Anyone used FWD's Venolia's in a 2.5 TIII?

[turbovanman²]

Just checking tonight and either she sent me the wrong ones or thats them, but the dish is the same as the 8 valve pistons-I measured it using capfuls of water, so this gives me around 7:1 compression. I bought the TIII 2.5 pistons as I assumed they would give me the proper 8 or so :1 compression. Do I have a coated set of paperweights as I can't possibly use these in a street engine,

Ok, these are Cliffs pistons-notice the small dish-



And mine-

[Ondonti]

This is why I would only order my venolias from venolia.
You would have given them the deck height, cc's on the head, gasket thickness, stroke etc and you would actually have gotten 8:1 pistons :P
That dish is deeper then the pistons I purposely ordered to be 7.5:1 (then after chamber work it dropped to 7:1) Glad I didnt get 7:1 pistons and then turn them into 6.5:1 paperweights.

Hopefully this will be made right.

[8valves]

Even if it is, my motor is down below 7.5:1, it's one of the things that lets me get away with lots of boost on pump gas.

However in your heavy van (no offense) some more off boost power might be a bonus.

[GLHSKEN]

The TIII will spool early. I would think that is not a bad combo.

[Scottmon]

I'm running them in the 2.5 TIII in my '93 IROC R/T and there is NO lack of torque. A little noisy though.

To be fair, I bought my set 3 years ago, so the Venolias she has in stock may not be the same as what I have. It's been so long I can't remember what the dish in the piston was. I *DO* know the pistons came with the wrong piston rings.

[turbovanman²]

Even if it is, my motor is down below 7.5:1, it's one of the things that lets me get away with lots of boost on pump gas.

However in your heavy van (no offense) some more off boost power might be a bonus.

The TIII will spool early. I would think that is not a bad combo.

Well I am trying to NOT run alot of boost, I would rather have some compression to help the van get around and keep out of boost for a DD, that way, my fuel economy should be alot better. I am calling her this morning and hoping she sent the wrong ones. I believe the compression is like just a shade under 7:1 with the stock 8 valve pistons or these.

[glhs727]

OK, first off dish is NOT the only determination of compression ratio.
Did you measure piston height? Maybe our pistons are just a hair taller from pin to top, and althought we have a bigger dish overall the two pistons may give similar ratios. Plus I do beleive Cliff's were JE's based on the box. I don't know what C.R. FM was shooting for, but we were looking for 7.8-1 with our 2.5 venolia's.
Now the good news is depending on your chamber volume and HG thickness that number can vary slightly both ways. Also you can now use a thinner (and less expensive) Cometic since you have plenty of room in CR to work with.
So don't assume what your CR is. You need to measure ALL the factors, not just dish.
later,
Cindy

Just checking tonight and either she sent me the wrong ones or thats them, but the dish is the same as the 8 valve pistons-I measured it using capfuls of water, so this gives me around 7:1 compression. I bought the TIII 2.5 pistons as I assumed they would give me the proper 8 or so :1 compression. Do I have a coated set of paperweights as I can't possibly use these in a street engine,

Ok, these are Cliffs pistons-notice the small dish-



And mine-

[mcsvt]

Nm... Cindy responded first...

[turbovanman²]

OK, first off dish is NOT the only determination of compression ratio.
Did you measure piston height? Maybe our pistons are just a hair taller from pin to top, and althought we have a bigger dish overall the two pistons may give similar ratios. Plus I do beleive Cliff's were JE's based on the box. I don't know what C.R. FM was shooting for, but we were looking for 7.8-1 with our 2.5 venolia's.
Now the good news is depending on your chamber volume and HG thickness that number can vary slightly both ways. Also you can now use a thinner (and less expensive) Cometic since you have plenty of room in CR to work with.
So don't assume what your CR is. You need to measure ALL the factors, not just dish.
later,
Cindy

Not assuming, trying to get my ducks in a row first, I was doing this then going to call you, and still am,

Just tired of getting wrong parts, the run around, etc so I am making sure everything is ok before I get excited.


Edit, just called, all good, I should get aprox 7.8:1 or higher depending on head gasket thickness, deck etc. Crisis over,

[Speedeuphoria]

mill the deck and head a little to clean/flatten the surface and you'll be good(just make sure they surface it w/ the right finish)

[turbovanman²]

mill the deck and head a little to clean/flatten the surface and you'll be good(just make sure they surface it w/ the right finish)

Yep, there both getting milled and using the thinnest cometic.

Whats the surface RA again?

[Ondonti]

how much can you deck the block + thin cometic until you hit minimum clearance?

[turbovanman²]

how much can you deck the block + thin cometic until you hit minimum clearance?

Not sure, TIII's don't have much lift, around .350" but I am just going to clean up the head surface and deck the block, run the thinnest cometic and be done with it. I bet after doing all that, I should be around 8, 8:1 or so which is fine. When I had ordered pistons from Wiseco I wanted 8.5:1 but hey, I have pistons now so I am so happy I could pee.

[Ondonti]

i was thinking about the piston to head clearances when you are decking the block.

[turbovanman²]

i was thinking about the piston to head clearances when you are decking the block.

Gotcha, guess I'll find it when I put her together. I usually only have them take enough off the deck to square it up.

[Ondonti]

Just thinking that if you got a cometic that was thinner then stock plus a lot of decking you would get yourself in trouble without milling the top of the pistons.

[turbovanman²]

Just thinking that if you got a cometic that was thinner then stock plus a lot of decking you would get yourself in trouble without milling the top of the pistons.

True, true. I am going to check that of course.

[8valves]

Yep, there both getting milled and using the thinnest cometic.

Whats the surface RA again?

If using a Cometic, recommended RA of 50 or below. Just ask your shop to give it the best finish possible.

HKS head gaskets for the import crowd ask for a 20 or better!

[Speedeuphoria]

some shops will not know what the heck your talking about when you throw out RA, it they do work on motors that use mls gaskets then they should know.

[turbovanman²]

Well, an update. With a milled block, they are at zero deck. The head was milled-not sure how much as its been worked on before and the thinnest Cometic, cams dialed in, it has 150 psi of cranking compression, yay!!!