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Search found 3301 matches

by David Redszus
Mon May 10, 2021 4:24 pm
Forum: Engine Tech
Topic: Helping air around a curve?
Replies: 8
Views: 480

Re: Helping air around a curve?

Definitely interesting to think about theoretically ideal shapes; could image the time and skill required to actually port in such a shape or what would be required to actually manufacture such a shape in a curved runner like that. CFD is the perfect tool for the design of optimum shape induction t...
by David Redszus
Mon May 10, 2021 4:15 pm
Forum: Engine Tech
Topic: 95 RON standardized as new high octane?
Replies: 18
Views: 526

Re: 95 RON standardized as new high octane?

Fuel with ethanol in it INCREASES FUEL CONSUMPTION. you have to buy MORE OF IT. Yes, the addition of any oxygenate will lower the stoich value and will require more fuel for a given air/fuel ratio. Vehicles that operate on 91 octane gas are no more fuel efficient than 87 octane fuel cars, If the 91...
by David Redszus
Mon May 10, 2021 3:39 pm
Forum: Engine Tech
Topic: Flex hone Rotax 787
Replies: 7
Views: 278

Re: Flex hone Rotax 787

If the bore is to the proper size and shape, a ball hone will work fine, using the correct abrasive. If the size and shape are not correct, a rigid stone must be used for shape correction. If the liner is cast iron, a silicon carbide abrasive should be used. If the liner is Nikasil, a boron carbide ...
by David Redszus
Mon May 10, 2021 11:48 am
Forum: Chassis / Suspension / Body
Topic: Drilled-Slotted Rotors & differential bore calipers
Replies: 5
Views: 113

Re: Drilled-Slotted Rotors & differential bore calipers

Slots are used on solid rotors to "wipe" them clean of debris and hot gases. Drilled holes are used on vented rotors to improve the air flow through the rotor vents. Very often, holes are drilled randomly (or incorrectly) which does not produce proper heat distribution and then leads to cracking. Wi...
by David Redszus
Sat May 08, 2021 6:51 pm
Forum: Engine Tech
Topic: Flat tappet cams and zinc
Replies: 10
Views: 377

Re: Flat tappet cams and zinc

Once upon a time, I was asked to investigate what surface finish a flat tappet should have; rough or polished. I tried both. The rough surface tappet wore to a smooth finish. The mirror polished tappet surface became rougher with use. They wound up with nearly the same surface finish. The "slipperyn...
by David Redszus
Sat May 08, 2021 6:41 pm
Forum: Engine Tech
Topic: 95 RON standardized as new high octane?
Replies: 18
Views: 526

Re: 95 RON standardized as new high octane?

If more) Ethanol is the method of increasing the fuel octane your fuel consumption will INCREASE. That means you have to buy more fuel per mile driven. That means more fuel volume has to be produced and delivered... More costs more and burning more creates more exhaust polution volume output of the...
by David Redszus
Sat May 08, 2021 2:21 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 70
Views: 1515

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

But for most hobbyists pushrod engines can still produce more than enough power, due to decades of ongoing development, without the cost and complexity of more modern designs Perhaps it is a bit different in the UK, but here in the states, I find it quite difficult to find technicians who are capab...
by David Redszus
Sat May 08, 2021 1:46 pm
Forum: Engine Tech
Topic: 95 RON standardized as new high octane?
Replies: 18
Views: 526

Re: 95 RON standardized as new high octane?

The article raises several interesting points. The transportation industry is under severe pressure to meet higher fuel economy standards. This would require an increase in compression ratio in order to improve thermal efficiency. Currently, oil companies are limited as to what they can legally prod...
by David Redszus
Thu May 06, 2021 12:24 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: Well they finally did it
Replies: 75
Views: 3439

Re: Well they finally did it

Personally, I think "hybrids" are the way to go for regular transportation vehicles. If gasoline powered engines can be made much smaller, more efficient, and with turbos, more powerful, (which is being done), what is the advantage of a hybrid considering the additional weight to be lugged around? ...
by David Redszus
Wed May 05, 2021 10:32 am
Forum: Engine Tech
Topic: piston weight
Replies: 81
Views: 7244

Re: piston weight

The physical properties of wrist pins has been well known for over 75 years. They can be modeled very accurately. The bending and distortion effects can be calculated on your desktop. That's the easy part. The more difficult part, is to know what forces will affect the wrist pin, what the distortio...
by David Redszus
Tue May 04, 2021 11:42 am
Forum: Engine Tech
Topic: piston weight
Replies: 81
Views: 7244

Re: piston weight

The physical properties of wrist pins has been well known for over 75 years. They can be modeled very accurately. The bending and distortion effects can be calculated on your desktop. That's the easy part. The more difficult part, is to know what forces will affect the wrist pin, what the distortion...
by David Redszus
Mon May 03, 2021 8:34 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 70
Views: 1515

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

We must now add one other American owned constructor, McLaren. As a matter of fact, the rights to F1, is also, now American owned. But, it is sad that there have been so few American drivers. You did forget, at least two American F1 drivers, Eddie Cheever and Alexander Rossi. McLaren is a British c...
by David Redszus
Mon May 03, 2021 8:20 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: Well they finally did it
Replies: 75
Views: 3439

Re: Well they finally did it

One might wonder just where does our electrical energy come from? A quick breakdown of energy sources. Petroleum.........37% Natural gas........32% Coal................11% Nuclear..............9% ...sub total.......89% Renewables......11% Of the renewables Geothermal..........2% Hydro..................
by David Redszus
Mon May 03, 2021 7:40 pm
Forum: Vintage/Classic/Historical Engine Tech
Topic: I Still Like Pushrods, They're Still Viable
Replies: 70
Views: 1515

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

The answer is, Dan Gurney. His car, Eagle His engine, Gurney/Westlake He drove his car, too Although not a American, Jack Brabham was the only other, to do so. But, that is really irrelevant. Penske just didn't knock on enough doors, I guess. Just like his US competitors didn't. American drivers wh...
by David Redszus
Mon May 03, 2021 6:39 pm
Forum: Engine Tech
Topic: piston weight
Replies: 81
Views: 7244

Re: piston weight

like everything its best to use only what is needed as far as wrist pin go. People try to push the limits and get burnt as there is no simple formula to tell you. Personally i think the reciprocating weight is way overrated in the majority of applications as far as importance, more potential pain t...