So, there has been some fruitful progress to kick off the new year and hopefully what will be the year that this engine actually gets into the car!
The current mini-project that has just been done was to have the cylinder head refreshed and to have some performance parts installed. As shown in the previous post, the Twiggy Cams were removed from the engine in the car in preparation for the work on the cylinder head.
The only other major performance parts were a new set of valve springs that are slightly firmer than the stock unit. The increased firmness and the fact that they are fresh will be important as I intend to take the engine up to 7,500 rpm. Funnily enough they came from a company called 'Performance Springs', which has the following website:
http://www.performancesprings.com.au/
The tasks done in the cylinder head recondition are listed below:
- Dismantle head
- Hot tank all components
- Bead Blast Head
- Jet wash and inspect all parts for wear and/or damage
- Check head for hardness and straightness
- Inspect all valves and guides for wear and/or damage
- Install new springs and check for correct seat pressure
- Face all valves and cut all valve seats
- Surface head face
- Vacuum test all valves
The other bit of work that was done was to see if there was anything that could be done to improve flow through the head. Most people would think that this would simply involve increasing the size of the inlet and exhaust ports, but the size of these ports is already sufficient.
Examining the valve 'bowl' the chamber just behind the valve, there is a significant lip in there which can restrict air flow. In my cylinder head this lip was removed and should provide improved volumetric flow as well as increase flow velocity (important for NA). As this was done with a CNC machine, the flow between each of the cylinders will be consistent. Hopefully this will prove its worth on the dyno
The end result is shown in the photo below:
Don't worry, there will probably be a better photo when the head gets put onto the block - which should happen soon after I get a new head gasket.
In terms of other progress, I'm cleaning up a few of the accessories and other bits and pieces while I wait for some more parts. Probably the next mini-project to get done is the modding to the valve cover to accommodate the Toyota COPs.
Hope to provide another update soon. Thanks
