A series of articles focusing on the technical aspects of building high performance VW aircooled engines. More articles to be added soon. Sign up to the JMR newsletter to receive notice of latest additions to this section of the site.
Tech Talk #11 | Project 2110: part 1 – Introduction
First in a series of articles that will cover the design and build of a 2110cc Type 1 engine. The overall aim of Project 2110 is to provide a good combination of power, torque…[more]
Tech Talk #10 | Flat cams and pitted lifters
Over the past 10 years or so there have been countless stories of high performance aircooled VW engines experiencing premature camshaft failure. It has been and continues to be a regular…[more]
Tech Talk #9 | The importance of the 3 angle valve job
First of all I’ll describe the basics of a three angle valve job: on the inlet valve, the lap marks should be placed on the outer edge of the 45° valve face. This takes full advantage…[more]
Tech Talk #8 | Does changing rocker ratio affect camshaft duration?
Cam manufacturers have no control over the style of rocker assembly being used. In order to help you dial in the cam as they intended they must use a reference point that relates directly to the cam…[more]
Tech Talk #7 | The ‘square’ engine myth
Brief version: A complete waste of time! Longer version…. a number of people have built 1745cc engines (76mm stroke x 85.5mm bore) in the belief the extra stroke as compared to… [more]
Tech Talk #6 | How much power to drive the cooling fan?
A graph of back to back belt-on, belt-off dyno tests. 2110cc bus engine, fitted with late model stock fan and standard diameter crankshaft pulley. The blue lines… [more]<
Tech Talk #5 | What effect does compression ratio have on BHP?
For maximum power output and engine efficiency, you should use the maximum CR your engine can safely handle. Major determining factor is the fuel you intend… [more]
Tech Talk #4 | Bigger isn’t always better
It may turn out the heads you have are not the best choice for good low and mid-range performance. you can’t mask a head deficiency with cam, rockers, carbs … [more]
Tech Talk #3 | Oil filter debate – reusable vs throwaway
If you want max protection for your engine DON’T use an Oberg, System 1 or any of the ‘re-usable’ billet style oil filters. Yes, they’ll show if anything major… [more]
Tech Talk #2 | What oil level with a deep sump?
For me, the whole point of fitting a deep sump is to reduce oil LEVEL inside the crankcase. You only need sufficient oil to ensure a constant supply at the pickup tube… [more]<
Tech Talk #1 | Internal case modifications
I’ve found a few things that help a lot with internal oil control and case windage. Long stroke, high rpm engines are the most problematic and stand to gain the most from…[more]