Differences between LS3 427 stroker and LS7
08-04-2017, 12:24 AM
#42
Breather hole The 1" breather hole I drill, identical to those on the original LS1, has less area than the cast in breather holes. I'd have to say that you would get most but not all the benefits of the cast in breather holes. Recall what I said about the blocks in long duration high output use cracking from the cast in breather holes to the cam bearings.
Steve,
I have one of your sleeved 5.3L blocks. Just a clarification on the above statement. You offer the option of boring a hole through the main bearing bulkheads, correct? Is that different than the bolded comment above? When you add that hole, it would regain any loss as you describe, correct?
Thanx!
I have one of your sleeved 5.3L blocks. Just a clarification on the above statement. You offer the option of boring a hole through the main bearing bulkheads, correct? Is that different than the bolded comment above? When you add that hole, it would regain any loss as you describe, correct?
Thanx!
__________________
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
08-04-2017, 12:27 AM
#43
LSx I'd say for your build you are better off taking the route you are going. You fall into the catagory of the folks who need better than a factory casting for what they are doing. Be less expensive as well if you can handle the extra weight on the front end.
Steve
Steve
So if the end goal is a 8.5 1/4 mile turbo non daily driven full weight street car that uses pump gas on the street and a meth kit at the track, is the LSX bow tie block PN 19260093 complete overkill? Reliability is important, but it's not like I'm tracking the car every weekend and I don't want a 25 point cage. If overkill, what should I step down to that is reliable? I don't want to have to ever pull the motor once it's put together. At first, an LSX block with 6 bolt heads sounded like a good reliable solution for a twin turbo street car on pump gas, but not sure how much power I can even get to the ground on a 26" tire/4th gen camaro setup. What's the difference in cost of say the combo below to what you would recommend given my goals?
LSX block, PN 19260093
Compression ratio 9.0:1
4.125 bore
Diamond -23cc Dish (#112-11595R1)
Mahle 4.127" -4cc Flat-Top
Oliver Billet 6.125", ARP 2000 Bolts
Callies Dragonslayer, Wet Sump 4.000-inch stroke
PRC 6-Bolt 285cc LS7 with Titanium Intake, Stainless Exhaust Valves
Twin turbo and all the supporting mods
LSX block, PN 19260093
Compression ratio 9.0:1
4.125 bore
Diamond -23cc Dish (#112-11595R1)
Mahle 4.127" -4cc Flat-Top
Oliver Billet 6.125", ARP 2000 Bolts
Callies Dragonslayer, Wet Sump 4.000-inch stroke
PRC 6-Bolt 285cc LS7 with Titanium Intake, Stainless Exhaust Valves
Twin turbo and all the supporting mods
__________________
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
08-04-2017, 11:37 AM
#44
The 1" breather hole I drill, identical to those on the original LS1, has less area than the cast in breather holes. I'd have to say that you would get most but not all the benefits of the cast in breather holes. Recall what I said about the blocks in long duration high output use cracking from the cast in breather holes to the cam bearings.
08-08-2017, 10:38 AM
#45
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The other main difference, of course, is in the cylinder heads. The specific beauty in the LS7 cylinder heads are the intake flows. You can run LS3 heads on an LS7 block, but the LS7 heads will only fit the LS7 block.
A lot of the LS7 was derived with lessons learned from the C5-R, and the LS7 continued forward to influence the new Gen V LT engines: dry-sump oiling, 1.8 rockers, the same 12° valve angle, forged-steel crankshaft, etc.
A lot of the LS7 was derived with lessons learned from the C5-R, and the LS7 continued forward to influence the new Gen V LT engines: dry-sump oiling, 1.8 rockers, the same 12° valve angle, forged-steel crankshaft, etc.
08-08-2017, 11:12 AM
#46
The other main difference, of course, is in the cylinder heads. The specific beauty in the LS7 cylinder heads are the intake flows. You can run LS3 heads on an LS7 block, but the LS7 heads will only fit the LS7 block.
A lot of the LS7 was derived with lessons learned from the C5-R, and the LS7 continued forward to influence the new Gen V LT engines: dry-sump oiling, 1.8 rockers, the same 12° valve angle, forged-steel crankshaft, etc.
A lot of the LS7 was derived with lessons learned from the C5-R, and the LS7 continued forward to influence the new Gen V LT engines: dry-sump oiling, 1.8 rockers, the same 12° valve angle, forged-steel crankshaft, etc.
08-08-2017, 04:36 PM
#47
Each has it's own intake: MSD,FAST,Super Vic,CID, etc.... Fast Ls3 is the difference in which different runners can be used. Oh yea the Ls3 cross ram by Edelbrock. But they do sell a adapter plate to fit Ls7 heads to a Ls3 intake.
08-08-2017, 07:02 PM
#49
CBM
http://store.custombuiltmotors.com/i...-adapters.html
Sorry about the time frame trying to get my snap back from Moonshining it up last night.
http://store.custombuiltmotors.com/i...-adapters.html
Sorry about the time frame trying to get my snap back from Moonshining it up last night.
08-09-2017, 09:47 AM
#51
No problem, they've been out for a while like 3 yrs, seems to be pretty good. Would save a little cash in not having to purchase another intake if a person were to change heads. I just have a things I would like to know. The Ls7 heads generally has a smaller port in height. But it's a nice thought and part for us.
Looking this intake over, may not be a CID but neither is the $.
https://www.briantooleyracing.com/ed...-4500-efi.html
Looking this intake over, may not be a CID but neither is the $.
https://www.briantooleyracing.com/ed...-4500-efi.html
08-10-2017, 07:47 AM
#53
Thats a misleading statement. GM and most aftermarket LS7 heads will fit any LSx block with a 4.125" minimum bore. There are however small and medium bore LS7 heads on the market
08-10-2017, 08:43 AM
#54
Why a dart block over an LSX block? Is it because there is more machine work involved taking the LSX block to 3.625 stroke an 4.125 bore?
What about a de-stroked LS7, cutting the LS7's stroke from 4.000 to 3.625 inches and maintaining the stock 4.125-inch bores. It then has a 1.14 bore/stroke ratio. This puts it as an over-square configuration for high-rpm horsepower. Ideal for a race engine, but aren't these over-square configurations not as good for street applications, which is what i'm shooting for. I want a reliable, low torque, 1000-1200hp street car setup that I can take to the track and run 8.60's all day and I don't want to have to run insane boost to get it there or have to run pump E85 all the time. Yes, higher displacement means less boost but doesn't it also mean having to go to a 4" stroke in most applications? I keep hearing "you only need 4 bolt heads". Why not get 6 bolt heads to be safe?
So what is the proper bore, stroke combo to go with for a street setup, what iron block would you use to get there? Is this a ask 5 different people get 5 different answers kind of thing? Every setup has trade offs, I'm just looking for the best answer, if there even is one.
3.819" bore 4.000" stroke: 381.9ci or 6.3L
4.125" bore 3.622" stroke: 387.2ci or 6.3L
4.130" bore 3.750" stroke: 402.1ci or 6.6L
4.000" bore 4.000" stroke: 402.1ci or 6.6L
4.125" bore 3.819" stroke: 408.3ci or 6.7L
4.065" bore 4.000" stroke: 415.3ci or 6.8L
4.125" bore 4.000" stroke: 427.6ci or 7.0L
What about a de-stroked LS7, cutting the LS7's stroke from 4.000 to 3.625 inches and maintaining the stock 4.125-inch bores. It then has a 1.14 bore/stroke ratio. This puts it as an over-square configuration for high-rpm horsepower. Ideal for a race engine, but aren't these over-square configurations not as good for street applications, which is what i'm shooting for. I want a reliable, low torque, 1000-1200hp street car setup that I can take to the track and run 8.60's all day and I don't want to have to run insane boost to get it there or have to run pump E85 all the time. Yes, higher displacement means less boost but doesn't it also mean having to go to a 4" stroke in most applications? I keep hearing "you only need 4 bolt heads". Why not get 6 bolt heads to be safe?
So what is the proper bore, stroke combo to go with for a street setup, what iron block would you use to get there? Is this a ask 5 different people get 5 different answers kind of thing? Every setup has trade offs, I'm just looking for the best answer, if there even is one.
3.819" bore 4.000" stroke: 381.9ci or 6.3L
4.125" bore 3.622" stroke: 387.2ci or 6.3L
4.130" bore 3.750" stroke: 402.1ci or 6.6L
4.000" bore 4.000" stroke: 402.1ci or 6.6L
4.125" bore 3.819" stroke: 408.3ci or 6.7L
4.065" bore 4.000" stroke: 415.3ci or 6.8L
4.125" bore 4.000" stroke: 427.6ci or 7.0L
Last edited by 5.7stroker; 08-10-2017 at 09:42 AM.
08-10-2017, 09:21 AM
#55
Call LIL JOHN the turbo specialist for his recommendation he does this in his Sleep. And you'd get only one answer not 5 different ones Lol. You are on a forum. LMAO. Just messing with you 5.7.
Last edited by Patron; 08-10-2017 at 09:27 AM.
08-10-2017, 02:01 PM
#58
You'll definitely get a lot of different answers on the forum. All in what each person likes. I personally like a small stroke higher revving engine for a turbo setup. It really all comes down to budget and long term goals. You cant go wrong with an LS7 headed 4.125 x 4.00 engine though. I would personally choose the LS next iron block if I was in your situation.