2.5 na converted to Turbo II keeps melting #3 piston

[Aries_Turbo]

yeah after i posted i thought of the shim to lower the CR but i figured id wait till i saw what ecm he was running. is that ecm for a 2.2 or a 2.5? you need an egt gauge. you might just be a little hotter in #3 than the rest of the cyl's but its enough over the edge to melt down #3. if i were you, id do what russ said, get the g head, a copper shim, 2.2 turbo pistons and a dual egt gauge with a probe in #4 AND #3 to keep an eye on it. eventually you are going to have to get custom rods or switch to another block/crank/rod setup to keep the motor together as the LW rods arent the strongest. sounds like a cool car though.

Brian

[TurboShadowES]

why not just swap in a turbo block? they arent hard to comby around here, dont know about were you are located thou, even if it had the LW rods it would be better...

[gilpatt]

Well I guess my question now is what would you do or what will it take to make this block work with this setup do I need to change rods pistons crank? What parts do I need to change?

[gilpatt]

Also I really don't what type pistons are in it I assumed they were for a turbo but the machine shop might have gave me NA ones I know they are dished which made me assume they were for a turbo

[minimopar]

If you post a pic of the dish, we should be able to tell. You want the big dish '86+ T1 pistons (or T2 pistons).

[gilpatt]

OK so you guy's are saying it should work if I put turbo pistons in it and the crank, rods and block should work. Is there any difference between 2.2 turbo pistons and 2.5 turbo?
I'm also wondering if the rods will need to be changed to turbo rods from a 2.2 turbo

[gilpatt]

Alright I have made a decission I am keeping my long block after reading many articles from some of your suggestions I think the problem is that it has 2.5 na pistons in it. So I am going to do the foloowing things Intercooler, less boost maybe, (i really love blowing off camaros and mustangs with the Woody convertable) shim the head, install 1986 T1 Pistons (forged) Thanks for all your help

[Turbodave]

Quote:

Originally Posted by gilpatt OK so you guy's are saying it should work if I put turbo pistons in it and the crank, rods and block should work. Is there any difference between 2.2 turbo pistons and 2.5 turbo? I'm also wondering if the rods will need to be changed to turbo rods from a 2.2 turbo

The weak link in your system is really the rods. The pre-common block 2.5's like yours used longer rods than a 2.2 or newer 2.5 so swapping in the beefier rods from one of them wouldn't be an option. Custom rods could be made but that gets pretty pricey.

If it was me I'd take my chances on the stock rods and see what happens, if one lets go it will probably take out the block too, and then it's time to decide on something different. But, depending on luck and how you treat it, it could run forever on the factory rods.

[gilpatt]

I took my pistons in to shop and they were 2,2 turbo pistons So I ordered new sealed power pistons and new rod bearings number three had melted as I thought and 2 others had broken ring grooves The block and everything else looked fine Now I have a question is the 88 na 2,5 head a g type head?

No. On the far right of the head are some numbers, 287 is a G head (I think there were some that ended in something like 445 also, check www.thedodgegarage.com to confirm that). Your engine should have come with a swirl head, it'll have 782 on it.
Good luck.

[gilpatt]

Your right it is a 782 so I went and looked through my bone pile and I don't have a good G type head so I am going to have to use the 782 with a engine saver shim Thanks for the info

[gilpatt]

OK
I'm getting close to finishing up the motor and I plan on doing a compression check after break in to see if I am getting to much compression so what psi is to high with a intercooler and without?