REEDER HC head engine knock

[John Dow]

Hello Everybody!! I have a Reeder aluminum high compression head on my '23 Touring that is prone to engine knock. I only use 91 octane gas and keep the ignition as retarded as much as possible to avoid the knock. Recently it seems the knock is becoming more prevalent and louder. Is it possible carbon build up in the chambers could be the cause? If so how would be the best way to remove it? Thanks!

[Allan]

I'd be checking rod/main bearings. I never had any trouble with the Reader head on my speedster other than warping between cylinders 2 and 3.

Allan from down under.

[John Dow]

Thank you Alan. I've checked and re-checked all is well in that department.

[rondupree]

Yup. It's the "Reeder Rattle". More than one of us had the same problem. On my engine I only had a narrow range of timing adjustment where the car ran like it should, and didn't have a light combustion knock.

[Rich Huggins]

Piston hitting the head i found that my high compression pistons were just kissen the combustion chamber

[Norman Kling]

Depends on what your call a knock. A spark knock sounds like a Ping and will change with the position of the spark lever. A dull thud would be caused be something like a piston hitting the head or a piston loose in the cylinder or possibly a loose main bearing. This type knock is also more noticeable when under power such as rapid acceleration or hill climbing. A rod knock is like a rattle which becomes loudest when the engine is neither pulling nor slowing on compression. Usually hear when you are on a level area with the gas just slightly slowing down. It will vary if you give it just a bit of gas or just a little less gas.
Norm