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Search found 28 matches

by E.Roy
Tue Jan 14, 2020 7:28 pm
Forum: Engine Tech
Topic: What is cylinder head choke
Replies: 18
Views: 1051

Re: What is cylinder head choke

With a 23 degree SBC head in terms of aftermarket ones you need to to be in port volume range of 195 to 215 CCs and air flow numbers of greater then 270 cfm@28" before the port area at the push rod buldge becomes a choke point, and even then the flow loss seen is more due to the air stream being fo...
by E.Roy
Sun Apr 08, 2018 8:35 am
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

The post was just to spur some thought and discussion. :D Keep in mind, that flow path works both ways. If you make it easy for the intake to flow to the ex, the ex can just as easily flow to the intake. Things aren't a nice steady flow in one direction in a engine. I've seen some engines with ex s...
by E.Roy
Sat Apr 07, 2018 12:09 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

Randy, I'm trying to make it easier for the exhaust pulse suction to get the intake port up to velocity How do you go about achieving that ? How do you know your ex system has a "ex pulse suction" ? How do you know you have done what it takes to "get the intake port up to velocity" ? Is it always a...
by E.Roy
Wed Apr 04, 2018 1:47 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

Moderate compression up to 10.5:1 is part of the plan. My budget limited plan is using the stock pistons, so I will need to have heads milled near .030 and use a beaded steel .015 gasket (12cc dish .025 in the hole) I agree on headers, maybe find a tri-y like the Doug Thorley used by the Creason tea...
by E.Roy
Tue Apr 03, 2018 4:53 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

Had to dig them up, I keep almost everything but finding it is the harder part. It was... 8mm LS valves 2"/1.55" flowing 248/219 @.500".. with no exhaust pipe on 4" bore. Kept flowing up to .700" where we stopped the testing. Swirl was 1310rpm which was actually better than I had remembered. Keep i...
by E.Roy
Tue Apr 03, 2018 12:35 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

Thanks for the input, sounds like I'm on the right course then. I edited my post on you to add this "On the intake I'm focusing on 3 areas, blending the seat to bowl, narrowing the guide boss to a vane, and taking .100" out at the pushrod pinch because I think stock it gets flow separation." I coul...
by E.Roy
Tue Apr 03, 2018 12:13 am
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

Sounds interesting, and I wish you luck,... but I think your being optomistic on your tq numbers. 450 is a little optomistic for that combo, but I don't know your porting skills, so ? Randy I really like porting and I feel like I'm being scientific on these vortecs, I made an intake port mold which...
by E.Roy
Mon Apr 02, 2018 11:37 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

I'm trying to yes. This is the event: http://www.grmchallenge.com Your allowed to sell off parts of the car or parts deals and recoup up to 1/2 the budget, $1009 this year, so you can spend $2018 +$1009 if you can sell $1009 in parts. They allow 1 set of tires that don't hit the budget. I bought an...
by E.Roy
Mon Apr 02, 2018 1:02 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

I'm building to a magazine competition budget, an entire vehicle for $2018 outlay, to run 1/4, autocross and appearance score. So I've selected the vortec 350 as my engine because of its oem roller cam block, I got a 98 bolt for for $200, and comes with roller bits I can reuse. Your building a 500 ...
by E.Roy
Sun Apr 01, 2018 9:38 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

If you want 500 lb ft and 400 hp, toss the 350 and build a 400. I don't personally have the time to fight with an engine to make it do something it is incapable of achieving. Good idea, 400ci for 550 lbft haha Why not? I just came across a 400 built on a $2500 budget with 225cc intake port, modifie...
by E.Roy
Sun Apr 01, 2018 7:20 am
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

Excerpt from this online tech tip, from the book CHEVY BIG-BLOCKS: HOW TO BUILD MAX PERFORMANCE ON A BUDGET. by David Vizard (geared towards BBC but he applies to many engines) https://www.chevydiy.com/chevy-big-block-performance-camshaft-and-valvetrain-events/ "The Importance of Overlap The events ...
by E.Roy
Fri Mar 30, 2018 8:06 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

Those numbers sound more realistic. Still a nice little streeter. Lots of things get said along the way in all these posts .. Another... Advancing cam timing on a Chevy v-8 would be the same on just about every one ever made because there is not much difference in piston speed and compression from ...
by E.Roy
Fri Mar 30, 2018 7:46 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

That cam was optimal for that combos desired use and at that compression. Who says, and how would you know if you didn't try a different one ? Without trying anything else you wouldn't. Randy That's true, but read through hundreds of similar combos with their dyno results. This was as good as most ...
by E.Roy
Fri Mar 30, 2018 1:32 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

It would have been interesting if they had followed up the first test with a higher ratio intake rocker, tested intake center-line for best position and then tried a small single plane. Or adjusted the intake centerline to the 500ftlb level? :D Just messing with you E.roy! I'm suppose to be the sar...
by E.Roy
Fri Mar 30, 2018 1:05 pm
Forum: Engine Tech
Topic: Advantages of advancing the cam on a street engine?
Replies: 102
Views: 44723

Re: Advantages of advancing the cam on a street engine?

It would have been interesting if they had followed up the first test with a higher ratio intake rocker, tested intake center-line for best position and then tried a small single plane. Or adjusted the intake centerline to the 500ftlb level? :D Just messing with you E.roy! LOL, zing! It's gotta be ...