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Search found 1042 matches

by BradH
Fri Jun 18, 2021 6:33 am
Forum: Engine Tech
Topic: Break in oil magic
Replies: 39
Views: 1863

Re: Break in oil magic

Hey "other guy", ya' got that BR30 VOA handy? :lol:
by BradH
Thu Jun 17, 2021 4:36 pm
Forum: Engine Tech
Topic: Break in oil magic
Replies: 39
Views: 1863

Re: Break in oil magic

Would the last 2 posters be more specific about which brand(s) of break-in oil they are referring to? I've come across VOAs for a few different break-in oils and the variations between them are significant with respect to amounts of zinc & phosphorus additives. I can post a VOA of Driven B30 later ...
by BradH
Thu Jun 17, 2021 4:20 pm
Forum: Engine Tech
Topic: Break in oil magic
Replies: 39
Views: 1863

Re: Break in oil magic

Lake Speed Jr was the certified lube specialist for "Joe Gibbs" Driven Racing Oil. I think, at one time he was at least part owner. He definitely knows his stuff :) He was a salesman for Gibbs. Maybe Joe certified him :lol: When I asked him technical questions about the oil he was trying to sell me...
by BradH
Sat Jun 12, 2021 9:09 am
Forum: Engine Tech
Topic: Break in oil magic
Replies: 39
Views: 1863

Re: Break in oil magic

Would the last 2 posters be more specific about which brand(s) of break-in oil they are referring to? I've come across VOAs for a few different break-in oils and the variations between them are significant with respect to amounts of zinc & phosphorus additives.
by BradH
Wed Jun 09, 2021 9:33 pm
Forum: Engine Tech
Topic: 243 LS SSR...Stumped.
Replies: 32
Views: 1761

Re: 243 LS SSR...Stumped.

FWIW, here's a short turn on my "crash test dummy" head that I just used 50 grit on. Ya' probably need to click on the image to display it more clearly.
20210609_211753.jpg
by BradH
Wed Jun 09, 2021 12:22 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'd like to add some "visual context" to venturi size vs booster config. 1.375" v pri / 1.438" v sec w/ standard Holley straight-leg boosters Holley 3310-4_2.jpeg . 1.425" v w/ a "traditional" down-leg booster BG Gold Claw v2_3.jpeg . 1.50" v w/ a Braswell down-leg which has are larger OD than the "...
by BradH
Wed Jun 09, 2021 9:44 am
Forum: Engine Tech
Topic: 243 LS SSR...Stumped.
Replies: 32
Views: 1761

Re: 243 LS SSR...Stumped.

Don T said to use 36 or 40 grit on the SSR in the direction of flow in order to leave small grooves in the surface, not polish it smooth & shiny. Google "riblet fluid flow" and you'll see multiple links to research papers on the subject going back decades. Ignore the links where the topic is "pork ...
by BradH
Tue Jun 08, 2021 11:11 pm
Forum: Engine Tech
Topic: How to select the right carb boosters?
Replies: 32
Views: 1985

Re: How to select the right carb boosters?

Can you borrow something like a 3310 Holley 750 vac secondary to try out? Depending upon the model and vintage, it would either have straight-leg or downleg boosters. It could give you a good feel for whether you need annulars for your combination using a carb of that size. On smaller venturi, an an...
by BradH
Tue Jun 08, 2021 10:59 pm
Forum: Engine Tech
Topic: 243 LS SSR...Stumped.
Replies: 32
Views: 1761

Re: 243 LS SSR...Stumped.

Don T said to use 36 or 40 grit on the SSR in the direction of flow in order to leave small grooves in the surface, not polish it smooth & shiny. Google "riblet fluid flow" and you'll see multiple links to research papers on the subject going back decades. Ignore the links where the topic is "pork o...
by BradH
Sun Jun 06, 2021 10:37 am
Forum: Engine Tech
Topic: How to select the right carb boosters?
Replies: 32
Views: 1985

Re: How to select the right carb boosters?

Does anyone have info on the NASCAR 4150 830 cfm carb that was supporting 870+ HP? If I have my facts straight, they were basically "control carbs" in that they were limited to 1.59" venturi and 1-11/16" throttle plates. Not exactly an ideal venturi-to-throttle ratio, but everybody had to work w/ t...
by BradH
Fri Jun 04, 2021 11:33 am
Forum: Engine Tech
Topic: How to select the right carb boosters?
Replies: 32
Views: 1985

Re: How to select the right carb boosters?

... There hasn't been a 'Goldilocks' carb built for engines making 600-800 hp. It's beyond the 'sweet spot' of the 4150 style, and the Dominator was never designed to be all that friendly except for racing at wide open throttle. ... Might be the right niche for one of Mike Laws' Twin Blade sizes, i...
by BradH
Tue Jun 01, 2021 3:23 pm
Forum: Engine Tech
Topic: Assumption: Valve train deflection increases with lift & higher spring load
Replies: 9
Views: 642

Assumption: Valve train deflection increases with lift & higher spring load

If you have a valve train that shows 1.55 ratio w/ soft checking spring and 1.50 with actual springs, is it a valid assumption that the valve train deflection increases with lift & higher spring load? Example: You measure a .05 ratio loss based upon differences in max measured lift due to deflection...
by BradH
Sun May 30, 2021 11:15 am
Forum: Engine Tech
Topic: COMP Cams LST solid roller lobes... "Top Secret"?
Replies: 19
Views: 1284

Re: COMP Cams LST solid roller lobes... "Top Secret"?

Billy Godbold has not been secret about these LST designs at all. Pretty easy to find information on them and what he's doing/did. The background info and tech (hype?) explaining the new lobes, yes. The actual lobe specs for the latest lobe profile series they're promoting, no. That's the part wher...
by BradH
Sun May 30, 2021 11:00 am
Forum: Engine Tech
Topic: Building an 11 second 70's nostalgic SBC
Replies: 213
Views: 7516

Re: Building an 11 second 70's nostalgic SBC

Just now looked at the Trick Flow 175cc double-hump heads... IMO, they're your best choice hands down. Don't even bother messing w/ decades-old OEM iron stuff when something like this is an option.
by BradH
Sat May 29, 2021 7:02 am
Forum: Engine Tech
Topic: COMP Cams LST solid roller lobes... "Top Secret"?
Replies: 19
Views: 1284

Re: COMP Cams LST solid roller lobes... "Top Secret"?

Well, this thread has taken an unexpected turn. In no particular order... My request for lobe specs from COMP was "for informational purposes only." Their response struck me as absurd, given they're actively promoting their LST lobes and have even published the names of at least a dozen of the lobe ...