Speed-Talk is running on www.Speed-Talk.com

IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/
(Right-click the URL and select "Bookmark this link")

Search found 882 matches

by Tom68
Thu Feb 02, 2023 2:41 am
Forum: Engine Tech
Topic: 5.7 Vortech gaskets
Replies: 2
Views: 77

5.7 Vortech gaskets

Mostly after sump gasket recommendations, but full sets to.

Bloody expensive in OZ, so don't wat to pay a lot of money and still end up with crap.
by Tom68
Thu Feb 02, 2023 12:14 am
Forum: Engine Tech
Topic: 347 Street Cam
Replies: 37
Views: 742

Re: 347 Street Cam

We are straying a bit far here. I dont want to turn it into a grocery getter, just tone it down some. Ford racing sell their 363s with super victor manifolds, with a 232/240 112 LSA HR. Thats half the overlap of the 236/248 109 LSA cam I am currently using. I'd like to do something similar, but wit...
by Tom68
Thu Feb 02, 2023 12:01 am
Forum: Engine Tech
Topic: Alternative fuel enrichment
Replies: 29
Views: 909

Re: Alternative fuel enrichment

Is there not a difference between heat created and efficient heat transfer to lower the heat post combustion? So I can see both sides. With conservation of energy the greatest torque is made due to greatest combustion energy that would become heat as we know. Faster more efficient burn has more exp...
by Tom68
Wed Feb 01, 2023 7:22 pm
Forum: Engine Tech
Topic: Alternative fuel enrichment
Replies: 29
Views: 909

Re: Alternative fuel enrichment

Another interesting thing that people believe that engines run hotter when you lean them out. They make the most heat in the combustion chamber at the AFR where they give max hp and run cooler above and below that. Erland They do run hotter when lean. Combustion temp is lower but longer. The energy...
by Tom68
Wed Feb 01, 2023 1:08 am
Forum: Engine Tech
Topic: vacuum advance goes to manifold vac?
Replies: 30
Views: 2239

Re: vacuum advance goes to manifold vac?

jake197000 wrote: Tue Jan 31, 2023 1:43 pm doesnt matter ecept for too high of idle when hooked to manifold.
Takes a tight carby to get the idle down when you've got a good ignition curve, really hard with twin carbs.
by Tom68
Wed Feb 01, 2023 1:05 am
Forum: Engine Tech
Topic: Ported vs manifold vacuum for ignition advance?
Replies: 30
Views: 2967

Re: Ported vs manifold vacuum for ignition advance?

Well if you can pull the vacuum hose from your carb and nothing happens, you probably have ported vacuum. But most of the time your manual says pull the hose and plug the carb for initial timing. If it would be true PVA, that would make absolute no sense. Many of the stock vacuum ports that the fac...
by Tom68
Wed Feb 01, 2023 1:02 am
Forum: Engine Tech
Topic: Ported vs manifold vacuum for ignition advance?
Replies: 30
Views: 2967

Re: Ported vs manifold vacuum for ignition advance?

Not sure how that proves that PVA was used for emissions reasons? PVA was used in the 40s and 50s when performance and efficiency were a concern and emissions weren't given a second thought. This is well documented in automotive engineering texts and service manuals. I guess we'll have to agree to ...
by Tom68
Wed Feb 01, 2023 12:33 am
Forum: Engine Tech
Topic: 347 Street Cam
Replies: 37
Views: 742

Re: 347 Street Cam

Honestly I'd rather swap cams than modify a dual plane manifold for EFI - you are looking at a decent amount of work, fabrication effort and cost to do so. The runners aren't the same height/ angle etc. Plus some porting to make it somewhat match the heads. Even then the short runners to a common p...
by Tom68
Tue Jan 31, 2023 5:05 pm
Forum: Engine Tech
Topic: Decent cylinder liner puller
Replies: 3
Views: 123

Re: Decent cylinder liner puller

I recently bought a hollow ram. Would work with that kit.
Excellent for pushing harmonic balancers on And pulling suspension bushes.
by Tom68
Tue Jan 31, 2023 4:56 pm
Forum: Engine Tech
Topic: 347 Street Cam
Replies: 37
Views: 742

Re: 347 Street Cam

Not my Holden.

The dual plane 1500 to 5500 power range is not runner length as much as it is shared reversion pulses. The closing of one intake bounces back to the next opening valve as it can't easily reverse through the already flowing carby. With an IR that reversion pulse become stand off.
by Tom68
Tue Jan 31, 2023 2:24 pm
Forum: Engine Tech
Topic: 347 Street Cam
Replies: 37
Views: 742

Re: 347 Street Cam

I did see that. Its port EFI though. The 180 degree separation still helps even with the port EFI. Not as much improvement as with a carb. My question would be do you want more power at say 1500 ? or dose it just need to be more drivable ? 180 degree separation will reduce (not eliminate) exhaust d...
by Tom68
Tue Jan 31, 2023 1:13 am
Forum: Engine Tech
Topic: Post up your VE %
Replies: 9
Views: 463

Post up your VE %

Facts based databank.

Engine combo, VE % and how it was determined, Engine Dyno ? Chassis Dyno? Sim ?
by Tom68
Tue Jan 31, 2023 12:48 am
Forum: Engine Tech
Topic: Low speed (1500-1800 RPM) driveability issue
Replies: 145
Views: 8220

Re: Low speed (1500-1800 RPM) driveability issue

Is you hyd roller cam (107° LSA) a Thumpr Cam? These cams need a ton of base initial spark timing at idle. 18 base + vacuum advance at idle is NOT ENOUGH. You need to recurve the diz mechanical adv curve for a SHORT limited 10° advance curve. This will allow 26-28 ° Base initial timing and 36-38 to...
by Tom68
Tue Jan 31, 2023 12:42 am
Forum: Engine Tech
Topic: 347 Street Cam
Replies: 37
Views: 742

Re: 347 Street Cam

I did see that. Its port EFI though. The 180 degree separation still helps even with the port EFI. Not as much improvement as with a carb. My question would be do you want more power at say 1500 ? or dose it just need to be more drivable ? 180 degree separation will reduce (not eliminate) exhaust d...
by Tom68
Mon Jan 30, 2023 11:29 pm
Forum: Engine Tech
Topic: 347 Street Cam
Replies: 37
Views: 742

Re: 347 Street Cam

Did you see how GRT got happy with his too much overlap cam for the street ? Fully divided dual plane. He does have a couple of extra cubes for some low speed power though. https://www.speed-talk.com/forum/viewtopic.php?f=1&t=58475 You will of course drop some power at 7000, but it'll still go there.