Interesting head info
 

Thought some folk might find this interesting from Rob at Amazon Cars.

https://youtu.be/lLXDasj3MQE?t=2372

I assume that a gas flowed head is a ported head, where the porting is based on flow bench testing. And what he seems to be saying is that it is unnecessary to port the head for a B18 & B20 street engine due to bottom end torque.

Yeah bigger valves and porting. Max HP and torque moved higher up the rpm, combine this with larger exhausts with slower exhaust gases means for the average Joe driving around town the engine is no better or could even be slower.

For my 142 I want to have low down torque and acceleration, keep the appearance of originality and not spend loads. Don’t chase max HP at the expense of low end HP. I’m not sure what that entails at this stage though. I will lighten the flywheel. I have a standard exhaust, is it worth changing, don’t know.

Rob at Amazon seems to be commenting from a rallying perspective. In the United States we don't have much opportunity to run European style rallies, but we can get out vintage cars out onto the racetrack.

I race a '59 MGA, and I have delusions about getting the PV444 out on track as well.

On the racetrack, the object is to run wide open throttle, so the power band on my MGA camshaft is 3,500 to 7,000 rpms. On that car, the exhaust gasses hit a wall just behind the valve head, and porting the head is very beneficial. I think that would also be the case for a street engine, although the porting wouldn't need to be quite so aggressive.

I have a B16 in my Volvo. When I first got it tuned, I noticed that it had a huge amount of carbon build-up in the combustion chamber. I've been running it lean in the hopes of burning off some of that stuff. But one of these days, I'll pull the head and have a look.

His point is don't waste your money on expensive head work if like me it's not a race car as it probably won't help your 0 to 60 where most of us drive the cars.

I think that's true for a lot of engines.
'Adding lightness' is usually the best place to start.

It's food for thought.

In racing you can often reduce your lap time more by improving your brakes rather than tuning the engine.

Tuning the driver is also worth the expense. :teeth_smile:

That's a very interesting vid and will probably save me a lot of money... Ill just rise the C/R a bit, clean it up a touch and fit the harder exhaust seats for unleaded.
I've raced since 1985 in Sprints and Speed Hillclimbs and going faster or shall i say winning is not one thing its a mixture of everything, Light car, good brakes, powerful torquey engine, sorted suspension, knowing how to match all those parts together and above all confidence in the car. Get it all right and then your head is in the right place to win....