish all the fab work tomorrow take pics and give you guys a real up date and if everything goes ok Ill have the first turbo 7ac on the bored lol :]

[DjSpecter]

Dude you are pure motovation for me keeping the 4ac. Thanks and I will contact you shortly cause I just got a hold of a extra long block and would love to do the 7ac but non turbo lol.