ALL F'ing LT5 problems solved - ZR-1 Net Registry Forums

8upZR1 · 04-14-2008

Hello All,

It has been a while, long while. Seems finally computer and mechanical toys are behaving nicely, well almost....

I have the ultimate solution for the Lt5, and the problems, it is currently in fabrication. I have thrown away everything, and I do mean EVERYTHING that bolts onto the cylinder heads of our cars, except that block thingy out of aluminum. I have machined the surfaces of the cylinder head's intake flange, so that now they are 90 to the deck, a la old sbc. I have purchased an SBC2.2 spider and am fabbing the connections now. Yes, a carb. Take you 16 injectors and.........

An MSD E-curve has been cut up and a drive system has been fabbed. Mandrel from passenger side intake cam runs the e-curve direct. The worst part was that I had to throw away that little rubber round thingy, and run remote oil filter.

F'you Lt5. Anybody wanna buy an original wiring harness???

I have a screw driver to control spark and fuel, a wife and child to control me. Life almost seems good.......if the boy would go to sleep, I could control my wife with my screwdriver, J.K.

What size carb does the community think the LT5 wants. It'll probably be like 396 CID so I'm thinkin 750. Heads are ported, I like 8000 RPM, 750 cfm should be plenty for street play.

cuisinartvette · 04-14-2008

I gotta see this.

Pics?

396 at 8k may want a little more than that but if all you have is a 750DP you can always jet up. HP series carbs are pretty nice.

flyin ryan · 04-14-2008

Quote:

Originally Posted by 8upZR1

It'll probably be like 396 CID so I'm thinkin 750. Heads are ported, I like 8000 RPM, 750 cfm should be plenty for street play.

well i would say no bigger than 750 for sure, but C.I.D. & R.P.M. help, but what kind of power/torque do you think you'll end up at? sounds like a cool deal to me, a bit of work but trick stuff always is.

tccrab · 04-14-2008

Quote:

Originally Posted by cuisinartvette

I gotta see this.

Pics?

396 at 8k may want a little more than that but if all you have is a 750DP you can always jet up. HP series carbs are pretty nice.

I gotta see this.

A 750 Double Pumper should breath enough, even at 8000rpm.
A buddy of mine has one on his 383 stroker and it breaths just fine, of course, it's not rotating at 8000 rpms, but..... hmmmm.....

As I'm sitting here thinking about this, I'm amazed at how complicated this kind of project might become.
Seems to me that the ECM still needs to be there so that the dash will work, things like speedo & gauges. What about VATS? At least some small part of the AC system is dependant on input from the ECM.
What about emissions, is GA a no visual inspection state?

Wow.
Just Wow.

Tom

XfireZ51 · 04-15-2008

Why would you defile an LT-5 with a carb?

tccrab · 04-15-2008

Quote:

Originally Posted by XfireZ51

Why would you defile an LT-5 with a carb?

About 2 years ago he had a head gasket go because somebody used the wrong kind of coolant.
It would seem that it's been an uphill battle thus far.

I wish him the best of luck. May his troubles be cured.

Tom

Pete · 04-15-2008

What problems does the LT5 have that you are trying to solve?

Also the weak link our LT5 has for 8K rpm is our cam chains,break one of those and then you will see some real LT5 problems.

Also a well ported stock plenum is not our HP restriction i'm pretty sure it's in the cam specs. i will find out in a few weeks about the cam specs,HP with different intakes.

Is this SB 2 intake that much better then a Hogan intake?

How long are the runners of the SB2 intake?
Who is doing the work?
I wish and hope this works for you can you let us know before and after results.
I'm very interested and you got my attention.

Pete

8upZR1 · 04-15-2008

Why would you continue to defile your LT-5 motor with GM technology from the mid to late 80's? It's hella $$$$, prices aren't going down, stock is limited, and availability is weeks away for anything. A set of main bearings ( a set of 5 shells) is going for $800. Throttle body $1500.

Why would you defile an LT-5 with a technology from the 60's ( 4 bbl holley)??? Cause its been around for 100 years (carbs in general), Nascar boys have been pouring $$$$$$$$$ into the perfection of the 4 bbl intake for high rpm 350'ish V-8's for years and an intake for a SB2.2 has 4.4" port spacing and is made for turning rpm's with power. Also, a slightly used, but proffesionally ported spider is only $300, and distribution is dead on cause the firing order is the same.

I refuse to spend mega $$$ for crap (80's crap at that). If you do, give me a call, I've got a whole ZR-1 worth of it. I am getting rid of EVERYTHING. So I will make a new wiring harness with one single spool of wire from Pep boys. Manual controls for A/C, Fan, etc. Throwing away Cluster, abs, VATS, ALDLDLDLDLD, EVERYTHING! This project is under tight budget constraints but I think with some sly parts selection everything, including 4.030 bores and 3.88 stroke crank will come under 7K. Thats the goal anyway.

Pics will come, the car is being LIGHTENED currently, i.e. chassis stripped and CLEANED. Once back Ill shoot some photots.

Zr1 Destroyer · 04-15-2008

Quote:

Originally Posted by 8upZR1

Hello All,

It has been a while, long while. Seems finally computer and mechanical toys are behaving nicely, well almost....

I have the ultimate solution for the Lt5, and the problems, it is currently in fabrication. I have thrown away everything, and I do mean EVERYTHING that bolts onto the cylinder heads of our cars, except that block thingy out of aluminum. I have machined the surfaces of the cylinder head's intake flange, so that now they are 90 to the deck, a la old sbc. I have purchased an SBC2.2 spider and am fabbing the connections now. Yes, a carb. Take you 16 injectors and.........

An MSD E-curve has been cut up and a drive system has been fabbed. Mandrel from passenger side intake cam runs the e-curve direct. The worst part was that I had to throw away that little rubber round thingy, and run remote oil filter.

F'you Lt5. Anybody wanna buy an original wiring harness???

I have a screw driver to control spark and fuel, a wife and child to control me. Life almost seems good.......if the boy would go to sleep, I could control my wife with my screwdriver, J.K.

What size carb does the community think the LT5 wants. It'll probably be like 396 CID so I'm thinkin 750. Heads are ported, I like 8000 RPM, 750 cfm should be plenty for street play.

I have an sb2 intake sitting in my garage and would be waaaay off as far as the ports are concerned, but I guess anything is possible with enough fab work...lol! Post some pics up when you finish!?!?

Depending on your head flow I would say you'll atleast need a 1000cfm carb to carry those rpms up top.

-=Jeff=- · 04-15-2008

Sounds like a cool project.. Would like to see some pictures of it

Are you selling any of the OEM stuff to fund the project??

04-14-2008	#1
8upZR1 Join Date: Jun 2006 Location: Thunderbolt, Ga. Posts: 253	ALL F'ing LT5 problems solved Hello All, It has been a while, long while. Seems finally computer and mechanical toys are behaving nicely, well almost.... I have the ultimate solution for the Lt5, and the problems, it is currently in fabrication. I have thrown away everything, and I do mean EVERYTHING that bolts onto the cylinder heads of our cars, except that block thingy out of aluminum. I have machined the surfaces of the cylinder head's intake flange, so that now they are 90 to the deck, a la old sbc. I have purchased an SBC2.2 spider and am fabbing the connections now. Yes, a carb. Take you 16 injectors and......... An MSD E-curve has been cut up and a drive system has been fabbed. Mandrel from passenger side intake cam runs the e-curve direct. The worst part was that I had to throw away that little rubber round thingy, and run remote oil filter. F'you Lt5. Anybody wanna buy an original wiring harness??? I have a screw driver to control spark and fuel, a wife and child to control me. Life almost seems good.......if the boy would go to sleep, I could control my wife with my screwdriver, J.K. What size carb does the community think the LT5 wants. It'll probably be like 396 CID so I'm thinkin 750. Heads are ported, I like 8000 RPM, 750 cfm should be plenty for street play. __________________ IT IS THE FATE OF THE INNOCENT TO MEET WITH DEATH!!!

04-14-2008	#2
cuisinartvette Join Date: Aug 2005 Location: San Fernando Valley, CA. Posts: 896	Re: ALL F'ing LT5 problems solved I gotta see this. Pics? 396 at 8k may want a little more than that but if all you have is a 750DP you can always jet up. HP series carbs are pretty nice. __________________ 1990 ZR1, 142,000 miles-Black on black 4.09's Haibeck chip, 3"exh, K&N, meth inj.

04-15-2008	#5
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,700	Re: ALL F'ing LT5 problems solved Why would you defile an LT-5 with a carb?

04-15-2008	#7
Pete Join Date: Dec 2003 Location: Chicagoland,IL Posts: 2,679	Re: ALL F'ing LT5 problems solved What problems does the LT5 have that you are trying to solve? Also the weak link our LT5 has for 8K rpm is our cam chains,break one of those and then you will see some real LT5 problems. Also a well ported stock plenum is not our HP restriction i'm pretty sure it's in the cam specs. i will find out in a few weeks about the cam specs,HP with different intakes. Is this SB 2 intake that much better then a Hogan intake? How long are the runners of the SB2 intake? Who is doing the work? I wish and hope this works for you can you let us know before and after results. I'm very interested and you got my attention. Pete __________________ '91 #1635 PoloGreen 350 LT5 11.09 @ 129.27 11.04 @ 128.86 474RWHP 400RWTQ http://www.youtube.com/watch?v=SFNFOhGGlR4 http://www.youtube.com/watch?v=ZlRIOMwaDYY https://sites.google.com/site/peteszr1garage

04-15-2008	#8
8upZR1 Join Date: Jun 2006 Location: Thunderbolt, Ga. Posts: 253	Re: ALL F'ing LT5 problems solved Why would you continue to defile your LT-5 motor with GM technology from the mid to late 80's? It's hella $$$$, prices aren't going down, stock is limited, and availability is weeks away for anything. A set of main bearings ( a set of 5 shells) is going for $800. Throttle body $1500. Why would you defile an LT-5 with a technology from the 60's ( 4 bbl holley)??? Cause its been around for 100 years (carbs in general), Nascar boys have been pouring $$$$$$$$$ into the perfection of the 4 bbl intake for high rpm 350'ish V-8's for years and an intake for a SB2.2 has 4.4" port spacing and is made for turning rpm's with power. Also, a slightly used, but proffesionally ported spider is only $300, and distribution is dead on cause the firing order is the same. I refuse to spend mega $$$ for crap (80's crap at that). If you do, give me a call, I've got a whole ZR-1 worth of it. I am getting rid of EVERYTHING. So I will make a new wiring harness with one single spool of wire from Pep boys. Manual controls for A/C, Fan, etc. Throwing away Cluster, abs, VATS, ALDLDLDLDLD, EVERYTHING! This project is under tight budget constraints but I think with some sly parts selection everything, including 4.030 bores and 3.88 stroke crank will come under 7K. Thats the goal anyway. Pics will come, the car is being LIGHTENED currently, i.e. chassis stripped and CLEANED. Once back Ill shoot some photots. __________________ IT IS THE FATE OF THE INNOCENT TO MEET WITH DEATH!!!

04-15-2008	#10
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,161	Re: ALL F'ing LT5 problems solved Sounds like a cool project.. Would like to see some pictures of it Are you selling any of the OEM stuff to fund the project?? __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978