tpi 421 vette

Hey Guys, forum member Mike Westhoff (Gears) from Oklahoma contacted me about building a 409 (4.030X4.00) stroker for his 96 LT4. He sent his car to me. We reused the factory 4 bolt main block, but that was about it. We started with a Eagle 4340 crank with the rod journals turned to small journal. Small journal is the way to go on a 4.00" stroke. It helps the rods clear the cam and block much better. I used to use Crower stroker sportsman rods on alot of the engines I do. But those rods have been discontinued. Crower still sells their billet rods, but not their sportsman stroker. With a 4.00 stroke, you need a good stroker designed rod. So I went with the Callies Compstar HD rods. They are a I beam stroker rod. And they cleared real well. They are probably nicer than the Crower sportsman rods (but more money). I also went with SRP forged pistons. I had my machine shop Strasberg Machine do the machine work. They balance to within .5 of a gram. They do really nice work. Mike wanted a drive it anywhere car that wasn't too radical. I went with a Comp 230/236XFI cam. I figured it would have power everywhere from idle to 6000 rpm. And with 409 inches and a 4.00 stroke, it will have alot of torque everywhere. Torquey motors are fun to drive, and you don't have to wind it up to feel the power. I also went with AFR 210 Comp port heads. Those will support alot of power but will be very responsive on a 409. I have done a few 409's, and even AFR 227's are still responsive on a 409. I decided to reuse the LT4 intake. But it would need some work to keep up with the heads. So I had our own Ron Kalthoff (Cuisineartvette) port the intake. He did an amazing job. He got 365cfm out of it. And with this many cubes, you can't port the intake too far. The intake now flows more than the heads. The intake couldn't have turned out any better. Here's some pics of the engine build.






Here's the factory LT4 engine out of the car and on the engine stand.


I cleaned up the engine compartment while the engine was out. It was pretty dirty.


Here's block back from the machine shop.When I was done cleaning it, you could eat off of it!




Eagle 4340 crank, small journal, internal balance.




I degreed the cam, it was 2 degrees retarded and left it there. It will give it a few more hp on the top end, and lose a few on the bottom end. With 409 cubes, I'm not worried about bottom end torque.






It's built to a shortblock.

tpi 421 vette

Here's some pic's of the intake and the engine completely done.






Ron did a great job on the intake. 365 cfm will outflow the heads.

bjankuski

Nice, set-up, should run well.

1963SS

Another great looking engine. Was that the 280XFI cam. That's what I have in my 383 Impala and it works great. Great torque down low with a 383 and a heavy car.

tpi 421 vette

It's the 280XFI cam

383vett

Looks great Jim. Good job as always!

pianoguy

Very sweet!

1985 Corvette

Love those 409s. Guess Matt's 409 club picked up another member! Ron is the man! I always point people in his direction looking to make their engines breathe more.

aboatguy

Looks great!

95wht6spd

Nice, have only seen a few LTx 400+ strokers over the years. Any clearancing issues?
Please post dyno #s when done.

tpi 421 vette

You can see the clearancing done to the block. Using the right connecting rod is key.

89L98TPI

Top notch of course. Great work by Ron also.

Love those Valve covers on top of those heads. Can't wait to get mine together...

rklessdriver

Nice build Jim.

Will

tpi 421 vette

Here's more pic's of it going together.


We used a Spec stage 3 clutch




I am sure some of you guys are familiar with this. I had to have the valve cover notched for the alternator.


I had to wire in a relay for the Mezeire electric water pump

STEVEN13

Me Want!

HlhnEast

Jim, how much invested in parts so far?

Damn sweet looking job!

wfd1739

Man that looks good. What kind of numbers will the hp and torque be?

tpi 421 vette

It really adds up with all the little stuff. Plus there are alot of extra's that go beyond a normal engine job.

tpi 421 vette

I would think it would be at least 525hp at the flywheel, and around 550 ft/lbs torque at the flywheel. Mike is going to chassis dyno it when he gets it back home to Oklahoma. This build wasn't a max effort build. He wanted something mild he could drive everyday. But there are alot of really good parts in it. We left alot on the table not putting more cam in it. But this will do exactly what he wants it to do.

Beach Bum

Great job as always Jim !

Somebody is Oklahoma is going to be a happy camper.