Lowering compression,good setup?

[pokertramp]

I remember hearing that you can no longer get the OEM head gasket for the 200ci engine and that the after-market ones are thicker resulting in lowering compression. How much lower is it? I was planning on putting in JE dished forged pistons but I don't want the compression to be too low. I was hoping maby around 8:1 and don't want it too much higher as I am planning a turbo set-up. Also, would the 1.6 rockers be a good choice with this setup? I am also planning on a mild street/strip cam and a 2v carb addition, fuel and ignition upgrade. I am using the stock crank and stock rods. Am I on the right track? I never owned a ford so bare with me any input would be helpful.

 

[grocery getter]

Hello, Do yourself a favor and get the fordsix performance book. (good reading)
checkout this link: http://falconperformance.sundog.net/compcalculator.asp

you can get the book there as well as the fordsix shop it's linked on the home page here. they are or will be offering head gaskets perfect for the turbo.
remember the combustion chamber size also has to be checked.

checkout this thread:http://fordsix.com/forum/viewtopic.php?t=47668

 

[CZLN6]

Howdy Pokertramp:

On a stock '67 200 with a CR of 9:1, simply replacing the stock OEM steel shim head gasket for an aftermarket gasket of .050" will result in a CR drop of .5 or 8.5:1.

AKT cylinder head chamber volume increased in heads after the eary '70. earlier were at 52 ccs, later were at 62 ccs. What year engine? what is the casting code for the head you're working on?

The 1.6:1 rockers would be a good choice with a stock cam. But, if your going to a performance cam compatible with a turbo, the higher lift rockers are unnecessary and add to vavle train stress. Get the extra lift you want in the cam lobes.

Hope that helps you.

Adios, David

 

[pokertramp]

Howdy Pokertramp:

On a stock '67 200 with a CR of 9:1, simply replacing the stock OEM steel shim head gasket for an aftermarket gasket of .050" will result in a CR drop of .5 or 8.5:1.

AKT cylinder head chamber volume increased in heads after the eary '70. earlier were at 52 ccs, later were at 62 ccs. What year engine? what is the casting code for the head you're working on?

The 1.6:1 rockers would be a good choice with a stock cam. But, if your going to a performance cam compatible with a turbo, the higher lift rockers are unnecessary and add to vavle train stress. Get the extra lift you want in the cam lobes.

Hope that helps you.

Adios, David

Well the motor that is in there now is a 66 mustang, I plan on getting one from the junkyard and build that one up, then I will use the turbo setup on the motor in there now, mostly to test and tune and for fun and if it craps out, I have a backup to drop right in and this way I know the limits to an extent of the turbo. It seems like with the dished pistons, .050" head gasket, and bigger chambers on a newer motor will put me below 8:1 or right at it. Low is good, more boost.

As the other person mentioned about the book, a friend of mine has that book and I am just waiting for her to find it.

 

[grocery getter]

Less compression, More lag.....

 

[falcon fanatic]

Less compression, More lag.....

Oh, oh, this sounds like a philospohical question: high compression/low boost vs. low compression/high boost. Which is better? Having driven many turbo cars, some of which where totally gutless off boost, I'd go for the high compression/low boost myself. But I've never actually built a turbo engine, so I'll let the experts debate this.

 

[Marine05]

Well its basically whether you want quick launches, or faster straight aways. High comp/ low boost is best for launches since your turbo only kicks in after a certain rpm. Now if you want long fast speed, Go the other route with low comp/ and high boost. This gives u the extra boost in the long straight pushing more horses and faster speed times. But dont over boost too much or u can start snapping wrist pins and the whole nine yeards.

 

[pokertramp]

Well its basically whether you want quick launches, or faster straight aways. High comp/ low boost is best for launches since your turbo only kicks in after a certain rpm. Now if you want long fast speed, Go the other route with low comp/ and high boost. This gives u the extra boost in the long straight pushing more horses and faster speed times. But don't over boost too much or u can start snapping wrist pins and the whole nine yards.

Thats what I am afraid of, I know I don't want to over boost but I don't want to kill the motor either. I figure with about 8:1 or 8.5:1 I would be safe. For the street I plan on running no more than 10psi on pump gas. When I take it to N.E. dragway, I will probably run about 15psi on high octane. I think that would be within reason, right?

 

[addo]

I don't think a 50% increase in boost pressure is so simple as adjusting wastegate or similar, if you want the motor to be functionally "useful" under either condition. Without anything like VVT, you are going to be compromising one setup for the other.

Ford sixes under heavy boost usually fail by piston damage - either it punches a hole in the top, or busts the ring lands. That's ignoring the usual head gasket failures...

It's far less exciting, but try to focus on your fuel and ignition control first. Once these are 100% tunable and you have a good feel for how they respond to varying conditions, then is the time to start with another direction for your motor.

 

[rocklord]

I had a 2001 Volvo S60 with a 2.4L engine and a low boost turbo. The turbo was small so it spooled up early to supply low rpm torque. If you want low end torque, use a small turbo and restrict the maximum boost.

Either way you go, it would be best to install a knock sensor/advance retard unit, and a boost blow-off valve

 

[pokertramp]

I was thinking of getting good pistons and have them coated along with anything else I can to protect the engine. I remember reading on a 300zxTT and the whole engine was pretty much bullet proof. It may cost a lot to do it but it's done right. I have read so much on fuel and ignition upgrades my head hurts and I have about 30 different bookmarks. I plan on buying a 2v blow thru carb, think it was about $700 or if and when I am ready and the new intake is out for the classic inline head I might go that route and get a stand alone TBI setup. I am still doing research and if it takes me another year, so be it, I want it done right.