Engine Conversion in progress

[Hibrydsoul]

So I've gotten frustrated with how slow the original engine was not to mention how expensive parts were for it in my country.... that I've decided to change the engine. I'm putting in a GA1500 engine in it.... So far we've gotten the engine mounted.... just for the electrical and the exhaust systems to be done now... no major modifications were needed to be made save and except the brackets for the mounts on this engine were fabricated of course. so except for a SOHC 1.5 8V I now have a DOHC 1.5 16V... can't wait to test this puppy out... Oh yeah one more thing... I also had to re-outfit the trans-axle as well. I'll post pictures when it's done if you'all are interested.... so reply and then I'll post once its done.

[aveodude]

Never thought I would say this but it makes me grateful for my 1.6 16V. I didnt think cars got any slower.

[deniswhite1]

Lmfao

[acdc1287]

how much power gains could you get with dual cams opposed to a single cam. i know that having 2 sets of cams increases airflow in the cylinder.

[aveodude]

That is not how that works at all.

[acdc1287]

i ment to say, having 2 cams increases the valve count in the cylinder to 4, which allows more air to go in and out of the engine

[aveodude]

Just because there are more valve, does not mean there will be more air. Port shape and size means more than number of valves.

[petrified.rabbit]

generally the size of the two valves instead of one increase the flow into the cylinder by 20-30%

but that is just the valve opening, and at the same height and duration. When you factor in the ports, cams etc. there is more to power than just extra valves.

having said that, usually (in a vw at least) the 2.0 8v to a 2.0 16v is about a 30 hp increase.

[aveodude]

generally the size of the two valves instead of one increase the flow into the cylinder by 20-30%

You cant make that kind of generalization you know EVERY instance where you can go from 1 to 2 valves. Just because you increase the number of valves, does NOT mean that the cylinder will be getting more air. That is like saying 2 turbos will ALWAYS provide more air than 1.

I am not saying that in this specific instance it will not be that way. I am just saying that you cannot make that generalization unless you have flow tests proving it.

[petrified.rabbit]

did you not read this part?

but that is just the valve opening, and at the same height and duration. When you factor in the ports, cams etc. there is more to power than just extra valves.

two engines from the same manufacturer ( i used vw, ABF and ABA engine codes):
if you take a single intake valve from a 2 v per cylinder engine, and and measure it.
then take the two intake valves from a 4 v per cylinder engine with the same bore and stroke, and measure those.

the surface area of the two valves will be greater than the surface area of the single valve by 20-30% which means (i am not looking for the equation) that the flow from the opening(s) will be greater if the lift and duration are exactly the same.

simply, if you have a 6 inch cylinder bore, then up to half the diameter (or radius) could be the diameter for the intake valve. so you could have a 3" valve. But due to the double cross sections on the same bore you would only be able to fit 2 2" intake valves.

BUT 2 x 2(pie)(squared) > 1 x 3 (pie)(squared) <- not accurate depiction of formula

with 1" of lift for 180(degrees) the cylinder can draw in more air through the opening.. the porting of the head and all that stuff is not factored into that.


2 x 2(pie)(squared) x 1" /180(degrees) > 1 x 3 (pie)(squared) x 1" /180(degrees)<- not accurate depiction of formula


2 x 2(pie)(squared) > 1 x 3 (pie)(squared)