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STV_Keith

My new motor???

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YEP that worked KEITH and Yes using WMP...THANKS

Some pretty cool "brown" back drops...ours are "white" right now!!! ???  ???

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Well, after 10 hrs of running, I put it on the wood today.  Two up, with 3/4 tank of fuel and a 27 RE-3 Mazco, 91.6 @ 7300 is all she'd do.  Pretty disappointing.

So, back at the shop, retorque the heads and do a compression check...only 100# in most cylinders, 105# in #2 and 106# in #5.  That's encouraging, seeing that with the 135# it should make, it will have WAY more steam.

My question in, why is it taking so #### long to break in.  Now, this is an all steel sleeved motor with the chrome rings.  On John Marles' recommendation, I have been running 32:1 Merc synthetic since it was first cranked.  Could that be an issue?

Also, the water temp never gets above 100*.  Barely comes off the pin.  Water temp is about 50* right now in the lake/river...is that too cold?  I was thinking about putting t-stats or a smaller restrictor in to get the temp up...you need temp to break stuff in, right?

Any thoughts or suggestions guys?

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Very puzzling...

Something seems wrong with the compression and at 91 mph the boat still isn't working like it wants too.

I would not worry about the head temp. Cool Head is beeter then hot head

How bout playing with set-up some. Got a Cleaver handy :)

OK...I won't go there for now!!!

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Well, we're gonna make some changes this week and see what happens.  I'm going to put t-stats in it to get the water temp up.  So far, it's not been over 100*, mainly because our water temp is 50* or so.  This will help.

I'm also going to cut back a little on the oil (40:1) and go to a non-synthetic.  We'll see what this does and I'll report back after next weekend.

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If your running a full synthetic that might be your problem. I think US-1 was saying to use (if he did) mercurys synthetic which isn't a full synthetic.  Might want to double check that.

The pennzoil will lube too well I guess.

Seem to remember also that the engine has to be loaded down or it won't break in. Thats from those tronic loaded engines that monitor themselves and tell you when they're broken in. A few posted in the past that once they did this the puter set to broke in soon after. I think they used a big wheel and/or wieght(passengers) forgot now.

From the other post -you may have the wrong washers in. Water flows too fast. little restriction, like for a car without a thermostat.

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I have been running the Merc Hi-perf synthetic.  I'm going to go back to the regular stuff to try to quicken the break in.  I'm also putting t-stats in the heads this week to get the temp up.

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Keith..

You might try an ET wheel...My boat would never run right with the mazco 29...I had lots of torque..no water pressure to speak of and low temps..?? go figure...anyway I switched to ET clones of 28 and 29 (the old mazco cut to et) and now have all kinds of pressure and performance..the 28 turned 7500 or 97+mph...By the way what sort of rpm are you expecting

Cheers

JJ

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I'm going to self-impose the limit at 8k.  The old motor turned my 29 RE-3 7000, for 97.5 on GPS.  The new motor has so far (with 100# of compression) run 7300 with a 27 RE-3 for 91.6 on GPS.  I'm expecting way more power once it's broke in.

I figure to use the 27 for all around stuff with people - etc, the 29 for one-up playing and I have a 32 cleaver coming for top end stuff.

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Well, put about 3 hrs on it last weekend running the non-synthetic Merc oil at 40:1.  Also put t-stats in it.  Just ran a compression test and they are all up 5-10psi from last time.

Did a leakdown test which revealed 12% leakdown.  Normally, I'd be upset, but it just goes to prove that the rings haven't seated yet, so I know the compression will continue to come up.

I'll keep you guys posted.

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Well, here's the most recent update:

Did a leak down test a few weeks back and it's still at 12% (only did one cylinder).  Compression still 104-113#.  Basically, it's not breaking in.  Pulled the heads and shipped them back to Jim Ruck to have them tightened up to bring the compression up - but didn't, here's why.

While Jim had them, he spoke to the guy that runs G-force.  Now, I don't know this guy from Adam, but he hit on some thing.  First, supposedly this guy used to do the tuning on the F1 Merc motors at the races, so he should know something.

Anyway, here's the run down:  (JR = Jim Ruck, GF = G-force guy)

JR:  we're gonna tighten up these heads to get the compression up.

GF:  what's going on with the motor?

JR:  compression just won't come up.  Motor has been running for 15+ hrs.

GF:  What's the leakdown like?  High?

JR:  One cylinder tested, 12% leak.

GF:  Broke it in on synthetic huh?

JR:  Yes, then switched to mineral base at 10 hrs.

GF:  Have areas of the bores that are shined up and other areas that still show crosshatch?

JR:  Don't know.  STV_Keith:  actually, he was right.

GF:  You are wasting your time and that set of heads.  If you tighten them up, you'll force more exhaust past the rings which will heat everything up and eventually stick a ring or piston, and the heads - with the tighter cc's - will be unusuable the next time around.

JR:  What's the solution?

GF:  Rehone, new rings and put it back together on mineral based oil for break in.

So, that sums it up.  I'm gonna throw the heads back on it this week to run it in Havasu this weekend, then pull it all apart on Sunday.  Hope to get it honed and new rings in next week, and start the long process of break-in all over again in 2 weeks.

JOY!

I'll keep you guys updated on it's progress once again.

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Well, the new motor hasn't put me where I wanted to go, so I just broke down and bought a 2.5/260.  It needs a cylinder re-nikasil'd, and a set of rings, but that's it.  I'm gonna have the pistons top-pinned, the exhaust chest opened up and the rod slots done while its apart though.

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Why don't you get ruck to do the block and send the rods/pistons/pins to JSRE for a lightening and balance, the reed plate cut also helps as does the intake spacer (flywheel is a good idea too), he angle cuts the top of the pistons and that kinda has the affect of raising the porting, it will have a little more top end pull. Aim for a 8500 top rpm and it should live a long while..........oh and 35cc heads will help too. With the above you should have 300+ hp and 120mph......and you are gonna need a 32 cleaver.

RT

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Thanks RT.  I am going to have the pistons pinned and Ruck do the other stuff.  I want to do the spacer, but that can be added later (in lieu of more money now).  How much of a difference should I see with the lightened pistons/rods/pins and the angle cutting on the pistons?  Noticeable?

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