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Search found 2706 matches

by Stan Weiss
Thu Sep 19, 2019 10:04 am
Forum: Engine Tech
Topic: Are Exh pushrods more stressed even in NA applications?
Replies: 35
Views: 1187

Re: Are Exh pushrods more stressed even in NA applications?

Unless I have the dynamics of the cylinder pressure decay wrong. If the exhaust valve was not to open they would still be pressure above atmospheric ABDC. (Multiple atmospheres). Also for the last "X" number of degree BDC the crank rod angle is not very favorable to generate much turning force.

Stan
by Stan Weiss
Wed Sep 18, 2019 2:23 pm
Forum: Engine Tech
Topic: accurately measuring port cross section area
Replies: 28
Views: 1078

Re: accurately measuring port cross section area

Cross section area makes sense for a straight pipe. What becomes of the effective cross sectional area when the pipe has a bend in it? My guess is this is why probing air speed is needed in relation to cross section. How effective, or accurate is probing without an exhaust stub on the port that's t...
by Stan Weiss
Wed Sep 18, 2019 10:47 am
Forum: Offtopic Forum
Topic: Race Engine Challenge scores?
Replies: 1
Views: 189

Re: Race Engine Challenge scores?

Jon, In the engine tech section Scores From The Race Engine Challenge https://www.speed-talk.com/forum/viewtopic.php?f=1&t=58526&sid=560975b89c7526a5e8c3c1dfcbcadb53 Due to some technical glitches we got off to a slow start this week. Here are the scores to date: Ben Robey, SBF, 376 cu in,Peak HP 60...
by Stan Weiss
Wed Sep 18, 2019 12:07 am
Forum: Engine Tech
Topic: Are Exh pushrods more stressed even in NA applications?
Replies: 35
Views: 1187

Re: Are Exh pushrods more stressed even in NA applications?

Why is the exhaust valve lifted less than the intake? Because, in general, low lift flow is more important on the exhaust side. In general, high lift flow is more important on the intake side. Yes, a generalization. So it is not so much that you are trying to get lower lift on the exhaust. It is th...
by Stan Weiss
Tue Sep 17, 2019 8:36 am
Forum: Engine Tech
Topic: Are Exh pushrods more stressed even in NA applications?
Replies: 35
Views: 1187

Re: Are Exh pushrods more stressed even in NA applications?

Yes. How much more? What was max cylinder pressure and where ATDC? What was CR? What was exhaust valve size? Where is EVO at?

Stan
by Stan Weiss
Mon Sep 16, 2019 4:21 pm
Forum: Engine Tech
Topic: Race Engine Challenge II
Replies: 200
Views: 15051

Re: Race Engine Challenge II

RevTheory wrote:
Mon Sep 16, 2019 3:59 pm
Do you guys know if David made it? I've been staying out of his hair.
When I spoke with David at noon today he was at the challenge.

Stan
by Stan Weiss
Mon Sep 16, 2019 3:45 pm
Forum: Engine Tech
Topic: Race Engine Challenge II
Replies: 200
Views: 15051

Re: Race Engine Challenge II

Carnut1 wrote:
Mon Sep 16, 2019 3:18 pm
I would like an update on ST as far as dyno tested this week. I am sure I am not alone. Thanks, Charlie
X2

Stan
by Stan Weiss
Thu Sep 12, 2019 3:04 pm
Forum: Engine Tech
Topic: Tight lash camshaft questions
Replies: 31
Views: 1400

Re: Tight lash camshaft questions

Still not sure what the lash ramp height has to do with lash loops. I don't know what style lash ramp is being used now, but I have not seen many constant velocity ones lately, although they do make the calculations very easy. For illustration this is a 40 degree 0.020" constant velocity and constan...
by Stan Weiss
Thu Sep 12, 2019 3:01 pm
Forum: Engine Tech
Topic: Tight lash camshaft questions
Replies: 31
Views: 1400

Re: Tight lash camshaft questions

I guess a tight lash lobe would be a constraint for someone who wanted to experiment with changing lash as a signpost re the benefit of more/less duration? Bill, I don't see why trying the lash looser would be any different between a tight and loose lash cams. Now if you want to try a tighter lash ...
by Stan Weiss
Wed Sep 11, 2019 9:01 am
Forum: Engine Tech
Topic: Tight lash camshaft questions
Replies: 31
Views: 1400

Re: Tight lash camshaft questions

I guess a tight lash lobe would be a constraint for someone who wanted to experiment with changing lash as a signpost re the benefit of more/less duration? Bill, I don't see why trying the lash looser would be any different between a tight and loose lash cams. Now if you want to try a tighter lash ...
by Stan Weiss
Tue Sep 10, 2019 11:19 pm
Forum: Engine Tech
Topic: Tight lash camshaft questions
Replies: 31
Views: 1400

Re: Tight lash camshaft questions

I guess a tight lash lobe would be a constraint for someone who wanted to experiment with changing lash as a signpost re the benefit of more/less duration? Bill, I don't see why trying the lash looser would be any different between a tight and loose lash cams. Now if you want to try a tighter lash ...
by Stan Weiss
Tue Sep 10, 2019 12:15 pm
Forum: Engine Tech
Topic: Theory of 4 valve poly quad cylinder heads.
Replies: 92
Views: 2550

Re: Theory of 4 valve poly quad cylinder heads.

Experimental study on an IC engine in-cylinder flow using different steady-state flow benches

https://www.sciencedirect.com/science/a ... 6817302582

Stan
by Stan Weiss
Mon Sep 09, 2019 12:21 am
Forum: Engine Tech
Topic: Tight lash camshaft questions
Replies: 31
Views: 1400

Re: Tight lash camshaft questions

At what lash would you call a cam tight lash?

In the mid '60s I had a SBC Engle solid roller cam which had 0.012" Intake lash and 0.014" Exhaust lash.

Stan
by Stan Weiss
Sat Sep 07, 2019 12:57 pm
Forum: David Vizard forum
Topic: The "Cocktail engine" starting to take form
Replies: 5
Views: 262

Re: The "Cocktail engine" starting to take form

I would put the 4 at 5.4 long in one bank and the 4 at 5.09 long in the other bank.

Stan
by Stan Weiss
Thu Sep 05, 2019 10:06 am
Forum: David Vizard forum
Topic: TorqueMaster cam program update
Replies: 27
Views: 1082

Re: TorqueMaster cam program update

Someone, that would be me, has been dragging their feet. I have just sent off to David and Marvin for them to checkout what hopefully is a complete install package for the 14 Day trail and all of the other files that are needed.

Stan