Own a 1991 Honda Civic Si and getting ready to reinstall the engine head.

Need to clean the engine block threads prior to installing new head bolts (OEM Honda).

Outside of modifying the old head bolts to use as chasers, are there any other thread cleaning chasers that forum members recommend? I found a M10x1.25 ARP thread cleaning chaser but still need to find out if its long enough to do the job.

Any advice is greatly appreciated

 

Personally I would just leave the threads alone and just wash them out with some brake cleaner then tape a small piece of paper towel wrapped around a thin long rod to soak up the residue. Removing any material is going to cause a bit of slack but probably wouldn't hurt.. If the bolt threads in smoothly with a light coating of clean engine oil after cleaning, just leave them alone.

 

Took the advice and used the old head bolts to clean up the dirty threads on the engine block.

While cleaning up the head bolt threaded openings/holes to the engine block, I noticed that the head bolt to the top left corner opening did not screw as far down as the other head bolts did (while the head is off). I assumed that all of the head bolt openings were the same depth.

I took a peek down each threaded opening on the engine block and inserted a thin rod to measure and confirm the depth of each hole. I then went to look at the engine head and noticed that the top left corner opening, is slightly elevated above all of the other openings.

I could have easily damaged the top left corner opening threads to the engine.