Help Needed Please

[Girorostar]

hello everyone,

i just rebuilded my rb25det and on its first startup there was this loud ticking noise coming from the bottom of the engine, what could it be?

The parts changed on the bottom end are the pistons, main and rod bearings.

First i thought it could be piston slap but doesnt that sound go away when the engine is warming up/ get to normal engine temperature?

We used a stethoscope to listen where the noise could be coming from and it sounds the loudest at the oilpan, could this mean the main bearings arent good?

The noise its making sounds like one of those small air compressors when you're pumping a tire, and when you turn off the engine the last ticking sounds like when you hit the topsite of an empty can/barrel, like tuunk.

The parts used are CP pistons, ACL main and rod bearings and ARP rod bolts.

Could the pistons have been installed wrong?

Apart from that noise the car is idling normaly, its getting good oil pressure, no warning lights when the engine is running.

One more thing about the main bearing, the shop who sold me them sold me main bearings for rb26dett when i asked him if they would fit he said that they are perfectly fine for rb25det and that the only difference is that the rb26dett bearings have 4 extra holes and the one for rb25 has only 1 hole but the measurements are the same.

I would make a vid but i dont want to start the engine again to not risk breaking anything.

Thanks in advance for the help.

(excuse my english, english is not my native language)

[Ziller]

Does not sound good, who built the engine was it you? if a bit more detail would help.

[Girorostar]

no, i didnt build it. i dont know anything about engines,

only things i know are from this site, thats why i took it to my mechanic. he doesnt seem to recognise the sound either, says it doesnt sound like main bearing.

if theres any more info i need to add let me know, i could make a short vid tomorow if that would help.

i really hope this didnt screw up my crankshaft, dunno where i could get a knew one.

times like this i wish my car was in australia, than i could have taken it to a reputable shop.

[Ziller]

I think you should make the video, you will get more replies that way from people who could help you, sounds like a poor engine build to me.

[Girorostar]

Happy new year everyone,

My mechanic figure out what the problem was with the engine. The ARP rod bolts i bought were a bit too long so i bought new ones just incase. Had to re-size the bolts to have enough clearance. He checked if there were any damaged done, didnt see any. The engine seems to be stable and is running fine and i'm in the run-in process at the moment. Hopefuly soon i'll be hitting the 300rwkw mark or around that.