Thinking out loud... MSD LS7 vs FAST LS3 Med Runner
02-13-2019, 07:34 AM
#21
I'm going to try the Dart pro 1 280cc as cast heads with the mid length FAST at close to 7500-7600. If the heads are not great Frankenstein has a cnc program for them to flow over the 400 cfm mark. I like the 252 cfm as cast round exhaust ports in that head. they should be good as cast. The better the exhaust the better the torque. Great stock ls3 valve fit right out of the box. 427 ls3 stroker.
Last edited by handyandy496; 02-13-2019 at 07:59 AM.
02-13-2019, 08:18 AM
#22
10 Second Club
Im going to put the sniper low rise on the 333 im building shooting for 7500ish. depends on if the heads will cooperate of course. Literally testing the limits of the stock 243 port with the rocker boss cut and the chamber milled quite a bit.
If i had more budget and an engine dyno i might test the reg ls3 head also and prob a short runner fast. the 250ish cc runner would be pretty great on a higher rpm short stroke setup like that. maybe i can get some more time on this engine and work at it. would be interesting right?
If i had more budget and an engine dyno i might test the reg ls3 head also and prob a short runner fast. the 250ish cc runner would be pretty great on a higher rpm short stroke setup like that. maybe i can get some more time on this engine and work at it. would be interesting right?
02-13-2019, 08:30 AM
#23
I'm going to try the Dart pro 1 280cc as cast heads with the mid length FAST at close to 7500-7600. If the heads are not great Frankenstein has a cnc program for them to flow over the 400 cfm mark. I like the 252 cfm as cast round exhaust ports in that head. they should be good as cast. The better the exhaust the better the torque. Great stock ls3 valve fit right out of the box. 427 ls3 stroker.
But I decided to give the Haymakers a go since they are good for 400cfm out of the box with the 2.165" valve (but it's a +.300" LS7 length since it's an 11 degree head).
02-13-2019, 08:41 AM
#24
Im going to put the sniper low rise on the 333 im building shooting for 7500ish. depends on if the heads will cooperate of course. Literally testing the limits of the stock 243 port with the rocker boss cut and the chamber milled quite a bit.
If i had more budget and an engine dyno i might test the reg ls3 head also and prob a short runner fast. the 250ish cc runner would be pretty great on a higher rpm short stroke setup like that. maybe i can get some more time on this engine and work at it. would be interesting right?
If i had more budget and an engine dyno i might test the reg ls3 head also and prob a short runner fast. the 250ish cc runner would be pretty great on a higher rpm short stroke setup like that. maybe i can get some more time on this engine and work at it. would be interesting right?
My TEA 243s have a 229cc port. They have no issue at 7400 on my 346. Even with a 227 LSL lobe intake. When I had an EPS 234/242 cam, it pulled even better to 7400.
02-13-2019, 03:06 PM
#26
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02-21-2019, 11:52 AM
#29
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Measured the runner length on the mid runner ls3 fast over the weekend. It measures 7.25". The cathedral msd i have which is probably similar to the ls7 msd measured 7.5".
Hopefully that info helps someone
Hopefully that info helps someone
02-25-2019, 11:48 AM
#35
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Originally Posted by JakeFusion
I think they measure from the bellmouth to the end of the port.
02-25-2019, 01:33 PM
#36
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I would think runner length would be measured through an imaginary line down the center of the port, if that's possible.
02-25-2019, 06:28 PM
#37
You guy's wanna do something? Measure the airflow or cfm of any of these intakes runners with heads attached.....You guy's have the runner length down to a science for RpM...contine on.
02-25-2019, 06:32 PM
#38
Found out gen 5 LT1 heads can & will fit a Ls block.... Now the question is how to utilize them. Weld the DI port. High lift short duration? The 6.6 crank 8k?
Last edited by Smokey B; 02-25-2019 at 06:38 PM.
02-25-2019, 08:33 PM
#39
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Originally Posted by Smokey B
You guy's wanna do something? Measure the airflow or cfm of any of these intakes runners with heads attached.....You guy's have the runner length down to a science for RpM...contine on.
02-25-2019, 09:13 PM
#40
Darth may i ask what was seen for the given size port cfm and intake attached? Key being FAST has adjustable runners, match cfm & runner length for a given rpm. Shorta like a Holley low pro, just with a FAST ported (runner length dependent)? Should match most or any rpm as is without porting. Then we Run into plenum area. Yet i ask what is the plenum area for ITB? It's just moving air?
Last edited by Smokey B; 02-25-2019 at 09:25 PM.