Large bore lt1 block
Registered User
Joined: Jul 2001
Posts: 752
From: Double Oak TX
Re: Large bore lt1 block
Originally Posted by rskrause
A 450ci small block needs over $5,000 in heads and valvetrain parts to support it.
Rich
Rich
Planning on my next engine to be a real duzie and no great rush. Maybe I shouldn't have said that.....The weather is finally turning to better air and have a tendency to drive a little bit harder.
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Joined: Dec 2000
Posts: 766
From: GARDNERS,PA
Re: Large bore lt1 block
If you wanted to keep the opti a SBC would be some trouble, but if you wanted to go with a aftermarket ECU this would all be much much easier. 450cubes and SB2.2 heads with a sheetmetal intake would make it easy.
Steve
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Joined: Dec 1969
Posts: 10,745
From: Buffalo, New York
Re: Large bore lt1 block
Originally Posted by Denny McLain
Probably have that much now in heads and valvetrain, mostly because the heads were ported twice with larger valves each time. Not counting about four different sets of springs to find the ones the car liked and seem to last.
Planning on my next engine to be a real duzie and no great rush. Maybe I shouldn't have said that.....The weather is finally turning to better air and have a tendency to drive a little bit harder.
Planning on my next engine to be a real duzie and no great rush. Maybe I shouldn't have said that.....The weather is finally turning to better air and have a tendency to drive a little bit harder.
Yeah, a big inch small block truly is an expensive proposition. There is no point in building one without also having the needed top end and valve train. Other than bragging rights, if you used "typical" LT1 components it would not be a very good combo.
Rich
Registered User
Joined: Aug 2005
Posts: 416
From: Tampa, FL
Re: Large bore lt1 block
why use an opti ignition when a trigger and a dfi system would be a 1000 times better? as for SB2 HEADS HERES A DEAL FOR YOU!
http://www.need2speed.com/vb_forums/...ad.php?t=19460
http://www.need2speed.com/vb_forums/...ad.php?t=19460
Registered User
Joined: Dec 2000
Posts: 766
From: GARDNERS,PA
Re: Large bore lt1 block
Honestly, The only downside of the opti system is the High Tension side and LTCC takes care of that. The 7K limit can be an issue if your spinning higher. Other than that fuel is fuel, 12.8 AFR is 12.8 AFR and 36 degrees of advance is 36 degrees of advance. I don't see how there's any HP gain with $1,200 worth of Big Stuff, DFI, Fast, or anything else.
Steve
Steve
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Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
Re: Large bore lt1 block
There's something to be said for adjusting injector timing relative to inlet air flow, at least MoTeC thinks there is.
Is it important to the average builder? Probably not, but its something that can be used to optimze performance, emissions and fuel efficiency.
Injection Timing - With a synced engine which uses 1 injector in each intake manifold runner, it is possible to phase the firing of the injector so that it only sprays during the intake stroke. This allows you to introduce fuel into the intake stream precisely at the time when the airflow into the cylinder is the greatest providing the best possible atomization and the highest efficiency. MoTeC offers a user definable 2 or 3 dimensional Injection Timing adjustment table so that you can accurately match any engine's injection timing demands. Tuners can select either beginning or end of injection on which to base the timing table. This allows the tuner the ultimate in adjustability to suit any engine combination.
Registered User
Joined: Nov 2004
Posts: 1,374
From: Raleigh, NC
Re: Large bore lt1 block
Originally Posted by Injuneer
There's something to be said for adjusting injector timing relative to inlet air flow, at least MoTeC thinks there is.
Is it important to the average builder? Probably not, but its something that can be used to optimze performance, emissions and fuel efficiency.
Is it important to the average builder? Probably not, but its something that can be used to optimze performance, emissions and fuel efficiency.
There's alot to be said for that kind of tuning potential though
Registered User
Joined: Dec 2000
Posts: 766
From: GARDNERS,PA
Re: Large bore lt1 block
Fred,
I'll conceed to your point that in some max effort combinations individual injector timing and individual cylinder timing can help. In fact a friend of mine that runs NMRA EFI Renegade retards timing and adds fuel to one cylinder to keep it alive. That being said, most typical street/strip combos, and most tuners wouldn't normally have to delve into this stuff on a NA application.I suppose my point is that a big SBC could be managed perfectly fine with a properly tuned GM SEFI system, and that could be more cost effective and produce results on par with the aftermarket guys. Using stock PCM would also clean up the underhood wiring. The only hurdle is mounting to optical portion of the opti, then the rest is cake.
Steve
I'll conceed to your point that in some max effort combinations individual injector timing and individual cylinder timing can help. In fact a friend of mine that runs NMRA EFI Renegade retards timing and adds fuel to one cylinder to keep it alive. That being said, most typical street/strip combos, and most tuners wouldn't normally have to delve into this stuff on a NA application.I suppose my point is that a big SBC could be managed perfectly fine with a properly tuned GM SEFI system, and that could be more cost effective and produce results on par with the aftermarket guys. Using stock PCM would also clean up the underhood wiring. The only hurdle is mounting to optical portion of the opti, then the rest is cake.
Steve
Registered User
Joined: Jun 2003
Posts: 203
From: York, PA
Re: Large bore lt1 block
Steve,
I think there is a guy a couple of clicks up the road (in Y-springs) that can make that 421 a reality in a stock block
I swear he has aliens working for him...
Give me a call sometime, My tuning schedule is booked and could use some help.
Dennis
I think there is a guy a couple of clicks up the road (in Y-springs) that can make that 421 a reality in a stock block
I swear he has aliens working for him...Give me a call sometime, My tuning schedule is booked and could use some help.
Dennis
Registered User
Joined: Mar 2002
Posts: 3,082
From: San Juan PR
Re: Large bore lt1 block
After giving much debate... why do it with a gen 2???? why not do a gen 3/4? it already solves many of the problems we face and 427 is just readily available. Factory programming is at its greatest and its really a lot cheaper and neater than any fast/motec system....
In the end .. aftermarket blocks and heads will be more expensive.. when you get to see a really good system for how much money.. a crate ls7 is really really tempting and good, specially when you can still use a gen 2 computer with a simple 58x to 24x crank sensor signal converter...
In the end .. aftermarket blocks and heads will be more expensive.. when you get to see a really good system for how much money.. a crate ls7 is really really tempting and good, specially when you can still use a gen 2 computer with a simple 58x to 24x crank sensor signal converter...
Banned
Joined: Jan 2002
Posts: 1,935
From: Mobile, Ala..USA
Re: Large bore lt1 block
My thoughts, if they mean anything
sprintcars used "batch" type njectionwith fuel sitting on the vlave waiting for it to open, seems like they make GOOD power with Hilborns.
Is a 4.040 bore with a 4 inch stroke and a 6 inch rod to safe to street drive? Seems to me that would be the limit to a street Lt1, 410 inches.
David
sprintcars used "batch" type njectionwith fuel sitting on the vlave waiting for it to open, seems like they make GOOD power with Hilborns.
Is a 4.040 bore with a 4 inch stroke and a 6 inch rod to safe to street drive? Seems to me that would be the limit to a street Lt1, 410 inches.
David