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Search found 84 matches

by BLSTIC
Tue Oct 27, 2020 6:09 pm
Forum: Engine Tech
Topic: Ignition advance at cruise rpm?
Replies: 42
Views: 1273

Re: Ignition advance at cruise rpm?

I was going to suggest pulling the spark maps from various EJ25 engines that people have modified and posted online. There's a wide range of similar engines running different compression ratios because turbo, because vct, etc.
by BLSTIC
Fri Oct 16, 2020 8:42 pm
Forum: Engine Tech
Topic: Ignition timing after porting
Replies: 13
Views: 827

Re: Ignition timing after porting

It also sounds like you made the exhaust port larger when you already likely had a port and header that was too large in that area. Port energy/velocity fights reversion even in the absence of steps/chambers/what-have-you. If you think that port matching you did hurt things you may be able to make s...
by BLSTIC
Fri Oct 02, 2020 10:58 am
Forum: Engine Tech
Topic: Turbo Baby Steps:Inducer and Exducer
Replies: 6
Views: 493

Re: Turbo Baby Steps:Inducer and Exducer

Don't forget, twin scroll also separates exhaust pulses from other cylinders, reducing, or in some cases eliminating, blowdown interference. It's like going from a single outlet manifold to a set of super long 4-2-1 (or 6-2-1 if that's your thing), except it only takes up marginally more room.
by BLSTIC
Tue Sep 29, 2020 12:52 pm
Forum: Engine Tech
Topic: Worn rings, end gap and blowby
Replies: 32
Views: 1208

Re: Worn rings, end gap and blowby

I've always thought it was mainly about reduced ring tension as the ring and bore wear. Not that the gap makes blow by itself, but it represents a ring that has now worn to spread out more (like if a valve spring seat was a wear surface the spring would get marginally shorter free length and margina...
by BLSTIC
Sun Sep 27, 2020 9:29 am
Forum: Engine Tech
Topic: Dyno result for the risky business Porsche
Replies: 174
Views: 27737

Re: Dyno result for the risky business Porsche

GTX3576... I like those turbos. There's even a twin scroll internal gate housing available for them if you like truck parts.
by BLSTIC
Thu Sep 24, 2020 10:09 am
Forum: Engine Tech
Topic: Time to gap the valves
Replies: 8
Views: 923

Re: Time to gap the valves

Wasn't 2004 roughly when they were discovering that small ports increased overall performance and before charge motion was seen as so important? What I guess I'm trying to say is, your head is good but there's more on the table. What's the latest model head that fits your block and frame? Can you ap...
by BLSTIC
Thu Sep 24, 2020 5:49 am
Forum: Engine Tech
Topic: 202ci intake manifold ideas
Replies: 32
Views: 695

Re: 202ci intake manifold ideas

What's your goal power wise without nitrous? That will determine your intake csa more than anything. A well developed 202ci engine at 7000rpm is going to be making north of 300hp by itself, making that amongst the most powerful Holden 6's ever built
by BLSTIC
Thu Sep 24, 2020 12:22 am
Forum: Engine Tech
Topic: 202ci intake manifold ideas
Replies: 32
Views: 695

Re: 202ci intake manifold ideas

I've seen a v8 Trimatic run 10.8 behind a 383 in a not stripped VC, so those can handle the punishment if built. There's also the Duggan or Jzed head for that motor. Much more downdraft port. What car are you running it in? PS if there's no rules it would be killer to see a turbo efi Holden six do a...
by BLSTIC
Wed Sep 23, 2020 10:15 pm
Forum: Engine Tech
Topic: 202ci intake manifold ideas
Replies: 32
Views: 695

Re: 202ci intake manifold ideas

There's a reason Holden went to RB engines :p

But really I'd go 2x4 in a spreadbore format, even if it is just a drag car you'll appreciate the tiny primaries being able to move the car at less than full throttle. Sounds like you won't need much airflow though.

Does your class ban efi?
by BLSTIC
Mon Sep 21, 2020 10:04 am
Forum: Engine Tech
Topic: Quiet external EFI fuel pump experience
Replies: 43
Views: 1312

Re: Quiet external EFI fuel pump experience

Have you tried rubber mounting it on a proper isolating mount (ie one where you can move the pump slightly with little force) and using a fuel pressure damper close to the pump? Fuel pressure dampers are easily available at a wrecker yard. You'll still hear it, but with any luck you won't hear the w...
by BLSTIC
Sat Sep 19, 2020 11:18 am
Forum: Engine Tech
Topic: Carb'd Procharger vs Supercharger...
Replies: 8
Views: 671

Re: Carb'd Procharger vs Supercharger...

Are the procharged guys intercooled? You're looking at a double whammy of temperature effects if they are. A roots blown motor will suck in air at whatever density is on the day and as long as timing and fuel remain right your power isn't going to vary that much. A centrifugal pump is not a fixed vo...
by BLSTIC
Wed Sep 09, 2020 9:13 pm
Forum: Engine Tech
Topic: Header Tube and Collector Specs "Trends"
Replies: 41
Views: 2415

Re: Header Tube and Collector Specs "Trends"

From what I have seen on dyno testing with carbs and tri-Y headers I get a flat spot around 3500 RPM. Around this RPM the lambda reads rich from double carburating. From my understanding this is because of the second reflection from the first junction in the tri-Y header. A positive pressure wave g...
by BLSTIC
Sat Aug 29, 2020 8:43 pm
Forum: Engine Tech
Topic: Engine Software
Replies: 13
Views: 699

Re: Engine Software

I've got engine analyzer plus (EA+). Totally worth the upgrade over base (note, I've got plus, not pro). Easy to use, fast, cheap, pretty close to reality. Lacking in manifold design and especially exhaust. No advanced outputs like you'd get with pro or EngMod4t. Pro is apparently also lacking in ex...
by BLSTIC
Sat Aug 29, 2020 7:35 pm
Forum: Engine Tech
Topic: Modern Engines & Static CR vs. Boost Levels?
Replies: 34
Views: 1913

Re: Modern Engines & Static CR vs. Boost Levels?

Where this modern high tumble port excels in my opinion is with long stroke turbocharged four valve engines. Long stroke compared to bore allows for a high combustion chamber without a piston dome, as does turbocharging and the associated lower compression ratio. Also check this screenshot out. It'...
by BLSTIC
Mon Apr 27, 2020 12:16 am
Forum: Engine Tech
Topic: Checking a long block without disassembly?
Replies: 6
Views: 480

Re: Checking a long block without disassembly?

It's what I expected to hear as I can't see a viable way of doing it.

Not what I wanted to hear though :(