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An L46 in three steps.

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Old 12-02-2017, 05:22 PM
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DorianC3
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Default An L46 in three steps.

Greetz all,

I have a 1969 L46 Corvette with a non-descript 350. It’s a 350 with 882 heads, an unknown cam, full headers, a 750 Performer carb, and a first Gen Torker intake. The low to mid rpm is kinda weak.

I’m looking to install L46 or better performance. To this end, I have a numbers matching 4-bolt block in my garage.

My plan is to replicate an L46 with a Q-jet carb and my 4-bolt block with aluminum heads and a non-roller hydraulic cam Sort of an homage.

I’d like to move forward in three steps as $$$ comes available.

1. Scrap my intake for a modern one that fits under my hood with a Q-jet

2. Replace my 882 heads with 195cc small chamber heads and a good cam.

3. Rebuild my 350 0010 block into a 383 with a good street cam (not hydraulic roller) and the above heads and intake.

What, Gentlemen, would be a good combination to rival and improve upon an L46 with modern aftermarket?

What should I select as intake, heads and cam (both 350 and 383) ?

MTIA,

D.
Old 12-02-2017, 09:24 PM
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NeverTooOld
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An Edelbrock Performer intake #2101 is a good start.
Old 12-02-2017, 10:49 PM
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Boswell
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A true L46 will have forged internals including 1182 gm crankshaft. The main caps on the blocks were (2482) nodular iron. A 3.48" stroke 350 and all had 2.02 valve 186 or 041 closed chamber heads. Pistons were forged "pop up" at 11:1 compression. A cast iron intake and it's own hydraulic flat tapped camshaft.
Not to start an argument but I don't know how much of this you change before you no longer have a true L46.
Old 12-03-2017, 02:20 AM
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DorianC3
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Apologies, I was not very clear. I’m not after a true L46.

I would like to use my 0010 4-bolt block as an homage more than anything else. (That and it has never been rebuilt, and after zzz in my basement for over 15 year, it deserves to be) I’m after matching or improving upon the L46’s performance with modern technology but also preserving the original look and configuration. No fuel injection, forced induction, Holley carb, roller cam, or what not. That large headed HEI will have to go as well.

I plan to add some cubes to bump it up to 383; use aftermarket aluminum heads (painted orange) and aluminum intake (GM orange as well) with a spread bore for a Q-jet, and a good hydraulic, non-roller cam.

Scalable is a key word too. That is, I want to buy an intake and a Q-jet in a month or three from now. I think my vintage, first generation Torker, as cool as it is, is dismal for street use. I do realize the unknown cam might also be playing a role in the poor performance.

Then a few months later I plan to replace my 882 heads with probably Blueprint 195cc aluminum heads + a matching cam.

Then, some months after that, keeping heads/intake/carb, I plan to rebuild my 350 short block into a 383 with a more appropriate cam.

So I'm looking for a recommendations and opinions on intake, heads and 2 cams... that would propel the 1969 ‘vette into L46-like-performance-or-better territory.

The intake will likely be from Edelbrock, and I agree with NeverTooOld, the Performer 2101 seems to make the most sense in terms of performance matching the original L-46, accepting a Q-jet, and clearing the hood. I cannot imagine it isn’t an improvement upon the original GM L46 intake.

I like the price/quality combo of Blueprint’s aluminum heads.

Cam for the above for a 350 and another for a 383 generating decent vacuum and for street use: I’m absolutely clueless!

As the short block internals, the rotating assembly, I’ll be shopping around - possibly Ohio Crankshaft.

Last edited by DorianC3; 12-03-2017 at 02:38 AM.
Old 12-03-2017, 09:34 AM
  #5  
Rescue Rogers
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For the heads , look at the volume, you'll want something close to 64cc to keep the compression up, plus higher compression pistons and new connecting rods. brands like AFR, Dart, World Products are all going to be similar except for price. The big expence is when you get into CNC porting. I believe on a street engine "as cast" heads are fine and will save a lot of money. You can get a great deal from Hekemian Racing Engines on as cast heads. $785 for a complete set that will be perfect for you. You can find him on the Boston craigslist under sbc heads https://boston.craigslist.org/bmw/pt...396434187.html or his website. I just bought a set for future use and they arae awesome looking and well made. Hopefully I can drop hem in after I get my motor broken in. Call him up with all your specs on your new cam and he will set up the springs for you. Just tell him what knowledge you do have because he is an Engineer and they sometimes think everyone is as smart as they are, which I am not and I get left in the conversational dust quickly.

I also like to go to a sight like Summit and making a wish list to get an idea of pricing. You'll also realize what else will need to be changed like rocker arms because most aluminum heads have bigger springs (wider, usually 1.54" vs 1.25"stock) for bigger cams with more available lift, then of course you'll have to buy valve checking springs and a pushrod length tool to check your pushrods contact points. And while your in there you may as well buy all new bearings and a new oil pump. If its a manual then why not replace the all the clutch components. Since your going to a higher compression engine then maybe look at a new starter if the old one doesnt have the torque or is worn out. Dont forget all the gaskets.

Seriously though, new heads may need new pushrods, new gaskets which probably dont come as a set so read the quantity line, and of course do not get your block decked if you want to keep it numbers matching. It doesnt sound like your going to be a racer, just a cool guy on main st with maybe a few burnouts and a couple of zero to 60 runs for the seat of the pants rush (on the high way of course). Thats what I do atleast so you probably dont need that or line honing the block or any of that high horsepower racer stuff. I would get your cylinders checked before buying pistons so you know if it needs a light honing or boring out.
Good luck, keep us posted

Last edited by Rescue Rogers; 12-03-2017 at 09:39 AM.
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Old 12-03-2017, 02:51 PM
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DorianC3
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Outstanding feedback and contact.

Yes, as you put it, I am only looking for tha “SOP rush” and nothing more.

I’ll keep y’all posted on the build when the time comes. But I’m not looking for real high performance.
Old 12-03-2017, 06:37 PM
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Default Non-Roller?

You mentioned not wanting to use a roller cam. Do you mean solid or Hyd? If you want to take advantage of good flowing heads, you will need more cam. No one can see or hear it. This does cost more but when you are replacing the valve train, it is not so much.
At a similar duration, a Hyd rol should have 30 hp more w/quality heads.
If you want SOP, this will help.

JMHO

R
Old 12-04-2017, 07:15 AM
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DorianC3
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Originally Posted by Taijutsu
You mentioned not wanting to use a roller cam. Do you mean solid or Hyd? If you want to take advantage of good flowing heads, you will need more cam. No one can see or hear it. This does cost more but when you are replacing the valve train, it is not so much.
At a similar duration, a Hyd rol should have 30 hp more w/quality heads.
If you want SOP, this will help.

JMHO

R
And there you make and excellent point !!!!! If I do that conversion then the valve springs will need to be changed to accommodate. But, yeah. That does make absolute, convincing sense.

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