Search found 2935 matches

by randy331
Mon Feb 24, 2020 12:44 am
Forum: Engine Tech
Topic: RPM Air Gap Runner Length (SBC)
Replies: 37
Views: 4161

Re: RPM Air Gap Runner Length (SBC)

Sorry, the "refining an engine spec. Cam selection primarily" part of your post lead me to believe you'd change cam based on runner length.
I just wanted to know how you would change one of them vs the other ??

Randy
by randy331
Sun Feb 23, 2020 11:06 pm
Forum: Engine Tech
Topic: RPM Air Gap Runner Length (SBC)
Replies: 37
Views: 4161

Re: RPM Air Gap Runner Length (SBC)

skinny z wrote: Sun Feb 23, 2020 5:48 pm Refining an engine spec. Cam selection primarily.
So,.. how will different runner lengths change your cam selection?

Say 5" vs 6" vs 7" runner length ?
How will you cam those differently ?
And, why will you cam them differently for those runner length differences ?

Randy
by randy331
Fri Feb 21, 2020 10:55 pm
Forum: Engine Tech
Topic: GMP LS-9 CnC Ported Heads
Replies: 5
Views: 1486

Re: GMP LS-9 CnC Ported Heads

ProPower engines wrote: Fri Feb 21, 2020 4:10 pm Looking for some basic flow numbers to get on with cam choice.
So,... your looking for a "basic cam choice" ??
I mean without exact flow numbers how could you get an exact cam choice??
ProPower engines wrote: Fri Feb 21, 2020 4:10 pm Any info will be greatly appreciated
Stop picking camz with flowZZ!

Randy
by randy331
Tue Feb 18, 2020 11:58 pm
Forum: Engine Tech
Topic: Minimum Cross Sectional Area: Question
Replies: 155
Views: 15878

Re: Minimum Cross Sectional Area: Question

Skinny, your putting way too much faith in the results of your engine sim.

Randy
by randy331
Mon Feb 17, 2020 10:28 am
Forum: Engine Tech
Topic: LS3 Carbed build
Replies: 423
Views: 67420

Re: LS3 Carbed build

Chad, i was looking at rules for masters of motors for this year and looking at Eric Roycraft winning race engine challenge LS3 with tunnel ram and 2 x carbs. with your LS3 and a compression rule of 12.5:1,do you have an opinion on where your engine would sit in the competition?? hope you don't min...
by randy331
Sat Feb 15, 2020 10:56 pm
Forum: Engine Tech
Topic: Why does a tighter lsa need more compression?
Replies: 140
Views: 14540

Re: Why does a tighter lsa need more compression?

I have a 355 with 10-1 comp I run in my work truck, it has a 204* at .050" duration cam. I did a 383 street engine with 10-1 comp with a 256* at .050" duration cam. Does one of them have the right "dynamic compression" ? Randy Wouldn't one need a whole lot more information on bo...
by randy331
Sat Feb 15, 2020 9:42 am
Forum: Engine Tech
Topic: Minimum Cross Sectional Area: Question
Replies: 155
Views: 15878

Re: Minimum Cross Sectional Area: Question

steve316 wrote: Sat Feb 15, 2020 7:58 am GaryC what is the comparison of angle mill to raise compression or as a after thought?
Steve, have you noticed those that build no actual real engines, or do any testing, and have no data of their own, are the most vocal opposition to those that do build real engines?

Randy
by randy331
Fri Feb 14, 2020 11:32 pm
Forum: Engine Tech
Topic: Why does a tighter lsa need more compression?
Replies: 140
Views: 14540

Re: Why does a tighter lsa need more compression?

I have a 355 with 10-1 comp I run in my work truck, it has a 204* at .050" duration cam.

I did a 383 street engine with 10-1 comp with a 256* at .050" duration cam.

Does one of them have the right "dynamic compression" ?

Randy
by randy331
Fri Feb 14, 2020 7:54 pm
Forum: Engine Tech
Topic: Minimum Cross Sectional Area: Question
Replies: 155
Views: 15878

Re: Minimum Cross Sectional Area: Question

I see the program works that way but in real life, does that work that way? No it doesn't. I did a back to back raise the comp test. Same day on the dyno I pulled the heads and angle milled them enough to raise comp about 1 full point, put the heads back on and re pulled it. There was no noticeable...
by randy331
Thu Feb 13, 2020 8:11 pm
Forum: Engine Tech
Topic: LS3 Carbed build
Replies: 423
Views: 67420

Re: LS3 Carbed build

I think Randy got real familiar with piston speeds playing around with pulling trucks. :D Yes, the piston speeds get high on a lot of pulling trucks for sure. The 421 has been well over 6000 fpm mean piston speed a lot. Just wish we could get the sled speed up to the same as the piston speeds. LOL ...
by randy331
Wed Feb 12, 2020 9:15 pm
Forum: Engine Tech
Topic: 50* Seats and Cam Duration
Replies: 19
Views: 2692

Re: 50* Seats and Cam Duration

Yeah, you have to somewhat be careful of non-vested bystanders. I experienced a little bit of that recently from others wishing to turn overflowz higher and higher on the dyno...it seemed like an easy decision for others to make :lol: Its possible I'm guilty of the above accusation. LOL :D Randy
by randy331
Wed Feb 12, 2020 8:01 pm
Forum: Engine Tech
Topic: 50* Seats and Cam Duration
Replies: 19
Views: 2692

Re: 50* Seats and Cam Duration

Today I picked a couple lobes for the 454 lsx I'm working on. I like to run my pick by some others I value an opinion from before ordering the cam. Randy Did you make a thread here asking for picks? :D Would that be time well spent ?? :) I decided to,... Shut the valve sooner to trap more air!! And...
by randy331
Tue Feb 11, 2020 11:07 pm
Forum: Engine Tech
Topic: 50* Seats and Cam Duration
Replies: 19
Views: 2692

Re: 50* Seats and Cam Duration

Can not answer about the cam question but I am looking at valve events that suits intake valve size, compression, rpm peak, And application, Those are some of the considerations. The application is a big part of it. Ex valve size/seat angles too. Rpm is up at the top of the list before comp for me....
by randy331
Tue Feb 11, 2020 12:31 am
Forum: Engine Tech
Topic: 50* Seats and Cam Duration
Replies: 19
Views: 2692

Re: 50* Seats and Cam Duration

When you use a steeper seat is making the throat bigger than 90% part of the trade off?? No, there is no set throat percentage that comes with the decision to use a steeper seat. The throat percentage is just a result of the decisions on seat angles and widths you decide on that will fit the castin...
by randy331
Mon Feb 10, 2020 10:14 am
Forum: Engine Tech
Topic: Why does a tighter lsa need more compression?
Replies: 140
Views: 14540

Re: Why does a tighter lsa need more compression?

mt-engines wrote: Sat Feb 08, 2020 12:45 am And why do people care what your engine cranks for compression? Im not building air compressors..
I agree.

Randy