Re: ZZ502 DUD questions
 

The oil pressure loss it not from the lack of oil, that much I do know. It spit out maybe 1/2 a quart. The pressure loss as best as I can tell was from foaming oil. And now apparently temp.
The boat will be at Speedmaster Marine in TO, on monday night, and the motor is going to Active ASAP.
F- it, I am paying to make it right. I also figure I may as well get Active to pump up the motor a little as I am going to get them to go through it.

RT

Re: ZZ502 DUD questions
 

Suggestion: If you want to add some ponies without breaking the bank, spend it on the cam/heads. See Chris Straub for details. I choose to use the GM/Edlebrock oval port heads and have them ported. See pic.

Re: ZZ502 DUD questions
 

Those are the heads that come on a ZZ502...

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yessiree. But, ported with all valves, springs, hardware changed. Roller rockers and morel lifters added.

Re: ZZ502 DUD questions
 

How much gain did you see from the porting on thoose heads?

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Iron,
Richard should be on Crocketts dyno sometime in the near future. The Edelbrocks I must say responded very well to porting. I don't have the numbers in front of me but I want to say an average gain of 27 cfm was reached. The cams for these engines are very mild. My thoughts the engines should make around 575HP and be very easy on parts.

Chris

Re: ZZ502 DUD questions
 

Chris, I have all of the polished pieces back from the polisher. The billet stuff along with the cast valve covers look great. Some Zoot on them and won't have to do much to them except show them off. Motor being dressed next weekend (cooler, electrics, electronics) on a KE bell housing bracket. Then off the Tyler for some running. I choose to use the motor that had about 4 hours running time (in stock form) rather then and other crate motor that has 0 time.

I will keep you in the loop. Belated grads on the wedding. You did go thru with it, didn't ya?

Re: ZZ502 DUD questions
 

I read thru most of the replies on your post and didnt see any questons about your fuel system. The 330hp Mark IV you took out had a mechanical fuel pump, right? So what type of pump are you running now? If its a electric pump, it should be mounted low, and the anti siphon/checkball valve removed(@ the tank). I burned up a piston on 1 of my ZZ's in 98 when I first installed them. Turned out the electric pump cant suck good volume thru the checkball, resulting in low fuel pressure and insufficent volume to the motor. After installing a 1/2 fuel system, with 100gph pumps, the prob solved. Boat has ran great ever since. Never had oil prob you spoke about but I always had a 3"x18" oil cooler with 5/8" lines, I ran the 6qt pans for many hrs without any issues, but did put in the GM 8qt pans last year during freshen up's

Re: ZZ502 DUD questions
 

Great suggestions. I will add, regardless of you choose to use or not use a recir water pump, adding the merc pressure relief valve is good water pressure insurance protection. Considering you are running an external motor driven sea pump, right?

Re: ZZ502 DUD questions
 

Well, the progress report looks like this. I took the boat to Speedmaster Marine in Toronto, and they have already taken the motor out and found a few issues. ( like 1/2 inch reach plugs in a head that requires 3/4 ). The motor is now at Active engines ( as seen on Dream car garage ) and they are going to dyno it before and after to see what is up.

RT

Re: ZZ502 DUD questions
 

Well, they have the motor on the dyno right now after changing the oiling system and bearings. The motor made 489hp at 5000 rpm and 568 ft/lbs at 3500 rpm. This is a stock ZZ 502 with an 800 Holley carb.
They are now going to change the Intake, cam, springs, and move to roller rockers. The cam is an HP 500 cam. So it will be interesting to see if there are any changes.

RT

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Soooooooooo, anyone guess at how much the accessories will rob and how much less power Imco Powerflows make than dyno headers. I think I am trying to compare this to a real HP500 merc on the hp front in my head.
The HP 500 with Rec head, and this motor with Aluminum Ovals, but with more compression.
I was hoping to see 500 at the prop, but it sure doesn't look like it.

RT

Re: ZZ502 DUD questions
 

If you're going from a ZZ502 cam to a Merc HP500 carb cam, you are not changing that much.
A single plane intake will likely give you a little more up top.
I thought a ZZ502 has roller rockers from GM.
The HP500 was rated 470 at the prop and I think they dyno at around 520HP, so you're not far off...

Re: ZZ502 DUD questions
 

I think there is .10 more lift in the new cam and a few other things. We are also looking for reliability.

RT

Re: ZZ502 DUD questions
 

Pat, Stamped steel rockers on the crate motor. My info from Merc has the HP500 rated at 500 HP at the crank, and 470 HP rated at the prop. Interesting, the crate motor comes with an 850 cfm vac sec carb. My experiences with GM and their crate motors are that the published HP/TQ numbers are very conservative. Hmmmm. May do a search on HOT ROD mag to see if they have ever dynoed a ZZ502 crate motor.

Re: ZZ502 DUD questions
 

Yup you're right, stamped rockers, and 850cfm carb...

GM rates the ZZ502 502HP @ 5200rpm.

I checked Hot Rod magazine for a Dyno test. The only one I could find was a ZZ502 with an after-market fuel injection system. The tests showed between 508 and 528HP at 5400rpm.

So ROTAX, are you saying that Firewalker should be seeing more out of his ZZ502 stock?

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Mine came without the carb or ignition.
I would also think that every dyno is different. I will get a HP 500 chart from them also to see the difference.

RT

Do any of you think it would be worth changing the SS exhaust valves to Inconel?, and the head gaskets while that is being done?

RT

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Rob, waynes dyno is notoriously stingy on numbers. He likes it that way :) Under promise, over deliver!!!!

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Thanks Packer

Picking up the new sled on Sat...... you getting pumped up yet?


RT

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Geez, not another polarass I hope :)

Yep, the cats gone beddy bye for the winter, sleds will come out this weekend I guess.

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yep a new PULLYOURASS, I kinda got suckered into it.

Gonna Grass drag it on the 12th, up near port carling

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Yes, if all things are taken "back" to the GM bill of materials. He wrote that he ran a different carb and ignition. Not so much that the stock carb is slightly larger. I believe the carb set-up would make the real difference. And the ignition too. Who knows what ign curve was used in his distributor. My findings so far all show GM to be very conservative on their published numbers. GM never wants to have one of their crate motors ran on some builders dyno, and show less power numbers then they publish. Bad for business. News like that spreads like wildfire throughout the high performance market. You get the point. I wish I could find the article that was on the new ZZ572-620 HP motor. They found that motor, right out of the crate after breakin, ran well over the 620 mark at it's published RPM HP peak.

Re: ZZ502 DUD questions
 

Unless your really going to run the motor hard, and for long periods of WOT, the SS valves will be OK. But, that means running good fuel and propping for 5200, not 5600. Yes, change the head gaskets (while you have the heads off) to the .40 Cometic. $$$ but worth every cent.

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Just talked to the engine builder doing Firewalkers piece. Called him to tell him his new customized ball bearinged marine distributor is ready and he told me they just dynoed the zz502 after sorting it out. 562hp at 5400, 578 lbft. That should wake the little panchanga up some over the old 330 hp :)

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Yup, I have the DYNO sheet infront of me.

holds over 550 ft/lb from 3500 to 5300.

That is with a Cam change and Victor Jr. intake, still on the 800 cfm carb.
Makes about 45 more than an HP 500 carb apparentyl.

Yup the P-22 should RIP!.

RT

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Excellent!

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Any bets on speed, it ran 66 with the 330 on the GPS.

RT

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Hmmmm...My 23 Nova ran +,- 57 gps with a 7.4/330. With the ZZ502/502 dropped in, 70 gps is pretty common, 69 any time and up to an all time top end of 73.1, on a cool dry day.

I'd guess your speed will be somewhere between thrilling and scary :D

Be sure to check your steering out REAL WELL before lighting the fuse on that rocket.

Re: ZZ502 DUD questions
 

Thanks,

It has IMCO steering and a XR drive, soon to get a shorty lower.

It should be fun, I am used to 130mph STV's

RT

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Sounds like you're all set. Fun....that's an understatement. Sounds like way beyond fun :drink:

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figuring 30hp for the drive and 30 for the accessories, that leaves approx 508 PSHP so I figure around 15% slip with 1.50 gears and a 26 four blade if ya can pull it to 5400 will net ya 78mph dependant on load.

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Firewalker...first of all wow excellent build up. From everything I have read/know about the p-22's you should be up around 80 with no problem. Where are you located in canada. You guys up north love your pachangas....selling mine and that is where most of the hits are coming from. From others who have gone close to your setup with a 509 at about 525 hp they were getting 75 at 4900 rpm's and the peak rpm's for their motor was 5700 rpms...so that might give you a closer idea....I say 82mph. About a 3200lb boat with that setup and bravo and your hp, should be close to that...keep us posted.

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Good bet, packer, I am gonna say 82 mph. It ran 72 with the crankcase FULL of oil.

RT

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Yup we love them, you can get 25k for a good clean one. The key up here is WINDSHEILD.... short summers. And there is a region up here called muskoka, and on the 3 lakes they are somewhat trendy........ I wanna have the FASTEST one.

RT

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I think you should be right up there as being the fastest. Go with a 4-blade too, they seem to be the best on these hulls with bigger hp. If you know someone looking for a VERY clean p22 let me know. Clean boat looking for big hp. I hear ya about the windsheild....lot of people think the same way up by me in the 1000 islands. I will have to see what the new boat is going to be like without one

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I have a few with out, it is nice to have one with.

I have a 26 Bravo 4 blade to start, I think I am going to need a 28, and then I will order a labbed 28

RT

Send me some pictures of your boat, I know of a guy looking

twible @ roycap.com

Re: ZZ502 DUD questions
 

Well, I'd say your boat weighs about the same as mine.
I swapped from a 310HP/7.4MPI to a 415HP/502magMPI and gained 8-9mph to a top speed of 75-76GPS.
I'm guessing you will crack 80 with no problem and may see 82-83 if you can keep her running true.
An extra 230 ponies is quite a jump! :eek:
Good Luck!

Hey Firewalker, would you mind sharing the specs on that new cam?

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Rob, I have a 28 bravo you can try. When we going water testing, the lakes aren't hard yet :)

PatM, its a standard hp500efi cam.

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I hope to be boating next week with it to shake it down. The Cam is the HP 500 carb cam ( might be EFI ). The guys apparently were pretty shocked at how it the intake and the roller rockers woke the motor up.
Interestingly, the OEM rocker studs were LOOSE.

RT..... and low 80's would be a dream. I sure hope so.

Re: ZZ502 DUD questions
 

Thanks for letting us know how it turned out. It's interesting and informative to follow these things to their conclusion.