K-car turbos

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CUDAGUY

aka Prince Valiant
Joined
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anyone thought about using two k-car turbos?

The way I think of it.
2.2 + 2.2 is 4.4L really close to the 4.5L that a 273 displaces. A nopo 273 has 8.8:1 compression, with some thick headgaskets should be around 8.4-8.5:1......perfect for a turbo app. These turbos are capable of 17-18 lbs and have a 2.5 outlet that accepts the typical 80's-90's chrysler ball flange.

So heres the plan.
Ive got a 2-barrel 273
I will whip up basic log style manifolds
use two 2.2L K-car turbos
2.5" dual into 3" single with cutouts
some kind of small intercooler
#302 heads, stock, unported, cleaned up a little
stock 340 valvesprings
stock 340/360 cam with hyd. valvetrain
thicker headgaskets
performer intake
stock replacement electronic ignition
1405 edelbrock carb
no more than 10 pounds of boost

concerns
using an edelbrock carb in a blow through application
strength of stock 273 cast pistons
what range spark plugs to use

any thoughts or suggestions?

Thanks,
Jared
 
When running a blow through system, the general rule is the carb has to be mechanical secondaries
 
Normally with blow through systems the carb goes inside a sealed box so the entire carb is at boost pressure then it doesn't make a difference if it's a mechanical or vacuum secondary.
 
Edelbrock carbs are mechanical secondary.
 
Most blow through setups I've seen don't use a box, but they do use a Holley. Carter, and Edelbrocks, are a little harder to configure, but not impossible. I've seen a tutorial on how to do it, pretty sure the biggest hurdle was finding solid floats (you can crush the brass ones with too much pressure). I think they soldered/riveted solid Thermoquad floats to the end of the arms. If you're serious about doing a Carter, I can try and find the instructions.
 
BTW, try and find the Garret turbos, 87 and earlier non-intercooled or any intercooled motor. The Mitsu turbo has a much smaller scroll and will choke your motor, even though both the Garret and Mitsu have the same turbine A/R.
 
wow, lots of fast responses!

even tho this plan is not set in stone and I do have a 4160 holley I could use, whats the potential of filling the floats in the eddy with something?

my main concern is the strength of the pistons.....
 
And I happen to have a Garret turbo sitting in my garage.........
Actually - I have the whole d#(M long block. Anybody in SW PA area doing the K-car turbos needing parts????
 
Great Idea! I had it a long time ago...

From what I know the stock pistons are pretty tough... Your main concern will be the compression ratio... but it looks about right. As long as you keep the RPM limited and stay with low boost.

My concerns:

Backpressure: It sounds like you will be really choking it with small pipes.... you might consider dual 3" into a 4-4.5" pipe... Because turbos HATE exhaust restriction.

Ignition: You might consider upgrading the ignition with a multispark setup. boosted charges are a lot harder to ignite cleanly then a regular one.

Other than that it looks good!
 
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