Here's an update on my top-end rebuild of my '87 CRX Si (D15A3 engine). Valves all measured in spec and head and block are flat and unwarped. The head is already below the service limit for resurfacing/decking. One of the previous owners must have resurfaced the head before. I'm just going to install new gaskets and seals and call it good.
There are just a few changes I've made while I'm at it that will hopefully improve performance. I cleaned all of the carbon out (the exhaust valves were really coated) and cleaned the valve seats. I've ported and polished the exhaust ports and the top portion of the intake manifold. I also ported the top butterfly area in the throttle body (it's pretty restricted). I need to still smooth out the intake ports a little (remove burrs) and polish the combustion domes in the head. So flow should be better with little invested cost (just time and Dremel bits). I've also purchased a throttle body from an 86-89 Integra. It looks like it should bolt up with a custom spacer plate. The TPS is exactly the same as stock and the butterfly looks much bigger than stock. I don't have it in my hands yet though, I'll know more when I do. I'll probably install the stock TB for now and see if there was any improvement from the porting I did. Finally I'm hoping to order the Web 35-060 cam and AEM cam gear soon. I found out that OBX also makes a cam gear for the 1st gen CRX. It's cheaper than AEM, but I think you get what you pay for (gears aren't hard anodized on the OBX). So.....with some head work, bigger throttle body, cam, cam gear, header, exhaust, intake, and ignition it will be real interesting to see what this engine can do. Last year I had 100 hp at the wheels without the head work and TB. I'll know more shortly when I get her buttoned up. Kirk B. '87 CRX Si
