Deck plate for closed deck block, options?
04-16-2013, 03:22 PM
#16
Race Car
Care to elaborate on the studs and possibly a link to where they can be purchased?
While I agree that the 3.0 block is a LOT stronger, I think that s 2.5 with a deck plate should be as equally strong if not stronger. I plan on testing this out pretty soon with my 2.5 based 3.0.
The deck plate we are using is 1/2" thick (minus decking) and mates up directly to the sleeves at the top.
I'm hoping that we are correct going this route and can really crank it up.
I don't personally know if the same problems arise with the 3.0 block.
I would be curious, as my engine after this will be a BIG bore 3+L. If this current setup works out like I want, the 3.0 block will be closed deck as well.
While I agree that the 3.0 block is a LOT stronger, I think that s 2.5 with a deck plate should be as equally strong if not stronger. I plan on testing this out pretty soon with my 2.5 based 3.0.
The deck plate we are using is 1/2" thick (minus decking) and mates up directly to the sleeves at the top.
I'm hoping that we are correct going this route and can really crank it up.
I don't personally know if the same problems arise with the 3.0 block.
I would be curious, as my engine after this will be a BIG bore 3+L. If this current setup works out like I want, the 3.0 block will be closed deck as well.
04-18-2013, 09:57 PM
#18
Rennlist Member
Oh my.... taxing my memory.... and my manila folder 'memory' is in the shop...
I was trying to improve the head seal on the 951 when lots of folks were having problems. This primary issue, I found, was tuning. There's much better tuning today, which has helped the problem immensely.
The 951 is still faced with trying to seal a cylinder (and for some a BIG cylinder) with only four studs. It's a challenge, but the best you can do is provide a conservative tune (lotsa fuel, ez on the spark advance), a good head gasket (I worked with Cometic to improve the 944 gasket) and good cylinder head clamp for those times when there's a bit of detonation due to cooling issues or bad air, or a tuneup that's not 100%.
Since I didn't want to re-invent the wheel, I spoke with both suppliers of 'performance aftermarket' 944 head studs. I asked about material, torque, thread pitch, stretch, clamping force, and cylinder deformation. Neither supplier could answer my questions satisfactorily which suggested they were marketing hardware that could be sub-standard relative to the factory studs. I wanted something I knew was better!
I went to a F1 fastener manufacturer in the UK and had some studs made to my spec for testing. Long story short, I was able to increase clamping force by around 50% (have to re-visit my notes), and without any distortion to the cylinders. All good, except the price. They're rather expensive, but effective.
I made some, and THINK I have two sets left. (You do know that there's 4 different stud lengths for the various 944's, right?) IIRC, one set is 2.5L (long), and the other is for a S2/968.
That's the story.
I was trying to improve the head seal on the 951 when lots of folks were having problems. This primary issue, I found, was tuning. There's much better tuning today, which has helped the problem immensely.
The 951 is still faced with trying to seal a cylinder (and for some a BIG cylinder) with only four studs. It's a challenge, but the best you can do is provide a conservative tune (lotsa fuel, ez on the spark advance), a good head gasket (I worked with Cometic to improve the 944 gasket) and good cylinder head clamp for those times when there's a bit of detonation due to cooling issues or bad air, or a tuneup that's not 100%.
Since I didn't want to re-invent the wheel, I spoke with both suppliers of 'performance aftermarket' 944 head studs. I asked about material, torque, thread pitch, stretch, clamping force, and cylinder deformation. Neither supplier could answer my questions satisfactorily which suggested they were marketing hardware that could be sub-standard relative to the factory studs. I wanted something I knew was better!
I went to a F1 fastener manufacturer in the UK and had some studs made to my spec for testing. Long story short, I was able to increase clamping force by around 50% (have to re-visit my notes), and without any distortion to the cylinders. All good, except the price. They're rather expensive, but effective.
I made some, and THINK I have two sets left. (You do know that there's 4 different stud lengths for the various 944's, right?) IIRC, one set is 2.5L (long), and the other is for a S2/968.
That's the story.
04-19-2013, 12:02 AM
#19
Rennlist Member
Michael, that’s interesting re the headstuds. Are these ones you’re referring to the same diameter as stock or thicker? There seems to be a bit of varying opinion as to how much clamping force can be applied. Assuming that eventually the threads would start to fail and pull out of the block?
We are running 9/16”s headstuds with the deckplate and will monitor headgasket issues of course. In reference to the amount of timing, surely that would be dependent on the fuel type too? Do you have experience with E85?
We are running 9/16”s headstuds with the deckplate and will monitor headgasket issues of course. In reference to the amount of timing, surely that would be dependent on the fuel type too? Do you have experience with E85?
04-19-2013, 09:19 AM
#21
Rennlist Member
Michael, that’s interesting re the headstuds. Are these ones you’re referring to the same diameter as stock or thicker? There seems to be a bit of varying opinion as to how much clamping force can be applied. Assuming that eventually the threads would start to fail and pull out of the block?
We are running 9/16”s headstuds with the deckplate and will monitor headgasket issues of course. In reference to the amount of timing, surely that would be dependent on the fuel type too? Do you have experience with E85?
We are running 9/16”s headstuds with the deckplate and will monitor headgasket issues of course. In reference to the amount of timing, surely that would be dependent on the fuel type too? Do you have experience with E85?
I don't have experience with E85, but if I were building a turbo engine today, I'd be using it!
