Never heard that. Most people I see doing it hold it steady. They do vary the rpms when trying to seat the piston rings.

 

as a matter of fact…. I did.

 

What information did that calculator ask for?

Ive been playing around with headgaskets myself trying to bump my compression to 9.5:1 but there is quite a bit of information one has to put in to get static and dynamic compression. Just be careful cause Ive seen some calculators be very simple and not ask for important information to calculate the compression.

 

Here’s what all it asks for.

 

So you should have good accurate information it asks everything that good calculators ask.

I myself am currently playing with different head gaskets not sure what to get trying to get my quench down as well as get my compression to my goal of 9.5:1. Currently if I stick with FelPro like I want to my quench will be between 0.0455" to 0.049" which is outside the range of 0.038" to 0.043" for ideal. I found bunch of Cometic MLS gaskets that I am unsure about myself but I can get a 0.035" compressed thickness to get me at 0.0415" to 0.043" but that only puts me to 9.37:1 to 9.41:1 compression where I can just stick with what I currently have 0.041" giving me 0.0475" to 0.049" quench and 9.23:1 to 9.27:1. I cant justify spending $180 for a pair of Cometic MLS gaskets to see a 0.14:1 increase in compression.

For mine dynamic is 7.06:1 to 7.09:1 depending on what my actual deck clearance is. That is also using advertised timing events which I dont agree with cause my cam is a roller cam and using advertised events gives me a overlap of 58* but when using this interactive camshaft tool I found online that uses valve timing events @ 0.050" along with advertised it is showing my valve overlap is actually -4* due to the quick ramp rate of the roller lifters the valves open slightly for a period then quickly snaps open to full lift where calculators else where is not taking this super quick ramp rate of roller lifters into account.

Why I am driving myself crazy with calculators trying to figure out where I need to make tweaks here and there to reach my goals.

 

I understand, I spent an easy two-three weeks running through various calculators trying to find good ones then pulling and inputting all the various data I needed to build everything up so I have a good static compression, all while trying to ensure that I would also still maintain clearance etc. the added benefit is it took a 183hp stock engine up to 300+ all while still basically engineering it to improve its fuel economy.
The blessing about it eating itself previously is that I learned a lot, and finally figured out why I was only ever able to get 9mi/gal on the highway at 65mph!

Never made sense to me why I could never get better than that especially when guys on here with 4x4 big blocks would get 15 or better while towing. Oh the joy of barn finds someone else found and did a quick flip on… smh some people just don’t have any appreciation for older vehicles…

 

Thats the thing with calculators. I have DD2000 that I use for my build and I refuse to use the compression ratio calculator. Something is wrong with it cause punching everything in including 8cc for the volume above piston for the 8cc valve reliefs on my flat tops it states with 0.0065" deck clearance will give me 9.57:1 compression. If I change the deck clearance to 0.008 which is more distance between piston and deck for some reason my compression goes to 9.61:1 which makes no sense considering all other calculators Ive used online shows 9.23:1 @ 0.008" and 9.27:1 @ 0.0065" which is how it should read.

Another problem I am running into is the cam calculator on DD2000 I have, if I punch in the @ 0.050" cam timing specs the lobe center angle is incorrect. My cam is a 112* but this cam calculator likes to show its 109.5* with the intake centerline correct at 107*.

Its why I am very wary of calculators but with what I have done so far I am seriously thinking about ordering 0.039" felpro gaskets over the 0.041" I bought as it was recommended by AFR. Just wished they would offer more options for headgaskets.