I’m not using the heads so if the bolt breaks, at least I can get my header off. It’s between two header tubes... really tight.

I have it soaking in Aero Kroil. This stuff is supposed to creep into everything. I actually had the idea using my hoist to try picking up the other end of the header to make the header break the bolt free. Hoping the penetrant will work. I’ll hammer a socket onto it tomorrow to give it another go.

Welding a nut won’t work. It’ll need to be a bolt. There is very little clearance between the bolt and the header tube.

I might be able to get my die grinder in there. My angle grinder won’t touch it.

I’ll grab a pic in the morning.

If it is that far gone just grind a flat spot on the head or what is left and center punch it really good, drill the head and it will pop loose.

That was also on the list to try.

TomZ,

I have some sockets that have something like a tapered reverse thread chisel. (Not sure how to describe it) As it tightens on it pulls the bolt / nut in farther and tighter. I used it on most of the bolts and studs on a 68 Vette I was building. The Vette was from up north, needless to say A LOT of rust. I live in Fredericksburg and it looks like you are in VA Beach. I could meet you in to Tappahannock if you want to borrow them.

Appreciate the offer but I managed to get it.

Kroil did not work so I had to really dig into this to see what I could figure out.

I started off with my air cutoff tool that was just a little too big to fit. It helped to get started but I nicked a header tube so I had to look at other stuff. Digging through my tools. I had forgotten that I had a Dremmel cutoff wheel set with its own shaft. Surprisingly, it fit within the chuck on my straight grinder. The wheel took the head right off. I then switched to stone to dig into the bolt shaft until I could see the line around shaft. Tapped the header and it fell right into my hands.

Now we’re getting somewhere!

What headers/tailpipe setup are you using?

CMI E-Tops with CMI to the transom tails.Heavy system... I understand now why they might have cracking issues with the Merc-spec'd exhaust systems.

sure looks pretty!!! We’re the tails custom made or was it something they had. I noticed I had a hard time finding anything for trs. Trying to do some ahead of the time research for my hopefully future boat.

Looking at the paperwork (from memory) I believe the tailpipes were custom made for the boat. I can take pics and measurements if that would be helpful.

awesome maybe in the future but not needed right now still in the early stages. Thanks though very much appreciated

Some updates...

I'm sure some of you saw the piston fiasco over in the Tech section. The piston ring stuck to the bore and broke the ring land and ring. Half of the ring was gone. Ouch! I broke everything down and now the block is at the machine shop getting cleaned up and bored. So far, no cracks and pressure checks are good so we're moving forward. The crank was also fine needing only a polish. We're boring the block to 4.5 inches and taking about .006-.007 off the deck which; that should give me close to a zero deck. So now I need to decide on pistons and rods. Compression is going to come in around 9.5:1 and with my heads should still allow me to run on 87. I have 500 EFI cams (169621) to go with my AFR 325s. It's been suggested that I bump the cam up to at least a 741 (168741) but I'm not really looking to spin it hard. The heads also make milder cams bigger so hoping I can go this way. The duration split, though a little milder, fits the profile of the head better. I may step up to a 1.8 rocker on the intake to really get after it. Open to suggestions.

Once I have the number one block back from the machine shop, I'm sending number two off to have some of the same treatment. I'm hoping I won't need a bore on that one. I will more than likely replace the pistons since I'll be doing the rods in that one too. The rings are just too expensive and I'd rather not have to worry about blow-by, etc.

Headers. Pressure check using air, water, and heat. I'm happy to say there were no leaks. And to combat any potential issues down the road, I plan to install dumps at the transom that will drain the headers after shut-down.

It's starting to come together.

Worked like a charm!

And while my Formula waits on new powerplants, my buddy's Cig Bullet will be over here getting finished up from its engine builds. Taking over the final rigging and finish work from another friend, and I'm hoping we can get some good steering installed while it's here. We'll be running about 1300 HP so it's time to make it safe, too.

I'm sure the neighbors are going to love having two offshore boats at my house!

good to hear it’s starting to come together. Curious how you plan on doing the dumps/drains? This sounds like a good idea and would like more info on it. Any thoughts get or still trying to figure it all out?

Thanks!

I have it figured out for the most part. It’s been done by a few guys here on OSO so I’m just using what I’ve read/learned.

Basically, I’ll add fittings at the back of my distribution tubes, and then they’ll go out to fittings on the transom. The fitting from the tubes will neck down to a -4 AN fitting and hose then connecting to a corresponding fitting on the transom. No ball valves are involved because water flow and pressure will follow the path of least resistance while running. When you shut-down, they drain.

Tom I really like our 500efi cams. I agree with your statement that the good cylinder heads make them seem bigger. Easy to get them to idle solid for shifting gears and still run up well into the upper 5k range. Really need to take a look at how you boat.. idle time... cruising speed.. etc. Those 741's are gonna make quite a bit more power in a lot of areas but there is always a compromise.

Thanks Tyler. The boat is never going to be the fastest out there. Hull mods, drive changes, etc; I'm not keen on doing anything like that. I'd look at getting a different boat if I wanted something like that. Building a strong cruise with the ability to turn 55-60 at a lower RPM with the ability to approach upper 70's to 80 here and there is what I'd really like. I think that helps point me in the right direction.

9.5:1 is really pushing it with 87 octane without knock sensors and efi
you need to pick pistons before you’ll know what the deck height will be, and final compression ratio
dont drain you’re headers until they have cooled down. The water will pull the heat out long after shut down and insulate the outer tube. Dump the water once after running and see how hot the tubes get while sitting. That heat cycling is way worse for the headers. Draining them when shutting off should only be done if you realize you have a leak and don’t want the water draining into a cylinder.

Not seeing 169621 in the catalog. Do you mean 721? 500efi was a 731 I thought.
721 214/220 .553/.564
731 226-236 .587/.610
741 236-244 .610/.632

731->741 was worth 25hp or 5% at least for Merc. A 721 would give up a lot.

Are your heads full CNC chamber? Getting some duration over .600” lift would appear to be worth a lot of power. Probably 30hp at least going from .550-.600 on its own.


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https://cimg2.ibsrv.net/gimg/www.off...6f9000b4e2.png

You're right about figuring final compression. I'll know more once parts are all together. Would 9.5 and 87 really push it with aluminum heads?

On the header dumps I hear what you're saying. I had considered this but thought (assumed) that with others doing similar this wasn't an issue. I'll need to rethink that a little more. Maybe a much smaller restriction to slowly drain the water? I'm not concerned with leaks since really checking them over, but I had a good amount of water that seemed to make it into the rear ports. I was thinking draining would also limit condensation. I'm open to any and all suggestions on how to go after this the right way.

The cam is the one spec'd for the 500 EFI and it's not in the catalog. Grind number is HR-292-2S-14 IG, .598/.610, 230/236 @ 050, 114 LSA. I will probably run this with a 1.8 rocker on the intakes to help get the exhaust in-line some (so lift would be .633 on the intake). Mine have the tulip-Inconel option so the exhaust port will be very aggressive and potentially over-scavenge. Boosting the intake side would help to get after this. From everything I've read, this is a good direction with that head and really close in terms of the recommended split in duration. I know others here have done similar.

The heads are as-cast with whatever CNC work AFR does to them prior to the full CNC option. They would fall under the partial CNC flow sheets though I think the exhaust flows more because of the valves.

[QUOTE=TomZ;4760964]You're right about figuring final compression. I'll know more once parts are all together. Would 9.5 and 87 really push it with aluminum heads?

Tom, The motors we built for the Monkey were 9:5 with 335 AFR aluminum heads.....I had to run 93 octane fuel...She did not like 87 at all

[QUOTE=badmonkey;4760970]Thanks Chris. If I have to run better fuel that's okay with me. My only concern is finding it. The place I keep the boat in the summer has 93.

What's the cutoff point with octane and aluminum heads? 9.25? 9.0?

[QUOTE=TomZ;4760972]Do not exceed 9.0 is my opinion. I’m sure others may feel differently however.

Even at zero you will need 4 cc of dome to get to 9:1 with a 121 cc chamber and a 040 mls gasket. If my math is right. These Wiseco pistons should be close with a 3.8 dome. Part no. PT077H3. Sorry for not having a link. If you go to 4.25 stroke, a flat top will get you a perfect 9.1-9.2 ha ha. It’s only money. Good luck Tom

Thanks Roscoe. I believe my heads are 118 maybe a touch under. They need to be surfaced to take care of some corrosion spots because of running on GEN VI blocks with open cooling I was going to take them down to 114 to work with the original pistons per the original plan, but since the one piston messed up and required some boring to fix, I got it in my head to Go higher with the compression, etc. I’m still working on the final configuration.

I’m open to any and all suggestions on this so please keep them coming!

My initial rough math based on having the block decked to zero or close to (.001-.002, we’re not final just yet... it may need a touch more than that), using a SRP replacement piston (1cc dome), 039 gasket (FelPro 17048), and the 118 head was putting me at about 9.2. Taking the heads to 114 would put me at 9.4 and change.

Final numbers will be figured out once I have all the measurements in-hand.

Any thoughts on my idea of bumping up the intake side with a ratio change? If I go to a 1.75 Crower rocker, I would be at .616/.610 and probably close the duration spread to 232/236 @ 050 (or 231/236).

I would personally would want dry exhaust to safeguard all of the time and money you will have tied up eventually. Keep posting progress, I can’t wait to see how many prop sizes you have to go up.

Which Crowers were you looking at? I'm digging the shaft mount bushed tip, they will do any ratio you want. I was looking at these for my merlin 3's ..
https://www.crower.com/rocker-arms/w...t-rockers.html

Those are nice! But holy hell pricey! I'm using Crower's Enduro stainless steel rockers for mine.

For my old 311, I think that sticking to basics is probably a better idea than getting too deep in the weeds on power production that just won't make a lot of difference with this hull and the configuration. So with that said... sticking to the 500 EFI cams that I have (114 LSA version of a 761 for those that do not know the specs of a 621) and keeping compression at 9:1 or so should get me a decent, reliable package that I won't have to work on all the time (easy on springs, good dock manners, etc). I think my original goal was to try to hit 80. I think I have the parts in-hand to get there. Hell, I had no idea that the one engine was so hurt. I was already doing 70 with a bad one. With the new power and the reduction of the weight from the heads and removal of all the EFI crap, gaining another 8-10 MPH shouldn't be a stretch. We'll see.

It's so easy to get wrapped around the axle trying to get everything figured out. OSO has a wealth of information, but sometimes there's just too much. There's also a lot of conflicting information. And through my reading, I've found that some proven builds were being "corrected" by those that could profit off of services (and where in some cases people ended up with less than positive and sometimes even disastrous results).

Appreciate all the help! Keep the suggestions coming please. How about Scat or Eagle IR bushed rods? Thoughts?

I am 100% behind your newest plan. That cam is time tested and makes ample power and sounds great doing it. I am running a comp copy in my 540. I know that I left some power on the table but the reliability and the fact that I could still run my e- tops made the choice easy. As far as rods go, It’s hard to beat the eagle H- beam with floating pin. It’s great stuff for the money.

This had pretty much been the plan all along. I just got myself all spun up when the thought of leaving power on the table came into the mix.

“Must have more power”

”Must go faster!”

If I really want to go competitively fast, then really I’d need to find another boat. I know of some incredibly fast 311s, but the work involved to get there just isn’t in the cards. And I really love my boat for its old school style and comfort. That’s not to say it won’t be fast (it better be!!), but going after an extra mile per hour or two just doesn’t make sense. I did that with my 242 and it was more of a headache than anything.

I’m headed to Key West for some r-n-r tomorrow, but when I get back, I’m diving into it. I also have OSO member Hollowpoint’s Cig Bullet here at the house to finish up. Hoping to get new steering in the boat before the cold sets in. It’s got a new set of 650 horse blower engines!

Hey Tom, don’t know if you are flying into KW or driving down, but f you find yourself on Cudjo key please do your self a favor and grab a meal at the Square Grouper. It’s the best sea food I’ve had anywhere. Have fun!

Thank you sir!

We’re flying straight into Key West and staying on Duval St at the Pier House. We might rent some scooters to ride around but for the most staying put right in the thick of it. Hoping the weather stays decent.

Next time we go we’ll drive down to check out more places. The two other couples joining us are driving in from Miami. I’ll make sure to give them the recommendation!

Wow! What a trip! I’ve been to a lot of places, but I was sad having to leave Key West. We hit quite a few spots while we were there. Wrapped everything up at Capt Tony’s.

Back to reality and work.

Called the machine shop. They’re waiting on the pistons and rings and the rods from me in order to do the final finish hone and balance the rotating assembly. I was waiting to hear that the block passed porosity tests after boring so since we’re all good on that front, I ordered the parts. SRP 1-cc dome 4.5 replacement pistons, JE plasma-moly rings, and Eagle H-beam rods. Stuff should be here throughout next week, and I should have the block and balanced rotating assembly back at home in the next couple of weeks.

I have the other one on the stand now. I’ll get the rotating assembly out of it this weekend and then I’ll measure everything. Hoping I can just clean, deck and hone to run a set of replacement 4.47 pistons. New rods will be coming for this one too and the whole thing will be balanced.

Expected delivery from Amazon was Wednesday/Thursday. I got the pistons and rods this morning. Nice!

Just waiting on the rings.

I guess something is up with the site... can’t load the page to upload pics. The pistons and rods sure are pretty!

Work is coming along.... the first short block should be finished sometime next week. Then the other one goes out to be cleaned up. I probably won’t get the engines to my friend for dyno tuning until after Christmas but at least it’s coming along.

Tom, did you decide on lifters yet or did I miss that part?