Weber DCOE Tuning Questions

hiperfauto said:

The numbers I used assumed you had the VV101 cam. The calculator says to use seat to seat valve timing numbers for best results but the closest I could find were valve events @ .020" lift using this site for reference. That means that dynamic compression is actually a bit lower.

Using the numbers for a VV71 it works out to 8.90:1.

Click to expand...

Yep that's my favorite calculator except that everything is in some units made up based on a mythological kings thumb ferfawkssake.....

What's nice with that is you can keep banging in numbers till you get dynamic up to high 9s maybe 10:1---then see whatchoo need for "static" to get that number.

Well now that's quite handy, thanks!

I got the rod length wrong. It's 5.7" not 5.71" but it made no difference in the calculation.

Edit:

Then again maybe not. 6 bolt crank rods are 5.7", 8 bolt crank rods are 5.713".



Looking at the specification books again it's just a conversion error. They're both supposed to be 145mm.

Ah okay, I was missing the seat-to-seat part of that.

I'm going to do a little more research and come up with a plan. The owner from the PNW says the car definitely had the vv101 in it when he sold it (he pulled a vv71 out to put the vv101 in) and he also said the guides have been cut down, but not the spring seats, for clearance. I wonder if that extra little lift on the U cam would cause issues there... If I can get away without pulling the head and machine work for the time being that would be ideal, I'm sure the motor will need a refresh in a couple of seasons anyways.

I setup my 45 DCOEs last night for what I think will be ball park settings based on multiple other setups that are near my engine. I'll report back with numbers as soon as I have them. Specs as follows:

37mm chokes
150 main
200 air
60 idle
200 needle/seat