baja36ft

You said you used 0.27 head gaskets who make them and
do you have a # for them???? thanks.

Linster

They are Cometic. Part Number C5333-027. The numbers after the dash are the thickness. When you get the head gaskets they have a totally different part #. I emailed Cometic, and they say they package different part numbers than ordered. Did not make much sense to me.

http://www.cometic.com/catalogs/AutoCat04.pdf

baja36ft

THANKS redoing my 500's and thought i would check that out!!!!!!

Linster

Got the ECU's back from Mark today. Will do a test run on Sunday.

t500hps

I know your happy about that...bring a rain suit

Linster

Got back from a week in Sarasota. No problems other than the engine vapor locked on me the first day. Looking to get the mechanical fuel pumps soon.

I want to thank Mark @ Precision Marine for all his help. I sent him the ECU's three times for adjustments. He turned them around that day & got them back to me the next, THATS SERVICE!!! Every time I called him he took my call. He did not try to push me off with questions. A very nice fellow that cares about his customers. I can not say enough about his help.

The right way to do a modification like this would be to send him the motor. We got it but it took a few tries. He told me it would.

THANKS!

Top Speed trials coming next week.

Strip Poker 388

Lennie congrats on the engines. Ill try to call ya Tuesday. We should be finished Monday on mine

Rob

Linster

Here's the first top end results.
Last year the boat ran about 5300RPM that was 88MPH.
After the upgrades, yesterday it ran 5700RPM that was 93MPH.
I was expecting more, but has usual, the result seems to match the power. Assuming the 500's had 500HP, that was 88. The 525's have about 540HP and the boat runs 91MPH. Thinking I have 575+-HP, I got 93MPH.

Here's some things I noticed. Mid Range is much better. It has much better acceleration. Getting to 5700 happened quick then it hit the wall.
Running prop slip figures my slip went from 12%at 5300 to 14% slip at 5700. The speed took a minute to catch up with the RPM. I bought a set of labbed 33P props I will try next. I think I ran the engine out of the power curve with the 30's.

After a few WOT tests, my transom was sooted very bad. Even got up on top of the swim platform. I am going to do some plug checks next test. I would say the whole fuel curve could go down about 2 jet sizes in a carb. Maybe four. It might need a little more calibration on the computers.

Not sure when the next tests will be.

I still believe the best way is to send the engines off to the dyno to get the best result. I am seriously considering this now.

39 Unlimited

Congrats Linnie, I'm sure you'll find another 1-2 MPH. Keep me in mind if the 33's don't work.

Also, I have a set of 28 Merc labbed five blades for sale, still in box only used once.

Linster

Talked to Mark at Precision today, He just finished another engine very similar to mine and thinks he can improve on the result. I have decided the best way is to send him one engine and let him dial it in. He will get all small issues corrected. I am removing one engine Thursday evening and shipping it to him Friday.

Other things he told me. A 500 EFI intake will not work after 5700RPM. He says it runs out of air. He said I need to run it under 5500RPM to get max power. I am planning on talking a long lunch either Wednesday or Thursday and installing the 33P Bravo 1's to see the result before I send it to him. I feel sure he can get another 20-30HP out of the engine to get the fuel curve just right.

I will post these results as soon as I get out.

I made one call to Precision today, got Mark right to the phone, He talked to me and has been following my post and knew what I had done. Thats Great as far as I am concerned!