Long-off 340 build

nm9stheham said
- With this car and weight, there really is not any need for power brakes. And drum brakes out back of the size available work just fine. I have raced rally cars for many years with cars that had large rear drums and discs up front and never had any stopping power issues.

- The reason to go to rear discs is for cooling capacity more than anything. Drums are limited for heat dissipation, and if you are going to be using the brakes a lot (like it sounds you may be) then the rear discs may be a good idea. But, if you are sticking with stock wheel sizes, then your front disc size will be limited, and realize that the front disc size will become the heat limiting factor.

- As far as the power brakes, again, there is PLENTY of stopping power with manual brakes for this car weight. The biggest things that guys miss out on thinking of brakes it the pad material. Read up on 'coefficient of friction' and understand that if you move from a CoF of 0.3 to 0.4, then your brake torque just went up by 33% with that same pedal pressure. So you can make up a lot with simple pad selection. I can promise you if you push the pad CoF up to the 0.4 range or higher, then the brakes will likely be better than you have ever experienced.

- And, if you eliminate the power booster, then you will have a bit better to a lot better brake modulation, depending on the booster.

So I would encourage you to go with manual brakes, and do it right, and take those restrictions out of the engine equation.

So at this point there's almost an even split on power brakes and no power brakes. My main list of options is do the whole full-disc w/ power boost brakes, do power boost with just front-disc/rear-drums, or do full-disc manual brakes. I'll consider these options, but I was on the fence about opting for just manual brakes. I know they'd work fine for something light like a Datsun 510 but wasn't sure if the same is true for ~3300lbs like a Demon. If I do go manual brakes, full-disc would be the minimum.

The thumper wasn't my "choice" per se, it was just a placeholder for a cam option. If it comes down to it I'll just have to hold off til I get the car, see how a 340 does with stock cam and work my way up from there.

nm9stheham said
You need a wide torque RPM range for spirited driving in hills and mountains; you never know for sure which will be the best gear in the next turn, and a wide RPM torque range will be a big help to make up for suboptimum gearing. That calls for higher compression ratio for low RPM torque, and good breathing parts for high RPM torque.

Definitely applies since I live in the hills and it's a twisty half-hour commute to town. That situation may change, hopefully it doesn't, but that'll be my optimal driving situation

nm9stheham said
tuck the exhaust system up under the car good a tight. The last thing you want in 'spirited driving' is to go through a dip and bash the exhaust system!

That's also why I don't plan on lowering the car, and tbh I don't find ride-dropping on old cars all that appealing. Anyways yes, nothing hanging below the scrub line

nm9stheham said
Sorry, but the fan/rad combo is not all that good. Champions are not known for being particularly good. And electric fans can be OK or can be crap. It depends on the fan blade design, and the shrouding. This Derale fan does not impress me at all. The flow figures given are for free flow, and the poor fans' flow will drop into the toilet with any small restriction.....like the pressure drop of a radiator.

So put your cooling system plans on hold for now. I'd encourage you to read up a lot in the cooling system forum here.

Again, like the cam the fan and radiator were placeholders. The radiator was mainly in case the stock radiator is either trashed or missing. As for the fan my concern was something that could move decent air past the rad and actually spanned most of the radiator. From my research I gathered that, besides the differences in quality across brands, electric fans generally provided more benefit over pulley-driven. Similar flow, less power-drain and can stay spooled up when the car is sitting idle (important for summer driving).