1969 LT1 Clone
Racer
Joined: Feb 2001
Posts: 377
Likes: 0
Re: 1969 LT1 Clone (Chuck Harmon)
[QUOTE] Just clears the stock hood by about 3/4 of an inch. [QUOTE]
Excellent, thanks, good to know.
Thanks Chuck, I have the 130, I bought a case for a trial. It seems to be more cost effective to pick up 110 race fuel and add 1 1/4 gals to a tank. For me anyway. The pinging is really bad if I don't. I've had to down tune a little to avoid it. I keep a couple of cans of the 130 in the trunk :crazy:, jack storage area, in case I'm out for more than a tanks drive. I will have to look into what you say. Is this the case that slowly pouring water in can help clean it out? The car runs great and pretty strong regardless.
Jon
Excellent, thanks, good to know.
Jon,The L46 and the LT1 are really only 10.5:1 cr. I never had any real problem with detonation if I used premium fuel. If I needed more octane, I have been very impressed with the "Supreme Lead 130". A quart per tank will raise 91 octane to 95-96 octane.If you block the heat riser passage on the intake, you will significantly lower the octance requirement. An oil splash shield under the intake will also help. Ifpinging or detonation is a problem, I would suspect carbon buildup in the combustion chamber raising the effective compression ratio and glowing like little charcoal briquettes.Chuck
Jon
Racer
Joined: Feb 2001
Posts: 377
Likes: 0
Re: 1969 LT1 Clone (Chuck Harmon)
Chuck, I forgot to ask. are you familar with Corvette Clinic on W.San Carlos?
Would it be a good alternative to the parts houses on the east coast. Would you know if they have a catalog?
Jon
Would it be a good alternative to the parts houses on the east coast. Would you know if they have a catalog?
Jon
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: 1969 LT1 Clone (Jon69L46)
Chuck, I forgot to ask. are you familar with Corvette Clinic on W.San Carlos?
Would it be a good alternative to the parts houses on the east coast. Would you know if they have a catalog?
Jon
Would it be a good alternative to the parts houses on the east coast. Would you know if they have a catalog?
Jon
Matt and Keith at the Corvette Clinic are great guys and very helpful! They have done a great job for me getting parts at or below Ecklers' costs. Even though their store isn't that big, I swear that they could assemble several complete cars of each c1, c2, etc...
I don't think they have a catalog, but if you ask them about a part from anyone else's catalog they know what you are talking about, probably have it, or can get it pretty quick.
Chuck
Melting Slicks
Joined: Oct 2001
Posts: 2,062
Likes: 1,360
From: Halifax, Nova Scotia, Canada
Re: 1969 LT1 Clone (Robert N)
I agree that the L46 is faster to 90 than the LT-1 in the article, but I have a tough time believing that from where I sit.
I think Chuck is right about the tuning.
Other than that, the LT-1 intake was a dual plane and a single plane will make a drastic difference.
"Dual plane manifolds have shown to be more throttle and torque responsive at low and mid range rpm levels than most (but not all) single plane manifold designs." "[A single plane] has drawbacks, particularly as the number of cylinders increase. Intake pulses start to overlap, and that can mean that a cylinder will "rob" the cylinder following it in the firing order of charge- if they are located close to each other in the block."
Other than that, the LT-1 intake was a dual plane and a single plane will make a drastic difference.
"Dual plane manifolds have shown to be more throttle and torque responsive at low and mid range rpm levels than most (but not all) single plane manifold designs." "[A single plane] has drawbacks, particularly as the number of cylinders increase. Intake pulses start to overlap, and that can mean that a cylinder will "rob" the cylinder following it in the firing order of charge- if they are located close to each other in the block."
The stock LT1 dual plane is much better. Especially low/mid range.
In the 1/4 mi, there was little difference, other than you could control wheel spin easier with the LT1 intake. On/off the throttle was more responsive.
The best improvement was the addition of the Holley 750DP.
A common problem with adding performance items is getting the tuning right.
I think I was a couple years before I had it "all".
Good performance, good low end drivability, little gas smell, and not too bad milage.
There are many areas to tune in a Holley, and I don't mean jets. Jets are one of the last things to change.
Barry
Drifting
Joined: Jul 2002
Posts: 1,735
Likes: 14
From: Tucson AZ
Re: 1969 LT1 Clone (micks69)
Looks good Mick. I bought my '70 Vert L46/350 hp and it was LT-1 cloned. Hood, intake, carb, open element air cleaner, cam, 370's. One part of me says put it back to stock but that would take $ and I love it the way it is!!
Melting Slicks
Joined: Mar 1999
Posts: 2,845
Likes: 2
From: Apex NC
Re: 1969 LT1 Clone (micks69)
I always wondered what the definition of "streetable" means? If it means drives good then thats what I want. That leaves everything else or not "streetable" what is that? Goes really fast but not reliably or often? I want something that looks cool, is reliable and goes faster than most other stock vettes.
I've seen too many guys build up motors with mismatched components that are difficult or near impossible to tune, won't idle below 1200 rpm, and have no power below 4500 rpm. Then they get frustrated when the car doesn't perform up to their expectations. The LT-1 conversion is straightforward and should provide a reasonably streetable motor, but less so than the L-46.
:cheers:
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Re: 1969 LT1 Clone (micks69)
I'm open to suggestions!
80508 carb that you currently have (if it is a 80508).. This should solve your idle problem and add some power!!
:cheers:
Olivier
[Modified by GrandSportC3, 9:11 PM 10/7/2002]
You are correct I do have the 80508 but I cant return it now. Any other way to improve the performance? I really miss the secondaries opening on the q-jet. :confused:
80508 carb that you currently have (if it is a 80508).. This should solve your idle problem and add some power!!
:cheers:
Olivier
[Modified by GrandSportC3, 9:11 PM 10/7/2002]
You are correct I do have the 80508 but I cant return it now. Any other way to improve the performance? I really miss the secondaries opening on the q-jet. :confused:
:cheers:
Olivier
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Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: 1969 LT1 Clone (sb69coupe)
sb69coupe,
I agree with your definition. I will say though that having driven my L46 for many, many miles, I was no less pleased with the streetability of the factory spec LT1. A little more nervous feeling down low, but so eager and willing to be revved up high. Definately a bit more power, but not a huge difference. A well tuned double pumper's instaneous throttle response really wakes it up giving the illusion of even more power.
Minimum of 3.70 gears or a wide ratio trans if lower numerical rear end are much desired with the LT1.
Chuck
I agree with your definition. I will say though that having driven my L46 for many, many miles, I was no less pleased with the streetability of the factory spec LT1. A little more nervous feeling down low, but so eager and willing to be revved up high. Definately a bit more power, but not a huge difference. A well tuned double pumper's instaneous throttle response really wakes it up giving the illusion of even more power.
Minimum of 3.70 gears or a wide ratio trans if lower numerical rear end are much desired with the LT1.
Chuck
Thread Starter
Burning Brakes
Joined: Aug 2001
Posts: 1,160
Likes: 3
From: Greensboro NC
Re: 1969 LT1 Clone (Chuck Harmon)
Thanks for all the replies!
After reading them all and calling summit racing which is only 35 miles away. Heres what I'm going to do.
#1 Go with the performer intake (should fit, let me know if it doesnt)
#2 Try the the carb I have now and a softer secondary spring.
#3 If all else fails put it back to original
That should keep me busy for a few weekends and evenings!
After reading them all and calling summit racing which is only 35 miles away. Heres what I'm going to do.
#1 Go with the performer intake (should fit, let me know if it doesnt)
#2 Try the the carb I have now and a softer secondary spring.
#3 If all else fails put it back to original
That should keep me busy for a few weekends and evenings!
Drifting
Joined: Jul 2002
Posts: 1,735
Likes: 14
From: Tucson AZ
Re: 1969 LT1 Clone (micks69)
Mick - When putting on the Performer intake beware of the additional height. I put the Performer intake and Performer 600 carb in and had a hell of a time getting the air cleaner to fit with the LT-1 hood. You've got the L46 hood which (I believe) affords even less room (1/2" or so?). I've got a nice spider in the middle of my hood for not paying attention to this. :mad
I wound up having to go with a 2" drop base and a 2 3/8" element and it's TIGHT!
Bob
I wound up having to go with a 2" drop base and a 2 3/8" element and it's TIGHT!
Bob
Thread Starter
Burning Brakes
Joined: Aug 2001
Posts: 1,160
Likes: 3
From: Greensboro NC
Re: 1969 LT1 Clone (BobJ)
I went out today and changed the intake to a dual plane and went with softer springs in the secondaries. It made a great difference. Thanks for all the great suggestions! :)
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: 1969 LT1 Clone (micks69)
Mick,
So many times I eagerly anticipate the opening of a hood only to be left a bit disappointed. Yours is pure Eye Candy once opened! Nobody will be disappointed.
Chuck
So many times I eagerly anticipate the opening of a hood only to be left a bit disappointed. Yours is pure Eye Candy once opened! Nobody will be disappointed.
Chuck
