Re: Dyno sheet from Mesa
 

WoW looks like you 'll have me... I'm getting scared.... well maybe not as scared as your Bravo's with 720# of torque at 3300rpm... :D:D:D

Sounds good Bob I hope you have fun.

Re: Dyno sheet from Mesa
 

congrats, impressive numbers! :drink:

Re: Dyno sheet from Mesa
 

Frankie is upgrading the XZ's to XR's

Im really not to worried though. with the kind of boating we do and the Lake that we run on, either bravo will probably be alright if the cooler stays full (know what I mean)

Besides, thats what I bought a spare drive for...... just in case

Re: Dyno sheet from Mesa
 

Bob,

Very impressive numbers. I hope that everything comes together great for you. The boat should be sweet. Still planning on hitting Sacandaga this summer? July 23rd?


Chris

Re: Dyno sheet from Mesa
 

For what it's worth:

Re: Dyno sheet from Mesa
 

Its on my calander Chris. Ill be there

Re: Dyno sheet from Mesa
 

Las,
Nice numbers. Question, you have a similar drop in torque that I have noticed in several other engines ranging from 502 to 588 CID in and around the 3100 to 3600 or so range. Do you have an opinion on what it may be?

Chris

Re: Dyno sheet from Mesa
 

Very good numbers! Some details would be great! Compression and cam would be good to know. I know some of this stuff is proprietery! :p

cstraub,
Do you think the slight dip in torque is is due to the transition between primaries and the secondaries? Just a thought. It will be interesting to hear what Laz has to say!

Craig

Re: Dyno sheet from Mesa
 

Craig,
You see that dip at various points in both N/A and forced applications I have been looking at this in many engines for some time now trying to figure the relationship in the range of the dip and the mechanical configuration of the various engines. I think it has much to do with the interaction of camshaft overlap and exhaust design. Perhaps on N/A it has to do with mild combustion chamber/exhaust imbalance at a certain frequency, and blow thru in a forced application. You see it in nearly every engine. Great numbers Laz.
Bob

Re: Dyno sheet from Mesa
 

The drop in torque you generally see on my dyno reports comes from the fact that my dyno is a manual brake system rather than a computer controlling the brake action I make the brake stop the engine the way I want and it generally does that drop because I start at a steady state RPM higher than were I want to start which is at a lower RPM generally 1000- 1500 RPM lower the reason I do it this way is because over the years I've noticed that the engines make peak cylinder pressures lower in marine engines and I want to make sure the engine will not set the det. sensor off at cruising RPM or under acceleration. It's just the way I run them for that type of testing. I always say the dyno is a tool that gives more then numbers of power and when used effectively can produce excellent results. Many people use computer controlled brake dynos they are the norm now days but I prefer this type of set up because I believe it's more effective for marine engines thats my opinion the other units also work well. It's very impressive that you saw that very few people actually notice that. Thanks for the question Laz Mesa