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Search found 1039 matches

by PRH
Sun Jun 20, 2021 11:59 am
Forum: Engine Tech
Topic: 2.00” or 2.02” intake valve in a 351w D0OE head?
Replies: 30
Views: 791

Re: 2.00” or 2.02” intake valve in a 351w D0OE head?

I’m thinking that on a SBF for a warmed over pick-up truck or DD/mild hot street car, a set of heads that had 1.9-ish intake valves that flowed in the 190-200 range by .500 lift would be more than sufficient to feed a combo that offered a significant seat-of-the-pants improvement over the stock powe...
by PRH
Thu Jun 17, 2021 6:42 pm
Forum: Engine Tech
Topic: 2.00” or 2.02” intake valve in a 351w D0OE head?
Replies: 30
Views: 791

Re: 2.00” or 2.02” intake valve in a 351w D0OE head?

For what it seems like the OP is usually doing with these milder builds, where he’s wanting distinctly more low end grunt......... I’d suggest warming up to the idea of aftermarket heads(like an E Street) and 4” stroke cranks(SBF). Fairly mild 400” small blocks will get close to that 480-500ft/lb ra...
by PRH
Wed Jun 16, 2021 2:54 pm
Forum: Engine Tech
Topic: 2.00” or 2.02” intake valve in a 351w D0OE head?
Replies: 30
Views: 791

Re: 2.00” or 2.02” intake valve in a 351w D0OE head?

If you’re trying to build something “good”, start with fresh heads and do them up the right way. The “yeh, they’ll work if........” heads go on low buck builds where they just need to run and be somewhat reliable. Using poorly prepared heads is along the same lines as using the “wrong” heads(maybe e...
by PRH
Tue Jun 15, 2021 6:14 pm
Forum: Engine Tech
Topic: Port volume vs flow vs velocity
Replies: 57
Views: 1701

Re: Port volume vs flow vs velocity

double post
by PRH
Tue Jun 15, 2021 6:13 pm
Forum: Engine Tech
Topic: Port volume vs flow vs velocity
Replies: 57
Views: 1701

Re: Port volume vs flow vs velocity

Having not done this particular test, I’m going out on a limb and am going to make the “assumption”, that if a typical 351w combo was put together to make somewhere around 1.0-1.2hp/ci(cam, intake, headers, carb) and I had one set of heads, and successively reworked them to these three levels..........
by PRH
Tue Jun 15, 2021 5:57 pm
Forum: Engine Tech
Topic: Port volume vs flow vs velocity
Replies: 57
Views: 1701

Re: Port volume vs flow vs velocity

It’s seems pretty simple to me......... if bigger and slower was the universal answer....... the head companies would stop selling all those different sized heads. Why didn’t GM put the rect port heads on dump truck engines? The size of the port should match the application and it’s intended use/ope...
by PRH
Tue Jun 15, 2021 11:26 am
Forum: Engine Tech
Topic: Port volume vs flow vs velocity
Replies: 57
Views: 1701

Re: Port volume vs flow vs velocity

On a small port OEM head, if you concentrate on blending and smoothing but try to limit actually increasing the port size, you can see some pretty sizable gains on the flow bench with very minimal increases in port size…but it comes at a cost of much higher port velocity. Within the realm of “milde...
by PRH
Sun Jun 13, 2021 12:02 pm
Forum: Engine Tech
Topic: Looking for opinions on this Crower cam for a Pontiac stroker 400
Replies: 20
Views: 608

Re: Looking for opinions on this Crower cam for a Pontiac stroker 400

There have been a couple of 455/467 builds on the dyno here fairly recently. Both used bowl ported 64 heads, RPM intakes, 4 tube headers, 1.5 rockers. One had a Q-jet and a hyd cam from Butler that was like 230/236-110. The other had a Proform 850 and a solid cam that was 242/246-112. Both made peak...
by PRH
Thu Jun 10, 2021 10:26 am
Forum: Engine Tech
Topic: How to select the right carb boosters?
Replies: 32
Views: 1985

Re: How to select the right carb boosters?

365” SBM, 9.7cr, .500” lift solid cam, dual plane manifold with no spacer, 1-3/4” headers. Pump gas with a Holley 4779 on this pull. Solidly over 400hp....... under 600cfm air consumption. A Ede 750 made within a couple of hp. The only way a carb with a flow capacity that is actually only 100cfm low...
by PRH
Wed Jun 09, 2021 6:10 pm
Forum: Engine Tech
Topic: 243 LS SSR...Stumped.
Replies: 32
Views: 1754

Re: 243 LS SSR...Stumped.

Still sounds to me like what TK was suggesting and what DT was instructing are fundamentally the same thing.
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by PRH
Wed Jun 09, 2021 5:45 pm
Forum: Engine Tech
Topic: How to select the right carb boosters?
Replies: 32
Views: 1985

Re: How to select the right carb boosters?

I would have thought that on a street engine you'd want all the vaporization and low speed manners you could get and damn the 15hp (or whatever) it costs. In this situation it’s more than a 15hp difference…it feels more like 50. Seriously. In my mind, for there to be anywhere near that kind of powe...
by PRH
Tue Jun 08, 2021 6:01 pm
Forum: Engine Tech
Topic: 243 LS SSR...Stumped.
Replies: 32
Views: 1754

Re: 243 LS SSR...Stumped.

Finish the turn with 80 grit linishing tape pulled back & forth over it. What Tony is describing is NOT the riblet, It's basically smoothing the apex in the direction of flow. Speeds are fast and boundary layer thin and fuel is trying to turn. It's not a cfm gain,more helping with stability. It's a...
by PRH
Sat Jun 05, 2021 6:52 pm
Forum: Engine Tech
Topic: 193 Swirl Port Porting Question
Replies: 24
Views: 1012

Re: 193 Swirl Port Porting Question

I don't think it is worth the time and effort opening throat,I doubt you would notice any difference, if you are using those heads as is I would just lap the valves and pat it on the head. The minimum I would do personally is a valve job,set throat and bowl size,shape guide,blend top cut of valve j...
by PRH
Sat May 22, 2021 5:14 pm
Forum: Engine Tech
Topic: Whiplash, Thumper, Bootlegger etc cams
Replies: 27
Views: 1848

Re: Whiplash, Thumper, Bootlegger etc cams

We had a very bread n butter 350 with the middle Thumpr cam(235/247-107) in it on the dyno not long ago. Ootb E-Streets, flat tops, right about 10:1, 1-5/8” headers, 1.5 rockers, A/G intake. It made surprisingly good power, and hung on quite well. I personally don’t care for the idle characteristics...
by PRH
Fri May 21, 2021 11:04 am
Forum: Engine Tech
Topic: What Happens When..............
Replies: 37
Views: 3571

Re: What Happens When..............

1. Do ported heads help when the cam is the cork? 2. Where will peak HP be made? 3. Is the factory 390 HP 427 HP rating correct? 4. I'am I wasting my time? 5. How good is the factory cast iron intake? I took Mikes comment about the takeaways from dyno testing at 23.5” baro vs 30” baro as meaning......