2276 Draw through 'glass buggy. It's finally happening!

[Chip Birks]

Update...
The motor is out of the buggy, and up on the work bench.
As found, the deck height is a meager .020", It had a .060 copper head gasket and a 55 cc combustion chamber giving a compression ratio of 9.2 : 1.... not great for a turbo.

In my. Ind, a fresh set of Berg dished pistons and no head gasket could net me a cr of 7.7-8:1.

Am I on the right track? Does that seem like a reasonable approach?

So previously, your actual deck height, after shims, was at .08? And now you want to remove the .06 shims and put in a piston with a dish? That means the outside edges of the piston will now be .02 from the head, right? That is at least .02 too tight. You could run a .04 head gasket and dished pistons, or adjust the shims at the base of the cylinders to get things closer to .04 in the combustion chamber, but you have to have at least that clearance.
Your main problem is the chamber size, to get turbo compression out of a 2276 you need almost 70cc in the head. Your 55cc heads just require lots of deck height, or piston mods and deck hight to get what you want. Personally, I wouldn't set compression at 7.anything, but that's just me. I'd rather the engine be fun to drive even while off boost.
What cam is in the engine?

[slayer61]

Thanks for your input, Chip. The cam is an Engle W125

[slayer61]

Yes sir. I understand my deck height needs to be fixed. Are you saying that I shouldn't be concerned about dished pistons assuming all other things are within spec? For the record, I was hoping for a static compression of 8:1

Thanks again for your input

[Chip Birks]

I'd probably just run a big deck before spending the money on dished pistons. But that's just me. A lot depends on what you are planning to do with the car. Something that is gonna get driven a lot may want to put a little more effort into getting a tight and efficient deck height. If it's a weekend warrior, I'd set the deck whereever you need to get the compression where you want it and then just enjoy beating on it.
What fuel do you plan to use? I had a turbo car with compression around 9.4:1 and it was a blast to drive. Your w125 won't hate the compression, it'll probably be awesome to drive on and off boost. Have you put miles on it at 9.2:1 and have complaints?

[slayer61]

Hi Chip. I love the buggy. It's never been much fun on the freeway, but it's a hoot to drive otherwise. I have no complaints. I am just addicted to horsepower and can't leave well enough alone. As said by a friend and mentor "I've never met a horsepower I didn't like".

Keep the compression as it is & limit boost? The rotating assembly was purchased with boost in mind. 4340 crank, H beam rods, etc

[Chip Birks]

Keep the compression, run e85 and turn up the boost! That's my vote!

[slayer61]

Keep the compression, run e85 and turn up the boost! That's my vote!

Not today Chip... pump gas for now.

Y'all have convinced me. An assortment of barrel spacers and copper head gaskets have been ordered from CB Performance.

Stay tuned.

[slayer61]

Update

Between .120" of barrel shims and a .040" head gasket, I got my compression down to 8.5:1 static. I did valve train geometry this morning and I'm happy with the results. Cut-to-length push rods are supposed to be here tomorrow, then rockers can go back on, and the motor closed back up. PROGRESS!

[slayer61]

It's slowly coming together. Reinstall the motor and then all the time consuming details.

[slayer61]

So the motors in. Fuel and oil lines are done,for now. I still need to change out the fuel pump, wire the motor and the boost controller and run the boost signal lines to the waste gate and etc.

[slayer61]

I experienced a "semi-successful" start up. Just a couple of "minor" issues.

1). My 2" 45 degree silicone hose collapses when under vacuum... dammit

2). It's leaking oil like the Exxon Valdez. First thought was a leaking push rod tube seal, but I think I'm gonna find it's the dog house cooler or seals. It's just pouring out double dammit.


But it did start and run!

[slayer61]

So my oil leaks have been reduced to an acceptable level by resetting and spinning the pushrod tubes. But im still running dead lean before it dies all together. I have proven that the idle circuit is clear from the idle jets wells, through the progression holes we'll and to the mixture screws. New idle jets ordered and fingers crossed

[Alexander_Monday]

Good to hear you got the oil leak fixed.

I also learned the hard way about silicone hose collapse.
I normally have a metal tube inside a hose about 8" long that couples 2 other tubes and forgot to put it in one time.
This was for an individual cylinder between the intercooler and head and it looked like one of those medical respitory bags at idle.

[xzener]

You could weld an extension to the T manifold, limiting the amount of silicon needed.

[slayer61]

You could weld an extension to the T manifold, limiting the amount of silicon needed.

Yes Sir, but what I needed was the 45 degree elbow, and I'm not a welder. I opted to cut down the stainless elbow and couple it up with the silicone hose. It seems to work.