Vertex limits in 2.5 Mercury

[Wayne Arnold]

What is max. safe compression and rpm limits for Vertex pistons. Thought I remember DSRA guys 9500 rpm or so. Will these hold up for 160-180 lbs compression? Just curious to limits people have seen.

[TripleA]

What piston is everyone running in their Pro-Stock motors for DSRA?

[90 5.0]

Prostock motors are 150 psi, most use vertex. They turn over 9500 these days. i have no idea how much more compression than that they could take.

[StratosVT]

They aren't any different than a forged piston when is comes to their ability to withstand compression and rpms.....the issue is if something causes one to seize or some other mechanical or electrical issue surfaces, they will disintegrate whereas a forged piston will hold its form better. Think of forged pistons as insurance...they cost more but can save you $$$ when bad things happen and the higher rpms you plan on turning a motor, the more extreme the damage will be if something bad happens. Prostock motors are usually pretty reliable for drag racing and its rare to see one get destroyed. Keep in mind though that these motors arent running for long distances at 9k rpms.

[Wayne Arnold]

Thanks for your input, I understand. I just thought I had heard of cast failures, stock pistons, with compression and or rpm over 7500 or so. Also understand DSRA prostock over 9000rpm in 1/4. My concern is above 150lb compression at that rpm on Vertex. May not go over 150 but just in case wanted to play around with compression, also only running 660 ft.

[StratosVT]

Thanks for your input, I understand. I just thought I had heard of cast failures, stock pistons, with compression and or rpm over 7500 or so. Also understand DSRA prostock over 9000rpm in 1/4. My concern is above 150lb compression at that rpm on Vertex. May not go over 150 but just in case wanted to play around with compression, also only running 660 ft.

I know of at least 1 DSRA lakeracer boat turning a promax 9600-9700 rpms (1/4 mile) with somewhere around 200lbs compression on the Vertex pistons with no issues. Ran every race last year as far as I know. They're excellent pistons.

[Wayne Arnold]

Info. I was needing. Thanks

[SSTOM]

I have a highly modded 200 that I run Vertex in and running 180 lbs comp and have turned it well over 9000 and for longer than a 1/4also. Then I have a 225 pm with them all stock except 16 amp charging and a recurved ecu and spin it 8000 all the time with 160 lbs comp. It does have hip bearings and good rod bolts in it as well.

[Wayne Arnold]

Good to hear SSTOM. thanks

[90 5.0]

I made an error in my above post. I "thought " pro stock motors ran 150 psi. I was re reading the rules as I am contemplating building a prostock motor and they are 26cc headed motors. That's way over 150 psi.

I mi don't know how much compression that is 180-200????!!??

[TripleA]

26cc heads were about 185lbs of compression on my 260. Not sure what they would be on a 200 though.

[levi ledet]

pro stock motors run 32cc heads they can only run that in pro stock in other classes like super comp a pro stock motor can run 26 cc heads

[90 5.0]

pro stock motors run 32cc heads they can only run that in pro stock in other classes like super comp a pro stock motor can run 26 cc heads

Thats what hat I thought but I swear I just saw 26cc in theb2016 rule book

[TripleA]

I can't keep up with it either but I just double checked rule book, it's 32cc like Levi said.

[90 5.0]

I'm retarded. Super comp rules for a prostock motor allow 26cc heads. But for the op's question. Vertex will live at that compression.