Fiat 1800 Head Rebuild

[divace73]

is that a beehive spring??

[Daniel]

yes

[divace73]

yes

buzz buzz, I imagine having 1 spring instead of 2 is an advantage on the cams, in real terms what are the advantages, are they worth the investment, I am thinking of getting some??

[Daniel]

i havent perfected it yet to be able to say 1 size fits all so i can't give u an answer, I've been really busy for a while
now things have slowed so maybe i can get an back on this.

[BEEK]

yes

buzz buzz, I imagine having 1 spring instead of 2 is an advantage on the cams, in real terms what are the advantages, are they worth the investment, I am thinking of getting some??

wonder why NASCAR who can use almost any technology uses 3 springs on the valves instead of 1, they use titanium valves, with 6.6mm stems, titanium retainers, copper beryllium seats. all the best money and millions of dollars of research can provide. if behive single springs were the answer wouldnt they use them? just a thought. also we didnt go formula 1, as compressed air valve actuation is not in the relm of possability for your cars

[Daniel]

yes

buzz buzz, I imagine having 1 spring instead of 2 is an advantage on the cams, in real terms what are the advantages, are they worth the investment, I am thinking of getting some??

wonder why NASCAR who can use almost any technology uses 3 springs on the valves instead of 1, they use titanium valves, with 6.6mm stems, titanium retainers, copper beryllium seats. all the best money and millions of dollars of research can provide. if behive single springs were the answer wouldnt they use them? just a thought. also we didnt go formula 1, as compressed air valve actuation is not in the relm of possability for your cars

Maybe it's a reliability issue having a couple spring to get you back into the pits if 1 gives way hear the engine
floating a valve or the nascars run rather larger valves and 1 spring might be to much to deal with how about rules
they can be pretty tight regulations??? just guessing i haven't a clue. I do know that my retainers, titanium valve pins
and springs are a lot lighter then stock combined weight.

[BEEK]

having built a few sb2.2 for arca, the only difference from a nascar motor is arca can run a roller cam. There is quit a bit of seat pressure for a roller cam, the valves that we ran even though they were 2.06" diameter head, they weigh less than a standard fiat valve (titanium). honestly we were not worried about reliability beyond the lack of failure. if the assembly failed it did not matter if it made it back tot he pits or not. we did break a few valve springs over the years, i attribute that to over reving the engine (missed shift) or (lack of traction, spinning or having the rear wheels lifted off the ground). honestly i followed suit of all the major and minor engine builders and the camshaft manufacturers who specify spring rates and seat pressure. i do notice american manufacturers using beehive springs on production motors, im sure it is for the exact reason you specify, to reduce valve train weight and increase reliability, but i feel it is for production car not race car applications. having said that, i have had customers want and ask for beehive springs on their performance street car and saturday night special v8 vehicles. as for a fiat application, im interested, and by no means saying it is bad or wont work. the other consideration is rpm, the arca engines run 9500 rpm all day, where the fiat engine might see 7k for a few seconds during a shift.
in my fiat race cars i ran springs made by isky (never had a problem), international autoparts, (had a few break) and oem, (never broke one but did have float over 7k). i ran my engines from 5500-7500 for hours on end.

[Daniel]

Depending on what engine you run the rpm can be up there as well, I heard of someone running a 1438 up
past 13,000 rpm during a race then a rod let go. 1800s can do 9k without any issues if the rods are shot
peened and seems removed on the sides. Thats what i've done on stock rods.

I'm surprised you had valve float over 7k on a fiat engine I've never had that problem were you running the
isky springs?

[BEEK]

float was on oem springs, i was turning 2.0l 9k on stock rods. i had a few break and go thru the side of the block, but all were oiling issues, not metal fatigue. i had a serious problem with oil areation and starvation