My new stock stroke 400 build

[Orig69]

I had to go in for a procedure this morning, so I had some downtime. I found the dyno results from the first stock stroke 400 I built. I can't believe it was 2005, almost 19 years ago to the day. We'll see how close this build comes to that one. I have stepped down on the cam from 222/234 to 214/224, but most of the rest of the specs are similar. That one had a nice flat torque curve. That was my buddy Tom at the controls.

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Did you do any valve bowl work on the 400 engine from 2005?

 

[qkcuda]

Yes the 452 heads on that engine were pocket ported and flowed about 250/200. I am hoping that the new 346 heads I just did will be close to that.

 

[qkcuda]

Well, finally some progress. Pistons and rods are in, it's starting to resemble an engine.

 

[RemCharger]

We'll, finally some progress. Pistons and rods are in, it's starting to resemble an engine.

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Awesome! So what's the deck height work out to?

 

[Don Frelier]

#6 looks like it's right up there

Probably the same pistons I have in my 383.
They've worked well for me.

 

[qkcuda]

I think they said the deck height was .016, but it looked closer to zero deck than that to my eye. I will have to wait and check the build sheet.

 

[eldubb440]

possibly some sort of metric conversion......

 

[RemCharger]

possibly some sort of metric conversion......

1/4 of a potato chip maybe?

 

[qkcuda]

possibly some sort of metric conversion......

I am too old for my eyes to register in metric

 

[qkcuda]

If we are at .016 then I will be at 8.5:1 compression as opposed to 8.7. No big deal, as that is where I am at now on the 361 and it runs well on regular gas.

 

[RemCharger]

If we are at .016 then I will be at 8.5:1 compression as opposed to 8.7. No big deal, as that is where I am at now on the 361 and it runs well on regular gas.

You've measured the chambers/ know the headgasket(.040?) Etc? Seems low

 

[1967coronet]

I decided to rebuild my 625 AFB, so that I could compare it to the 625 Street Demon on the dyno. Word of advice, I bought an Amazon rebuild kit. The new seats would not screw into the carb body, the thread seemed different, the needles were okay. The floats were pretty thin material so I didn't use them, and several of the gaskets had to be trimmed a bit.

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Just a heads up, the blue accelerator pump rubbers do not last very long in 10% ethanol fuel.
The red edelbrock ones seem to hold up best.
Was not sure of what you have available for fuel.
Great build thread.

 

[Don Frelier]

You've measured the chambers/ know the headgasket(.040?) Etc? Seems low

You'd have to have a very large head volume to be down at 8.5?
I get approximately 92 CC using a .039 gasket to be that low?

 

[qkcuda]

You've measured the chambers/ know the headgasket(.040?) Etc? Seems low

Here is the calculation. The heads cc'd at 89 before we milled them 5 thou, so I assumed they are at 88 now. The valve reliefs are huge in these pistons. That and the short stroke leads to the low compression. This is meant to be a high torque cruiser that will run on regular gas, however, my back up plan was to build a solid short block as close to zero deck as possible, so that with just an aluminum head and cam swap the engine could make considerably more power. I had calculated that we needed to mill the block around 25 thou. When they measured it they only ended up taking off somewhere between 10 and 15 thou, so obviously their calculations were off a bit.

 

[qkcuda]

Just a heads up, the blue accelerator pump rubbers do not last very long in 10% ethanol fuel.
The red edelbrock ones seem to hold up best.
Was not sure of what you have available for fuel.
Great build thread.

The rebuild kit I bought off Amazon said it was compatible with alcohol, but a lot of the parts in the kit were poor quality, so who knows. The plan is to run the Street Demon, but I wanted to test the AFB while it was on the dyno to see if there was any difference. They are both rated at 625 CFM.

 

[Don Frelier]

Here is the calculation. The heads cc'd at 89 before we milled them 5 thou, so I assumed they are at 88 now. The valve reliefs are huge in these pistons. That and the short stroke leads to the low compression. This is meant to be a high torque cruiser that will run on regular gas, however, my back up plan was to build a solid short block as close to zero deck as possible, so that with just an aluminum head and cam swap the engine could make considerably more power. I had calculated that we needed to mill the block around 25 thou. When they measured it the only ended up taking off somewhere between 10 and 15 thou, so obviously their calculations were off a bit.

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The pocket volume on the pistons is a killer.
I'd seriously consider a steel shim gasket.

 

[qkcuda]

I'm good with the compression Don. Currently I am more worried about being able to run regular gas in this engine than squeezing out every last horsepower. Here in Canada the extra cost for mid grade or premium fuel ranges from 25 to 35 cents a liter. That is an extra $1.00 to $1.40 per US gallon.

 

[Don Frelier]

I'm good with the compression Don. Currently I am more worried about being able to run regular gas in this engine than squeezing out every last horsepower. Here in Canada the extra cost for mid grade or premium fuel ranges from 25 to 35 cents a liter. That is an extra $1.00 to $1.40 per US gallon.

Your cam selection should help with the lower ratio.


I wonder if it will keep up with mine on the highway?

 

[qkcuda]

Is that a challenge, Don? Loser buys the beer?

 

[eldubb440]