So I just swapped the motor out of my previous 91 teg into my 93 teg. I swapped over the exhaust and intake manifolds with fuel rail from 93 teg. I put in new spark plugs that I had bought for my 93 motor but didn’t install. Then I heard that 90-91 plugs are different from 92-93 plugs, so I went to autozone’s website and confirmed this.
I’m wondering if this is why I have a loud lifter noise in the motor when it’s running. I was wondering what makes the plugs different? I thought the blocks are the exact same 90-93. What determins which plugs to use? Should I get 91 plugs because it’s a 91 motor, or keep the 93 plugs in bc I have the 93 intake manifold, exhaust manifold, fuel rail, distributor, and wires? Thanks in advanced for responses.
You probably need to adjust your valve clearances. There is no way spark plugs could contribute to any kind of mechanical noise unless your pistons are hitting them (which is not happening).
This chart defines the characteristics of NGK spark plugs based on the part number.
Essentially, the difference between the 90-91 and 92-93 is a “projected insulator” vs an “extended gap”, respectively. However, this page refers to the 92-93 as “projected insulator”.
This page talks a little bit about spark plug tech (of which I know nothing) but basically what you can take away from it is that as long as you won’t have any clearance issues, you should use the plug that your computer is designed for.
So to sum all of that up, the 92-93 plugs are probably best for your application even if the 90-91 engine doesn’t have the exact camshafts that your 92-93 engine had (or at least that is what I remember from 10 years ago).
Plug choice should have no audible effect on your motor, unless it was misfiring. As buymysoul said, it probably just needs a valve adjustment
My tuner always tells me that the NGK BKR7E is the best plug for a Honda motor, from stock up to 700whp. I don’t know if it differs for an obd0 motor/ecu, but I wouldn’t think so. As said above me, get the plugs for which computer you’re running… But if possible I would get the BKR7E or the NGK 4644 (same plug, they just don’t make the ‘BKR7E’ anymore)
Thanks for the advice and information…i’m going to look over the material later tonight when I have more time, but I think right now i’ll keep the 93 plugs in since pretty much everything bolted to the motor is from my 93 minus the cams which i guess are different. I think I’ll also just double check that the timing is on and will also check and adjust the valve clearances too.