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Search found 2519 matches

by Tuner
Wed May 12, 2021 1:51 pm
Forum: Engine Tech
Topic: Cooling fan shootout - Engine Masters
Replies: 74
Views: 2175

Re: Cooling fan shootout - Engine Masters

Car Craft, May 2000, p50-51. Fan dyno test.

No fan 496hp
Black Magic fan, running 494hp
plastic fan 460hp
flex fan 466hp
hi-perf flex fan 476hp
6-blade rigid fan 449hp
non-thermal clutch fan 485hp
4-blade rigid fan 473hp
HD thermal clutch fan 476hp
thermal clutch fan 487hp
by Tuner
Tue May 11, 2021 6:04 pm
Forum: Engine Tech
Topic: Cooling fan shootout - Engine Masters
Replies: 74
Views: 2175

Re: Cooling fan shootout - Engine Masters

Tuner- it is plausible that your test showed no power loss to a fan, but basic research methodology required one to consider confounding variables- or factors that could influence the data without being obvious. It is always something that needs to be considered in R&D. Here is a quick video; https...
by Tuner
Mon May 10, 2021 10:23 pm
Forum: Engine Tech
Topic: Cooling fan shootout - Engine Masters
Replies: 74
Views: 2175

Re: Cooling fan shootout - Engine Masters

And I don't believe you have much actual experience with the same engines run on engine dynos and chassis dynos, the same engine run on each, first one and then the other. My example above was a manual transmission car, so no confusion in the chassis dyno smoke and mirror parlor trick about how much...
by Tuner
Mon May 10, 2021 6:28 pm
Forum: Engine Tech
Topic: Cooling fan shootout - Engine Masters
Replies: 74
Views: 2175

Re: Cooling fan shootout - Engine Masters

How many time can I tell you we put a 14" plastic fan on a 355 SBC short track car on a chassis dyno and it didn't change the RWHP at all. The fan belonged to the dyno owner so we removed it when done and made another pull and same result, no change in RWHP at all. Don't ask me why, you make up a re...
by Tuner
Sun May 09, 2021 5:27 pm
Forum: Engine Tech
Topic: pistons GM 3959456
Replies: 5
Views: 271

Re: pistons GM 3959456

Some of you will have read previous threads. I have taken inspected the parts of the original block in my 79 vette. After removing the carbon on the piston tops, I found partnumber 3959456. These are domed pistons. What was the original intention of these pistons? They seem fairly high CR pistons (...
by Tuner
Sun May 09, 2021 5:24 pm
Forum: Engine Tech
Topic: Misfiring, then rod noise?
Replies: 11
Views: 367

Re: Misfiring, then rod noise?

Spun rod bearing, bearing shells overlap and take up the clearance so very little audible knock at low RPM, high RPM centrifugal force moves bearing halves to outside of crank throw so with no bearing in the rod cap the piston bounces off the head.
by Tuner
Sat May 08, 2021 2:33 pm
Forum: Engine Tech
Topic: Cooling fan shootout - Engine Masters
Replies: 74
Views: 2175

Re: Cooling fan shootout - Engine Masters

A V belt powers the mowing deck on my 27hp garden tractor, so yeah. That belt is 1/2 or 5/8 inch wide. How much power goes to propelling the mower vs. turning the blades? Come on people, look at the 5 HP electric motor on your shop air compressor, do you see two 5/8" belts? A 3/8" V belt is not goi...
by Tuner
Sat May 08, 2021 12:12 am
Forum: Engine Tech
Topic: Cams
Replies: 14
Views: 1072

Re: Cams

Comp are at the forefront of lobe design and R@d Their low shock spintron tested designs will help you get what get what you need Marking B.S. What they're marketing as cutting edge, is what we've been doing for decades. "Low Shock" is their term for an inverse radius design. They don't want anyone...
by Tuner
Fri May 07, 2021 11:32 pm
Forum: Engine Tech
Topic: Quick Fuel SS750AN Tuning
Replies: 77
Views: 1642

Re: Quick Fuel SS750AN Tuning

Make a sharpie mark at the height of the uppermost E-hole on the outside of metering block and set the float level to that or very slightly above it ~~1/16" or so.
by Tuner
Fri May 07, 2021 10:14 pm
Forum: Engine Tech
Topic: Flex hone Rotax 787
Replies: 7
Views: 330

Re: Flex hone Rotax 787

If the cylinder walls are smooth and shiny just install new rings, don't do anything to the walls.

What does the Rotax service manual suggest?
by Tuner
Fri May 07, 2021 10:13 pm
Forum: Engine Tech
Topic: Quick Fuel SS750AN Tuning
Replies: 77
Views: 1642

Re: Quick Fuel SS750AN Tuning

I don't remember, or if you said, what size the idle air bleed is. I would try a smaller idle air bleed. You may need to go back up a size on the MJ. Maybe the float level is too low. What is the fuel pressure? Float level and IAB are simple to change without taking anything apart (bowl off) so play...
by Tuner
Fri May 07, 2021 7:59 pm
Forum: Engine Tech
Topic: Cooling fan shootout - Engine Masters
Replies: 74
Views: 2175

Re: Cooling fan shootout - Engine Masters

You really think 30 HP + the water pump through a 3/8" V belt? #-o A V belt powers the mowing deck on my 27hp garden tractor, so yeah. That belt is 1/2 or 5/8 inch wide. How much power goes to propelling the mower vs. turning the blades? Come on people, look at the 5 HP electric motor on your shop ...
by Tuner
Fri May 07, 2021 7:33 pm
Forum: Engine Tech
Topic: Quick Fuel SS750AN Tuning
Replies: 77
Views: 1642

Re: Quick Fuel SS750AN Tuning

You have .031" ? put them in. It probably needs .028" or .026". Are we referring to smaller MAB's all around to fix the WOT condition I described above? This seems counterintuitive to me? Yes, smaller all around. It is getting leaner as the RPM climbs because the bleed is larger than ideal. The yea...
by Tuner
Fri May 07, 2021 3:28 pm
Forum: Engine Tech
Topic: Quick Fuel SS750AN Tuning
Replies: 77
Views: 1642

Re: Quick Fuel SS750AN Tuning

You have .031" ? put them in. It probably needs .028" or .026".
by Tuner
Fri May 07, 2021 2:16 pm
Forum: Engine Tech
Topic: Quick Fuel SS750AN Tuning
Replies: 77
Views: 1642

Re: Quick Fuel SS750AN Tuning

Change the MAB.