Tweaks to low power engines

[noise boy 2]

Originally posted by avsfan733
order of payoff: (as far as im concerned)
compression
cams
internal lightening (rods pistons crankshaft)
porting
blueprinting (sometimes includes above)

also look other places besides the engine such as the transmission flywheel (the lighter the better unti la certain point) and just straight up tuning of the engine such as fuel air and ignition but those are prolly obvious ones

Car craft magazine did a story on compression ratios and their effect on power using a 440 chrysler big block and a pile of copper head gaskets. They started at 11:1 and dropped all the way to 8:1 by stacking head gaskets up. What they discovered is that a single point of compression is worth about 3-4% gain in hp. Not really a whole lot of HP for the potential hassles. What this did not address was the effect of cam timing and overlap on the power produciton. On a High static compression engine, you can generally get away with more cam overlap, as the cylinder pressure is already high, and the result will be moving the powerband up higher in the rev range. With a lower compression engine you want to have less overlap (larger Lobe displacement angle) as you need the cylinder pressure that you are not getting with the low static compression ratio. If it were me I would look at the intake and exhaust tracts and the cams first, the largest gains are to be had there. The trick is that the three are all inter-related, if you increase the duration of the cam, you should have already upped the flow potential at the intake and exhaust parts, or the potential gain will become more of a loss as the powerband will shift up the revs, without generating any more power. Compression is really limited by available octane rating for the series. The lightening of the reciprocating assembly would help, but more to allow the engine to rev quicker than to build more power.

[Dani Filth]

Originally posted by Ntrprise
I've spent the last 18 months designing a 750 Formula car. The league is intended for people who want to design / build and race their own cars.

i would like to know what would be the cost of a full 750 formula car .. and also the cost of the chassis .. without the engine

[imull]

have a look on the 750mc site.

Its a couple of years since i finished with the car but there used to be a for sale list on the site...

[Ntrprise]

Originally posted by Dani Filth
i would like to know what would be the cost of a full 750 formula car .. and also the cost of the chassis .. without the engine

I'll let you know when I'm done!

It is relitivly cheap. I spent About £60 on all the metal required for the chassis. Designing and building this will keep you busy for a few months.

On paper, you can have a car for about £4k or even less if you are concentrating on the budget. There are some things which make the price jump but are not completly necessary, like data logging equipment. 2nd hand 1 can be brought for anything between £4-12k I guess.

It is worth takin a look at this league. Considering the cost, these cars are pretty damn quick! This is a great grass route league and the people who race in it are so helpful.

There is a book about it, if you want to know more: amazon.co.uk/exec/obidos/ASIN/1852604476/ref=sr_aps_books_1_1/202-5035820-7031061

[Dani Filth]

i was wondering if this type of car can be used in hillclimb races ???