Valve overlap

[west coast]

Adger I have been using that page a lot of great info there.The issue i am having now i think is in the black science of designing cams that is not printed. like when to open and close valves during the stroke, how much lift during overlap, lots of variables roller versus flat tappet cam, engine stroke. I am looking to improve what i have, I have identified an issue over a year ago and looking to solve it. So understanding valve overlap and a standard on what lift and if it is tappet or valve is important with the issue I have.

Dale one other thing about the new BOSS block is it has different size head bolts also.

[SSDiv6]

Originally Posted by west coast

Adger I have been using that page a lot of great info there.The issue i am having now i think is in the black science of designing cams that is not printed. like when to open and close valves during the stroke, how much lift during overlap, lots of variables roller versus flat tappet cam, engine stroke. I am looking to improve what i have, I have identified an issue over a year ago and looking to solve it. So understanding valve overlap and a standard on what lift and if it is tappet or valve is important with the issue I have.

Dale one other thing about the new BOSS block is it has different size head bolts also.

James,

If you want make your life easier, I recommend this base software package:

http://www.controlledinduction.com/djrc.html

If you want to spend hours analyzing data, although spendy, this would be the software to use:

http://www.motionsoftware.com/Dynomation5.htm

[west coast]

Thanks Joe I knew you would chime in sooner or later, as always you have great leads to more knowledge. Congrats on retiring and moving some where warmer. you still have the same phone #? cant wait to see your car go down the track how much longer?

[SSDiv6]

Originally Posted by west coast

Thanks Joe I knew you would chime in sooner or later, as always you have great leads to more knowledge. Congrats on retiring and moving some where warmer. you still have the same phone #? cant wait to see your car go down the track how much longer?

As always, glad to help James.
As regards to valve overlap, there is a lot in writing out there.
Nevertheless, there are other details and parameters that are not taken into account.

The Controlled Induction software package is easy to use and it has been used by Crower for many years. It provides great camshaft specification based on the inputs.

Dynamotion is a more complex software package that will require a lot more details of the engine and it provides a lot of data output. Also and it comes very close to actual dyno numbers. However, unless you are building engines for a living, it may be an overkill.

Just remember, if you input bad data, the program will give you bad results.

Yep, sort of enjoying the retirement; need to keep my brains busy, therefore, I am going to either be working for a smaller local company or consulting for my previous employer.

My wife and I are enjoying the move to Glendale, Arizona, although it was 27 degrees this morning! At least, no snow and clear!

Race car is in progress and will be picking it up next month once Sean Cour is done squirting paint. Then will be busy finishing the car and getting it to the track.

Have the same number, feel free to call me anytime.

[FireSale]

James: Bolt holes are no issue. I was going to drill out the heads Brian had to 1/2 inch. Water passages are another issue, though. Going to stick with my AFR heads and run bracket. I thought SS would be fun to build for but not so much.

Good luck on your quest for answers.