Horsepower chain book

[bytor]

OK the key here thats obvious is that were talking about a MAX potential power range and your use of 14.7:1 compression , and trying to maximize the TORQUE CURVE at 6000RPM , all thats correct for a race engine, but far higher in the rpm band than any street driven car engine would be using. keep in mind max realistic durability would be near 4200 feet per minute in piston speed and you would not want to reach 4500 feet per minute for more than a few seconds if you wanted the engine to last very long even with good aftermarket components, in most cases the torque peak on a race engines going to fall about 800rpm-1500rpm lower than the power peak and you don,t want to exceed the piston speed limitations.
with a 3.625 stroke your looking at a 6000rpm torque peak and about a 7000rpm power peak where a 14.7:1 compression engine would use a cam with near 270 duration, and a cam LSA in the 106- 108degree range

This sample is from the book. My actual build data is rod=6”, stroke=3.75”, compression 10.4 and my 233 @.050 cam puts my peak torque around 4000RPM. I looked at the piston speed as well with the build data in the example. It didn’t look realistic to me either. The CD that came with the book has a piston speed Excel workbook included but it only calculates max piston speed not the mean piston speed like Indy’s workbook does.

keep in mind ALL OF THIS this advice seems to be directed at use of a drag race engine, NOT a road race or street driven combo and certainly not daily transportation, or an engine running pump octane gas limitations, in that limited context, the info may be valid. Yes with a drag race engine , where your under high rpm stress for only a few second and reducing the drag on the engine could potentially give you a few hundredths of a second advantage. on most performance street engine builds youll be trying to maximize the torque curve and ideally maximize the power curve in the rpm band youll actually use on the street, making a 4000rpm-5000rpm torque peak and a 5500rpm-6000rpm power peak on a 383-406 SBC, or a 454-496 BBC much more realistic

I agree, what invalidated disabling the alternator field for me was the comment about ignition boxes. "Now, a BIG down side to this is if you have a high energy ignition system, ESPECIALLY something like an MSD box! Those boxes need full power to function properly. If you try this alternator trick when you have anything other than an old points type ignition system you'll end up LOSING power because the poor ignition system isn't going to like it. The battery alone is barely enough to run an MSD system."

 

[busterrm]

Busterrm, any more thoughts on the book?

One of the calculations from the book I have been playing around with is the OptCam. Based on bore, stroke, CR and RPMTQ your supposed get an indication of the right intake can duration @ 0.050 you should use. I used the variables for my build and it calculated out to 256 @ 0.050. When planning my build using desktop dyno and Grumpy's famous cam sizing chart, an intake duration of 233 @ 0.050 was the sweet spot recommendation. Now I have not gone back and double checked my math but it seems off a bit. Here’s the section from the book.



One of the other comments I found interesting was in the Friction chapter. In the recommendations section it talks about "switching the alternator field off at full throttle." Grumpy, whats your thoughts on this advice?

Links:
http://www.badasscars.com/index.cfm/page/ptype=product/product_id=101/prd101.htm
http://www.pirate4x4.com/tech/billavista/Wiring/Part2/

Well its hard for me to say that there was any one other thing that was useful. There were many things I have always misunderstood. Mostly for me the "practical advise and chapter finals" were most helpful to me.

 

[busterrm]

The book is on its way to then next one on the list.

 

[87vette81big]

The Horsepower Chain Book showed up in my Mail too
Will read and post questions for Grumpy & others to answer.
Keep us all thinking.

 

[bytor]

Who's got the book now? Just curious.

 

[87vette81big]

Who's got the book now? Just curious.

I am guilty of not finished reading Bytor.
Got busy with projects.
Father in Law was here.
Newborn son Jamie .
Helping others answer questions on DC & here.
Try & finish both books this week.

If it covered more than SBC & BBC like Pontiac, Olds V8, Fords too I would have finished in 2 nights.
Read many Chevie books prior.

 

[bytor]

No worries 87vette81big, just checking in.

 

[Indycars]

I am guilty of not finished reading Bytor.
Got busy with projects.
Father in Law was here.
Newborn son Jamie .
Helping others answer questions on DC & here.
Try & finish both books this week.

If it covered more than SBC & BBC like Pontiac, Olds V8, Fords too I would have finished in 2 nights.
Read many Chevie books prior.

If I'm next on the list, take your time Brian. I'm not going to have time
for another month. Take care of the future hotrodder we will
need him to carry on the where you left off. Have you put a steering
wheel in his crib yet?

Who is left on the list?

 

[Indycars]

Who has the book now, if I'm next on the list I'm ready now.

 

[philly]

i have this book and really think its worth about the $20 that each of you guys put in to score it. i paid the full hundred bucks for it and really think i overpaid, there arent alot of detailed explanations of ways to in fact make power, its more like a long drawn out explanation of the ways they compute power with the software, which may or may not be flawed. i dont know.

 

[Indycars]

Sounds like an honest opinion Phil. I don't think anyone so far has been real excited about it, but not quit such a low rating as yours.

I like numbers and I think with the AQ1 from AEM that measures acceleration, there should be a way to calculate HP from information that I can log. I'm hoping this book might help with that. Do you have any insights into this since you have read the book?

 

[philly]

ill have to read it again, i read it while i was in kuwait last march or so and ive been putting it off as i expand my library because i disliked it so much the first time, i almost feel like i didnt read it right or something... like i missed somethin in there. harold bettes makes reference to that book in his book about engine airflow... and i think harold bettes is a MF genius so maybe im just not smart enough to read between the lines of the book and find the hidden meanings? ill run through it again one of these days and maybe get more from it than i did the first time.