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Search found 8959 matches

by F-BIRD'88
Wed Sep 28, 2022 7:27 am
Forum: Engine Tech
Topic: 034 Chevy Bowtie Semi Finished Heads
Replies: 10
Views: 349

Re: 034 Chevy Bowtie Semi Finished Heads

Are the Bowtie Vortec heads internet rumoured to be "prone to cracking". or you have used a set or 2 that have cracked on you? The GMPP Bowtie Vortec head is a much heavier beefy er casting than the OEM L-31 truck engine 062/906 castings were. The OEM 062/906 heads got the reputation of cracking bec...
by F-BIRD'88
Mon Sep 26, 2022 11:57 am
Forum: Engine Tech
Topic: What was Chevrolet thinking ?
Replies: 27
Views: 1068

Re: What was Chevrolet thinking ?

Skinny. in all due respect you are just not going to learn what needs to be learned by computer sim ing this stuff to death....
You need to get in there and get dirty. Cam in motor , in car... Car down ¼ mile... Time slip yeee ha or wow What happened :( ha ha
by F-BIRD'88
Mon Sep 26, 2022 11:42 am
Forum: Engine Tech
Topic: What was Chevrolet thinking ?
Replies: 27
Views: 1068

Re: What was Chevrolet thinking ?

Without having this 235/235 cam on hand I estimate the seat to seat duration to be about 290 to 305 using the Comp cams standard. .006" @ the lobe. This cam and ever other 235° ish hyd roller cam On 114 LSA ,straight up.. Has a rough idle. In the car it does not like a stock low stall torque convert...
by F-BIRD'88
Mon Sep 26, 2022 10:47 am
Forum: Engine Tech
Topic: What was Chevrolet thinking ?
Replies: 27
Views: 1068

Re: What was Chevrolet thinking ?

You would want to get one and actually measure the seat to seat durations @ what ever check height gives you a warm fuzzy feeling. .004". .006". .006"+ lash @the valve. or. ???. When doing that in the engine you have to be real carfull to get accurate measurment.. Either read off the top edge of the...
by F-BIRD'88
Mon Sep 26, 2022 10:18 am
Forum: Engine Tech
Topic: What was Chevrolet thinking ?
Replies: 27
Views: 1068

Re: What was Chevrolet thinking ?

Those do not represent the .050" timing of the 071 cam in the engine. It is I believe 3 to 4 degrees advanced. 112 LSA. 108/116 or 109/115 centers The other old ZZZ cam 235/235° was in "straight up" 114/114.. Part of the reason end users found that the engines with this cam lacked low/ mid range tor...
by F-BIRD'88
Sun Sep 25, 2022 1:45 pm
Forum: Engine Tech
Topic: How much advance for a less than optimal cam ?
Replies: 22
Views: 644

Re: How much advance for a less than optimal cam ?

The cams of same .,,050" spec and same events open close @ .050" on all the various high perf hyd flat tappet sbc cams will run MORE ALIKE THAN DIFFERENT. the real different in relative seat to seat real durations will be vey small +/-.. The practical design mechanical limitations are the same.. un...
by F-BIRD'88
Sun Sep 25, 2022 1:34 pm
Forum: Engine Tech
Topic: How much advance for a less than optimal cam ?
Replies: 22
Views: 644

Re: How much advance for a less than optimal cam ?

Assuming that the events below .050” is the same is a big assumption. The engine sees seat-to-seat duration, not .050”. You can’t compare a Mike Jones designed lobes to Billy Godbold has designed lobes to Harold Brookshire designed lobes look at .050. Mike’s cams look smaller at .050” than they run...
by F-BIRD'88
Sun Sep 25, 2022 12:55 pm
Forum: Engine Tech
Topic: How much advance for a less than optimal cam ?
Replies: 22
Views: 644

Re: How much advance for a less than optimal cam ?

Assuming that the events below .050” is the same is a big assumption. The engine sees seat-to-seat duration, not .050”. You can’t compare a Mike Jones designed lobes to Billy Godbold has designed lobes to Harold Brookshire designed lobes look at .050. Mike’s cams look smaller at .050” than they run...
by F-BIRD'88
Sun Sep 25, 2022 12:48 pm
Forum: Engine Tech
Topic: How much advance for a less than optimal cam ?
Replies: 22
Views: 644

Re: How much advance for a less than optimal cam ?

Really! And here I am thinking I can degree a cam in at lets say 107.5 ICL without having a cam card. :shock: Stan You don't need a cam card.. You can determine the phasing of the camshaft by measuring that in the engine and the .050" open close events are the best most accurate way to do that then...
by F-BIRD'88
Sun Sep 25, 2022 12:07 pm
Forum: Engine Tech
Topic: How much advance for a less than optimal cam ?
Replies: 22
Views: 644

Re: How much advance for a less than optimal cam ?

Given what information we have I agree. It seems people only like to look at 0.050" numbers anymore and don't care about adv. duration and events. Stan Thats because the .050" specs are a accurate way to reference the relative position of the camshaft in the engine and then to move it +/- as desire...
by F-BIRD'88
Sun Sep 25, 2022 11:15 am
Forum: Engine Tech
Topic: How much advance for a less than optimal cam ?
Replies: 22
Views: 644

Re: How much advance for a less than optimal cam ?

I think a great start would be to note your average cranking compression you have across 8 cylinders now and then get as close to that by messin with the new cam. I must say that if I did not have the bigger cam already and my valve springs could take it, I would just run higher ratio rockers which...
by F-BIRD'88
Sun Sep 25, 2022 10:19 am
Forum: Engine Tech
Topic: How much advance for a less than optimal cam ?
Replies: 22
Views: 644

Re: How much advance for a less than optimal cam ?

"open headers". Incombination with tweeking the installed position of the camshaft you can really boost up the low/mid range torque output with collector extentions and or choke type/merge type header reducer/extentions added to your open headers. This effectivly makes the engine think the headers a...
by F-BIRD'88
Sun Sep 25, 2022 6:46 am
Forum: Engine Tech
Topic: How much advance for a less than optimal cam ?
Replies: 22
Views: 644

Re: How much advance for a less than optimal cam ?

You'd want to move the 230/230 cam ahead by 2 more degrees. Now it has the same intake closing point and the same exhaust opening point as the 226/234 cam. The butt dyno can be decieving. This may not be the best possible position for best perf overall of either cam in the vehicle but its not bad. F...
by F-BIRD'88
Thu Sep 22, 2022 12:07 pm
Forum: Engine Tech
Topic: 128 my take, anybody see it like this ?
Replies: 158
Views: 3986

Re: 128 my take, anybody see it like this ?

355" SBC 10:1 with ported 492 heads, Performer RPM, and Holley 600. RPM---TQ--BHP 3200--436--266 3400--443--287 3600--445--305 3800--444--321 4000--443--337 4200--440--352 4400--440--368 4600--441--386 4800--441--403 5000--432--411 5200--422--418 5400--412--423 5600--400--426 The cam is 216/220, on...
by F-BIRD'88
Thu Sep 22, 2022 11:59 am
Forum: Engine Tech
Topic: 128 my take, anybody see it like this ?
Replies: 158
Views: 3986

Re: 128 my take, anybody see it like this ?

Its almost like the right engine build, with a good induction package will dictate power curve characteristics more so than what lsa you have. LSA is something you end up with. It's not a parameter you design for. If you learned about engines, working on double overhead cam engines, you wouldn't ev...