View Full Version : Problem with rebuilt motor from AEBS

11-04-2004, 06:27 PM
I just had my Motor rebuilt by AEBS and i have been having nothing but issues this is what the motor has done to it

Sleeved block
90 mm ross pistons
tomei rods
Tomei 260 cams
Stock intake manifold and no port work
i have 555cc injectors with a Power Fc and z32
It has burned oil sense day one AEBS tells me this is from running lean tell me what u guys think the motor only has 1200 miles on it


11-04-2004, 07:38 PM
Did they get new seals for the valves? No valve guide and valve seat work? Do they give u the clearances between the engine parts? Maybe they made things on hte loose side and u need thicker oil. I know forged pistons expand more, do u drive it when the engine is cold?

11-04-2004, 08:29 PM
I had new valve stem seals and new bronze valve guides put in the head..........we disassembled the head today and found no problem with the head.They said to use 10w 30 motor oil not anything thicker than that.they set the bearings up to .0018 clearance.the piston clearance is .005.......they said that the scaring on the piston and sleeves where from running lean.They said i should run a 13.5 A/F at idle and 11.5 A/F when i see zero vaccum and under wide open i should have the A/F at about 10.5.........They also said that the S14 intake manifold has a issue of leaning out cylinder 4...........now how true this is i dont know.I always thought to make good power the proper A/f sure be arouond 11.5 and the highest 12.0 under full boost

11-05-2004, 12:02 AM
from the pix, it LOOKS like the rings were not clocked correctly or it was dirty/dry on engine start up. I don't think a lean condition would cause this AT ALL, especially if you weren't beating on it. What turbo are you running? Are you SURE the seals are good and the oil return is not inhibited in anyway? Did you run synthetic on start up or dino? Lastly, try a thicker oil, after break in I wholely recommend 15w50 Mobil 1 synthetic, 20w50 during break in. I dont have a whole lot of faith in that company based on a friend's problems with his block that he recieved from them, and it was only sleeved, the tolerances were WAY off. He can chime in if he wants to. They don't seem to know as much as they should know, considering how vaunted their name is in the import racing world.

11-05-2004, 12:09 AM
Off topic but how much was teh sleeving?

11-05-2004, 07:46 AM
The rings were clocked properly.............and we checked the bore and it was fine and we checked the piston clearance and it was ok .........They sad the piston swoll past the piston clearance and the skirt rubbed the cylinder walls.Also iam running the Tomei Arms B8446 and it is not leaking any oil

To have the blocked sleeved and oring they charge 1300 plus shipping

11-05-2004, 09:02 AM

Another victim of those guys over there...I'm sorry to see you had problems like this.

How about a 4 month wait to get a block sleeved...only to get it back with the bores 1mm off center!!

What i would do if i were you is try to get the specs on what tolerances they built the motor to. those a$$holes tried to tell me i needed to run 0.007" of piston to wall clearance. I called my piston manufacturer and they laughed at such a bogus claim. Excessive piston-wall clearnce casues excessive piston slap and wobbling in the bores. thsi results in rounded off rings and poor cylinder sealing. They obviously have no clue what they are doing out there and have NO quality control. I know a certian somone...who may choose to chime in...that had their sleeves drop on one of his motors.

It looks like piston-wall clearance was wrong from the get go. did the motor have alot of piston slap? the pistons are only showing wear perpindicular to the wrist pin. this could have been a case where the piston was rocking in the bore excessively and thus scored up the walls.

How hard have you driven this motor? How well is it tuned? usually the first thing you need to do with a built motor is get it on a wideband and ensure that everything is righ with the AFR's. running the motor under load without enough fuel can casue the pistons to overexpand...but you have to have it loaded up for thsi to happen. it's not goign to happen under low load conditions.

drop me an e-mail and i'll share some more info with you.

-edit...just read your your other post:

0.005 is a stupid amount of piston-wall clearance. you shouldnt ened mroe than 0.0035 for a street motor seeing 500 whp or less.

AFR's depend on what fuel you are using. but 13.5 idle, 11.5 @ 0 boost and 10.5 under load are rediculous. thats just horse sh!t.

with your cams you should be able to idle teh motor around 14.0

0 boost under load should be around 13.5 AFR.

11.5 under boost is more than enough fuel for most cases.

that si the compression ratio...and what fuel are you running?

11-05-2004, 09:55 AM
How hard have you driven this motor? How well is it tuned? usually the first thing you need to do with a built motor is get it on a wideband and ensure that everything is righ with the AFR's. running the motor under load without enough fuel can casue the pistons to overexpand...but you have to have it loaded up for thsi to happen. it's not [QUOTE]

Didnt drive the car hard at all until at a 1,000 miles.this motor burned oil from day one when i cranked the car.The car ran a 14.7 A/F going down the road cruising and at 0 vaccum it ran a 13.5 A/F and under .5 bar it ran a 12.0 A/F.Now i did end up running .8 bar right before i pulled it back out to make sure the tune was ok for that amount of boost and ran a 10.5 A/F......so in my mind i would say that is rich.

The compression ration is 8.5:1 Ross built these piston custom to keep the compression stock.I run 93 octane here.

11-05-2004, 10:02 AM
yep...they facked up then. your AFR's were fine. did the motor have a lot of piston slap? piston slap sounds liek very slight rod knock on all cylinders. it should only be evident when cold. once warmed up piston slap should go away.

honestly man. .5 bar (7.1 psi) you could have run that motor at 13.0: afr on 93 adn 8.5:1 cr. hell i run 13.0 @ 10 psi on my own car...never had a problem. they are full of shyte...

11-05-2004, 11:55 AM
it had alittle piston slap when i first started the motor............but known after that.

On the power FC with 555cc injectors what do you set the injector % to?i have mine set 68.5% then i found the timing and fuel maps on here that you put up.But once i did that it ran real rich all the time...........Scott can you help me out with a good setting for this motor once i get fixed again.Eventually i want to bring the car to you and have it tuned

11-05-2004, 12:02 PM
not a problem man,

you can bring it to me...or you can fly me to you. either way works for me.


drop me a line in e-mail please.. ( enthalpy@tamparacing.com ) .i have some things i would liek to discuss priveately with you.