340 Winter Upgrade

[Shane Kelley]

While my final plan is to build a stroker 416 for the car. My curiosity got the best of me on how much rwhp I can get out of my little stock stroke 340. I have a pretty good baseline of 351 before this upgrade. That's pretty good numbers IMO. So I pulled the intake & heads to send to Bruce Toth for some serious port work. This will be the mods as of now so I can measure what the gains are. I was going to switch intakes and go with a Super Victor open plane but that would have changed a big variable for comparisons. After checking hood to air cleaner clearances the 1" taller intake was not going to clear and I really want to stay with the factory one. I just like the looks of it.

I did see where a couple valves slightly tagged a piston. Going to dress the pistons up and check valve spring pressures and probably change them. They are my prime suspects for that issue. I haven't missed any high rpm gears so I know that's not the case. But I did do one last big top end run before I parked it. I'm thinking that's when it happened. It was turning 6800-6900 rpm in top gear at 135 mph. Pretty long run and I was waiting for the motor to pop any second.

[blown motor]

I look forward to seeing the results. I've been thinking of doing some port work on my heads.

What pistons are those? Mine have double valve reliefs.

[Shane Kelley]

I look forward to seeing the results. I've been thinking of doing some port work on my heads.

What pistons are those? Mine have double valve reliefs.

I don't know what pistons are or if they are even forged. This was a good used motor I took in for some money owed me. It looked like a recent build when I inspected the bearings and cylinders. 71 motor out of a Dart "race car" for what ever that means. It did have a Racer Brown solid lifter cam in it and a set of ported small valve J heads on it and topped off with a big MP open plenum intake. When i got my Cuda the numbers motor was tired and starting to rattle at the top of each gear. So I threw the Eddy top end on this motor and stuck in the car just so I could keep driving it and not blow the #'s motor. After swapping out some different cams the motor ran so good I just decided to put it back in after restoration.

[Jim AAR]

I like the light bar you have under your hood, great idea. Sure beats a trouble light.

Did you make it or buy it?

[Shane Kelley]

I like the light bar you have under your hood, great idea. Sure beats a trouble light.

Did you make it or buy it?

It's just a LED shop light from Menards. Light weight piece. I use it working in the car and under the car. Works 100 times better than any drop light. Doesn't matter how many lights you have in our shop. You pop that hood and it creates a shadow and you can't see worth a damn.

[cudabob496]

135 in a Cuda?
Surprised the front end didn't lift off the ground.
I built a front end spoiler and splitter, and the car
nose just plants itself on the ground at high speed.
Plus, gives better cooling through radiator, and reduces
turbulence under car, so you are faster.

[cudabob496]

What are those tire lifts/supports???

[Shane Kelley]

135 in a Cuda?
Surprised the front end didn't lift off the ground.
I built a front end spoiler and splitter, and the car
nose just plants itself on the ground at high speed.
Plus, gives better cooling through radiator, and reduces
turbulence under car, so you are faster.

I got all that covered. This car hugs the ground and is very stable at high speeds. Corners and stops great also. 
Yes stock suspension is a little hairy at high speeds. That is the main reason I did all the upgrades.

The black boxes that the car is sitting on are made by Race Ramps and super light weight.  Got them from Summit Racing.

[cudabob496]

Cool! Awesome car!

[734406PK]

Quote: I did see where a couple valves slightly tagged a piston.

Check your piston to valve clearance as well. The carbon deposits on the cylinder head combustion chambers and pistons looks a little dark, she may be running a little rich.  Beautiful 'Cuda BTW!!

[ToxicWolf]

The pictures are great.  Thank you!

[Shane Kelley]

Quote: I did see where a couple valves slightly tagged a piston.

Check your piston to valve clearance as well. The carbon deposits on the cylinder head combustion chambers and pistons looks a little dark, she may be running a little rich.

I had it jetted a little fat for a while. I have been playing with jetting up and down to see where the most power gains are.  I was lazy and ran these for a month before backing it down. Blew the whole ass of the car out with soot. The type of fuel effects the burn also. Normally my plugs look really nice.

I have already checked that when I installed the cam. There is plenty of valve piston clearance that's why it's not on all of them. I'm pretty sure it's a couple weak springs. I will know for sure once I test them.

[734406PK]

Yes, very possible the P/V contact could be caused by weak valve springs. Other possibilities are loose valve stem to guide clearance, or the valve relief pocket is slightly undersize for the Eddy intake valve. In the pic, it appears that the intake valve is contacting the piston just outside of the valve relief pocket. If this is true, this issue would not be caused by a weak valve spring IMO.

[Brads70]

It's good you found the valve contact before something bad happened. I have those raceramps blocks too as well as the ramps . I like them nice piece , I even drive the family suburban up on them for oil changes. ( I did get the HD versions)

[Cudakiller70]

  Good stuff Shane Thanks for posting