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Search found 459 matches

by Ken_Parkman
Sat May 08, 2021 3:31 pm
Forum: Engine Tech
Topic: Cooling fan shootout - Engine Masters
Replies: 75
Views: 2190

Re: Cooling fan shootout - Engine Masters

The explanation that makes sense is there if you use your math skills. Take that self same fan and spin it many times outside of its design point at a power cubed factor and see how the math works out. Yes 30 hp is absurd - that is the point. I also find it also absurd that people will kill themselv...
by Ken_Parkman
Thu May 06, 2021 12:15 pm
Forum: Engine Tech
Topic: Cooling fan shootout - Engine Masters
Replies: 75
Views: 2190

Re: Cooling fan shootout - Engine Masters

Problem is a mechanical fan is engine driven, and engine rpm is not particularly related to the cooling requirements. So you have to have the fan effective for your worst case cooling condition, and it may be wildly wrong for the best case cooling condition. A fan designed to work at hot idle in a t...
by Ken_Parkman
Mon May 03, 2021 8:45 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 71
Views: 1640

Re: I Still Like Pushrods, They're Still Viable

The ST6 is actually Canadian, Pratt & Whitney Canada.
by Ken_Parkman
Fri Apr 30, 2021 2:19 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 71
Views: 1640

Re: I Still Like Pushrods, They're Still Viable

Back to the pushrod discussion One excellent combustion chamber variation that has been not included in the discussion is the rotated canted valve that is so successful in many forms of racing. I'm led to believe but do not have the data to back it up that NA it exceeds the BMEP of F1; not sure if t...
by Ken_Parkman
Mon Apr 26, 2021 3:15 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 71
Views: 1640

Re: I Still Like Pushrods, They're Still Viable

Almost always racing has a displacement limit, so there pushrods are bad; certainly F1, so it is a no brainer there. It is cool how to see advanced design and technology addressing the packaging disadvantage of OHC/DOHC, and conversely addressing the rpm range limitations of pushrods in Nascar/PS un...
by Ken_Parkman
Fri Apr 23, 2021 4:55 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 71
Views: 1640

Re: I Still Like Pushrods, They're Still Viable

My 2011 Ram is pushrod and has VVT, variable inlet runner length, and cylinder deactivation. In 200k of serious abuse the only problems have been a rad hose clamp broke and exhaust manifold stud breakage, one each side. In general it has been terrific and I am quite happy with it. But it is a seriou...
by Ken_Parkman
Thu Apr 22, 2021 12:53 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 71
Views: 1640

Re: I Still Like Pushrods, They're Still Viable

The point of the Porsche article was in support of pushrods as in some cases a superior technology. Obviously in aircraft weight and packaging are ultra critical so this is an extreme example, but the point is relevant. The "high tech" OHC engine could not make up for the pushrod advantages. The OHC...
by Ken_Parkman
Tue Apr 20, 2021 8:08 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 71
Views: 1640

Re: I Still Like Pushrods, They're Still Viable

http://www.seqair.com/Other/PFM/PorschePFM.html Here is an article from the airplane engine thread that really deserves to be read in context of pushrods. Porsche spent 75 million to make a "high tech" OHC aviation engine and managed to double the specific output of the pushrod engine it was suppose...
by Ken_Parkman
Sun Apr 18, 2021 9:45 am
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 71
Views: 1640

Re: I Still Like Pushrods, They're Still Viable

I do find it interesting that all 3 major North American manufactures tooled up for OHC V8 engines, and all 3 have gone back to pushrods. It simply is a better design in a V configuration, reduced parts count, compact, good power density, better packaging, lower hood line, better aerodynamics etc et...
by Ken_Parkman
Wed Mar 24, 2021 1:24 pm
Forum: Engine Tech
Topic: AMC cylinder head project
Replies: 4
Views: 467

Re: AMC cylinder head project

Here is a picture of the deck side, and you can see the head bolt pattern better. URH deck side.jpg Good catch on the head bolts - that was a huge design problem. The stock head is siamese port, and obviously the bolt pattern is designed for that. The change to symmetrical was a big issue on the exh...
by Ken_Parkman
Tue Mar 23, 2021 9:27 pm
Forum: Engine Tech
Topic: AMC cylinder head project
Replies: 4
Views: 467

AMC cylinder head project

Just thought I would post a pic of a project I have been collaborating on with Kevin Fontenot. I'm design, and he is manufacture. There is really little justification to this other than to see if we could do it. It has been a lot of fun, certainly some grief, and a hell of a learning exercise. URH I...
by Ken_Parkman
Fri Mar 19, 2021 2:07 pm
Forum: Engine Tech
Topic: Hit Water
Replies: 31
Views: 1720

Re: Hit Water

Although I had a set in from a hot rod being driven only a few hundred miles a year, and the exhaust seats were sunk so bad the valve was seating on the flat backside of it's head. Rather remarkably it ran quite well like that. At the same time another set of the same casting number from a relativel...
by Ken_Parkman
Wed Mar 17, 2021 7:24 pm
Forum: Engine Tech
Topic: Future of head porting
Replies: 199
Views: 9673

Re: Future of head porting

Poor guys. They use PLM
by Ken_Parkman
Mon Mar 15, 2021 3:12 pm
Forum: Engine Tech
Topic: Future of head porting
Replies: 199
Views: 9673

Re: Future of head porting

One question I have been wondering is what type of CFD do you use, 2 phase flow or single. I was not under the impression that 2 phase is sufficiently advanced yet, at least anything I have been involved in is not. However it is clear there is lots to learn, and it is not intuitive.
by Ken_Parkman
Sun Feb 28, 2021 9:52 am
Forum: Engine Tech
Topic: 3D printed inconel header
Replies: 19
Views: 977

Re: 3D printed inconel header

Another cost to think of is the amount of powder. Even if most is reclaimed, you had to buy it in the first place. And the amount and cost for a big part is scary. But for development hardware it is absolutely fantastic - fast and relatively cheap considering. But the machine on time is just too muc...