What Tech to Talk About

[DaveMcLain]

The image is 1024 X 576 pixels. I guess I could make it smaller still...

Try This:

[In-Tech]

The last two work fine here, thanky.

[turdwilly]

Cylinder head (excl Clevland/ canted valves) comparison.
I'd like to see Hp/ Tq numbers (Most interested in higher effort N/A SBF's (75000 RPM +), but even a cammed street- engine would work) with different sets of cylinder heads, All other Things kept Equal. In particular:

77219 (comp ported)
High ports TF (240 cfm out of the Box CNC)
205 Race TF (out of the Box CNC)
AFR 220 outaw (out of the Box....)

RHS

DART

Brodix
+ +
With details on flow numbers, valve size etc. on heads. Headers (With adapters when required), valve spring length/rate and else kept constant. (Down to pistons where comp should be kept constant, and piston shape changed whenever different cutouts are needed.)

Man that is extremely high effort!

[MadBill]

What, you mean the seventy five thousand RPM part?

[SWR]

What, you mean the seventy five thousand RPM part?

5000 is idle...

[piston guy]

Yes Dave that's one of the designs. There were others as well.

[David Vizard]

OK got an avalanche of stuff related to heads and some good intake testing opportunities from Dan Jones to test some of the early Ford Performance two plane intakes that have a rep for good results.

As for heads in the Windsor range I think I am up to speed with what most are asking for so, space permitting, I should b e able to cover what gets the best for the money spent.

Next chapter CAM SELECTION!!!!

Well here I am going to tell you what I am doing and see if it meets with general approval.

First there will be no vague and ambiguous recommendations like other books that are usually making/recommending poor event timing choices. Nor will there be any comments like 'if it's a serious build call your favorite cam company'. (Such statements are a cop-out by a writer who lacks the knowledge of what it takes to successfully spec a cam)

The cam section(s) will have an explanation of what and why any particular engine spec will want in the way of a cam spec so the reader will better understand the why's and where-fores here. My big block Chevy book goes into detail and with dyno results proving the essence of what I put forward. The SB Ford book will do likewise. Also it will follow with a comprehensive chart of cams that the dyno shows superior results with. These cams will be ground by a variety of manufactures to my specs and will be given part numbers specific to the book. These cams can all be ordered through one source. The reason for that is that because this one source is ordering so many cams the unit price will be less than if ordered directly from the cam grinder. Also by not ordering through the cam company you won't have to listen to some desk jockey trying to get you to buy a cam on a wider LCA because --- (pick any number of usually invalid reasons here).

The range of cams covered will be from short street spec items right through to some big street/strip cams. For serious race spec cams I will, as is my now usual habit, recommend the reader use the COS-Cam service which is proving so effective. As was suggested by some poster this is not a recommendation based on some internet dyno program. It is done on a program that I developed and wrote over a period of some 18 years and the only reason I did this was because i was not happy with the results attained by any other means including cam company recommendations.

Hopefully I cover the subject of cams to the point that it will almost eliminate the question as to what cam should be used. The way the charts are laid out a 10 year old could select the right cam without having any knowledge of how an internal combustion engine even works.

All I need to know here is will this meet the needs of enthusiast and pro engine builders??
Your thoughts here please.
David Vizard

[Walter R. Malik]

Just be sure to explain and make it clear that camshaft selection will probably be completely different for all the different air flow and cross sectional areas or raised exhaust ports, Intake to Exhaust, for the many different "regular replacement" heads available for the small block Ford.
Believe me when I say that the cam needed for a "Kaase P-38" head or the "High Port" TFS and "Twisted Wedge" head or an O.E.M. type head, even for the same type end usage, is going to be almost a completely different design.

[David Vizard]

Just be sure to explain and make it clear that camshaft selection will probably be completely different for all the different air flow and cross sectional areas or raised exhaust ports, Intake to Exhaust, for the many different "regular replacement" heads available for the small block Ford.
Believe me when I say that the cam needed for a "Kaase P-38" head or the "High Port" TFS and "Twisted Wedge" head or an O.E.M. type head, even for the same type end usage, is going to be almost a completely different design.

Trust me on this Walter - I will save them from disaster.
DV

[BobbyB]

I reread your cam chapters in "How to Build Horsepower" 2010 & " How to Build Max-Performance Chevy Small Blocks on a budget" 2009. Both books have "Overlap Selection Charts" broken down into 5 segments. This is good, but how does one really know where in the chart he desires his engine to perform? I mean, how do I know if I want the " quick street" or "fast street" or " max street" lunati cam listed in the Chevy book? The thing I think most readers would appreciate would be the ability to better understand how one cam grind will "act" versus another cam grind. I bought desktop Dyno to get a better understanding of stuff like this. Maybe a better way of saying it is, if I call Mike Jones to get a cam recommendation, how do I know I have done a decent job of describing what I hope to achieve with his cam? Does he think I want a "max street" when I really want a "quick street"? Communication is tough. You are very good at it, me, not so much.

[GARY C]

I reread your cam chapters in "How to Build Horsepower" 2010 & " How to Build Max-Performance Chevy Small Blocks on a budget" 2009. Both books have "Overlap Selection Charts" broken down into 5 segments. This is good, but how does one really know where in the chart he desires his engine to perform? I mean, how do I know if I want the " quick street" or "fast street" or " max street" lunati cam listed in the Chevy book? The thing I think most readers would appreciate would be the ability to better understand how one cam grind will "act" versus another cam grind. I bought desktop Dyno to get a better understanding of stuff like this. Maybe a better way of saying it is, if I call Mike Jones to get a cam recommendation, how do I know I have done a decent job of describing what I hope to achieve with his cam? Does he think I want a "max street" when I really want a "quick street"? Communication is tough. You are very good at it, me, not so much.

This is why me and others have wanted to know engine vacuum in relation to overlap. Also at what point is vacuum to low to operate power brakes? I have a Pontiac 400 Vizard speced cam with a small shot of nitrous in mind, I am very happy with it, it's very drive able and responsive beyond my expectations it pulls 13" vacuum (could get more with a few changes) and no problem with power brakes????????

[David Vizard]

I reread your cam chapters in "How to Build Horsepower" 2010 & " How to Build Max-Performance Chevy Small Blocks on a budget" 2009. Both books have "Overlap Selection Charts" broken down into 5 segments. This is good, but how does one really know where in the chart he desires his engine to perform? I mean, how do I know if I want the " quick street" or "fast street" or " max street" lunati cam listed in the Chevy book? The thing I think most readers would appreciate would be the ability to better understand how one cam grind will "act" versus another cam grind. I bought desktop Dyno to get a better understanding of stuff like this. Maybe a better way of saying it is, if I call Mike Jones to get a cam recommendation, how do I know I have done a decent job of describing what I hope to achieve with his cam? Does he think I want a "max street" when I really want a "quick street"? Communication is tough. You are very good at it, me, not so much.

This is why me and others have wanted to know engine vacuum in relation to overlap. Also at what point is vacuum to low to operate power brakes? I have a Pontiac 400 Vizard speced cam with a small shot of nitrous in mind, I am very happy with it, it's very drive able and responsive beyond my expectations it pulls 13" vacuum (could get more with a few changes) and no problem with power brakes????????

This post has promoted me to put the expected vacuum (assuming good ring and valve seal and typical internal friction/pumping losses) that will be seen by any given displacement, CR and cam spec in current and future books. Thanks for feeding me the idea.

DV

[BobbyB]

David, your printer/publisher has the ability to show several colors on the same graph. For example, in your Cylinder Head Flow Test book, your show, tq & hp, for a 306 (as I recall) with 170 cc dart heads, 190 cc heads & ported 170 cc head. This graph is very easy to understand and informative. What if you graphed tq, hp & manifold vac, for all the lunati hyd flat cams from the chevy book for say a 350? Except do it for a 302 or 351 ford of course.

[novadude]

This is why me and others have wanted to know engine vacuum in relation to overlap. Also at what point is vacuum to low to operate power brakes? I have a Pontiac 400 Vizard speced cam with a small shot of nitrous in mind, I am very happy with it, it's very drive able and responsive beyond my expectations it pulls 13" vacuum (could get more with a few changes) and no problem with power brakes????????

I suspect this Pontiac cam is on a tighter LSA? Better not tell anyone on the Pontiac forums, as many there think old school lazy lobes on a 114 LSA is the only way to Pontiac performance nirvana!

[GARY C]

This is why me and others have wanted to know engine vacuum in relation to overlap. Also at what point is vacuum to low to operate power brakes? I have a Pontiac 400 Vizard speced cam with a small shot of nitrous in mind, I am very happy with it, it's very drive able and responsive beyond my expectations it pulls 13" vacuum (could get more with a few changes) and no problem with power brakes????????

I suspect this Pontiac cam is on a tighter LSA? Better not tell anyone on the Pontiac forums, as many there think old school lazy lobes on a 114 LSA is the only way to Pontiac performance nirvana!

Yes it's a 268/222 276/226 on a 108 installed on a 102,my reason for wanting to run nitrous was based on my disappointment from my earlier experience with a "Pontiac" specific cam shaft on a 113 LSA, after my initial test drive I doubt I will ever run nitrous on it, it's already traction limited and there is still tuning to be done. It's a 4sd with a 3.42 gear and there is no need to side step the clutch.