Speed pro

[Maddawg]

What is the opinion of the Speed Pro ZH825CP30? I have Silvolite 3241HC that came with my kit , but my motor guy says they are pretty thin and the cheapest out there. Thanks

[Mgardiner1]

I have the H802 (same as the H825's except the 825 uses "standard" rings and the 802's use "metric" rings)

I LOVE the H802's. They have been withstanding some decent abuse in my engine so far. No knocking on start up thanks to them being hypereutectic pistons (allows for tighter bore tollerances). Oletshot was able to dish them to 20cc's for me too. I'd use them again in another build

[lafrad]

I have a set of the H802CP's sitting at home next to my build, waiting for me to send them out to get dish. Machining and tolerances look great on them! the 825's are... the same piston just different ring sizes... I think. Should be a good part!

[Bodo]

I've got a set of the 802's here also. I need to get them dished. Just waiting for the shop to bore the block then I'm off and running.

The price was right. I got an amazing deal on them. I think I'll be spending more on the moly rings than I did on the pistons

[eastin82]

whats the most the 802 can be dished

[gradon]

oleshot will know. pm him

[Maddawg]

Well I picked up the 825's from Summit & machine shot will bore my block Mon so I can get it back & check deck height. eastin82 did you get an answer to how much you can dish your pistons?

[SilverXJ]

I would go with the Speed Pros. I haven't heard anything good about the Silvolites and my machine shop doesn't care for them.

[SilverXJ]

No knocking on start up thanks to them being hypereutectic pistons (allows for tighter bore tollerances).

The knocking with forged pistons isn't that bad. In my build if you weren't listening for it you wouldn't notice. Its just like the engine is a bit louder on a cold start. I usually remote start my XJ 3 minutes before I leave the apartment in the morning and it is ready to roll by the time I am strapped in. This is in warmer weather though and I don't know how it will change when it gets cold again.

[lafrad]

I have a set of forged pistons in my charger, and every time the temp goes below 50 F... geeeze! Can of marbles! Timing an d fuel are good, no knock... can only be the pistons. I know several other smallblock guys in the area that have that same issue. Just something about the forged pistons and Wisconsin winter.

Glad you have a better experience than that!

[eastin82]

yea i did hear from him was told 20cc on 802 going a dif route thanks to his info 677cp dished to 23cc. cant wait to get some parts in!

[Maddawg]

Lookin for some dish info on this piston Speed pro zh825cp30. I found some stuff at Summit Racing where I bought them Compression Distance (in): 1.592 in. Recessed piston design is 0.116 inch deep. , but nothing on pin height. I get my block back tonight so I want to mock up the motor to see how much I am going to have to shave off the block to get to 87 gas. I have 4cw 258 crank turned .010 with 707 rods. I have same head gasket bratcop has, Victor head gasket, MLS style (Multi-LayerSteel) .038 thickness. Any opinions? Thanks Dale

[Muad'Dib]

Lookin for some dish info on this piston Speed pro zh825cp30. I found some stuff at Summit Racing where I bought them Compression Distance (in): 1.592 in. Recessed piston design is 0.116 inch deep. , but nothing on pin height. I get my block back tonight so I want to mock up the motor to see how much I am going to have to shave off the block to get to 87 gas. I have 4cw 258 crank turned .010 with 707 rods. I have same head gasket bratcop has, Victor head gasket, MLS style (Multi-LayerSteel) .038 thickness. Any opinions? Thanks Dale

The pin height is the compression distance.

[SilverXJ]

The MLS gasket is actually .044" compressed, not .038"

[Maddawg]

ok. Maybe I was a little heavy on the mic. Got block and head back. Wed I'll get crank to measure things up and have block shaved so this weekend the motor will be getting put together. Thanks for the tips.