Clueless87JFrame Posted April 11, 2017 Author Report Posted April 11, 2017 Didn't snag a ring they are both still fine. Only smeared the aluminum on the cylinder in that one spot. Ring end gap was good (always check that) and the other piston looks perfectly fine is what is throwing me off. The pic of the piston was as soon as I popped the head off. Sent from my iPhone using Tapatalk Quote
Clueless87JFrame Posted April 11, 2017 Author Report Posted April 11, 2017 Well didn't mean "fine". Meant not broken rings Sent from my iPhone using Tapatalk Quote
sleeper06 Posted April 11, 2017 Report Posted April 11, 2017 Those are 513 series pistons and you put a 12* angle on the dome why? Squish band is hella wide and is a convergent angle which is no good. Out of curiosity what was your jetting set at? Quote
Clueless87JFrame Posted April 11, 2017 Author Report Posted April 11, 2017 Well like I said. The original engine was ported and built by "OFR" whoever that is in CA. They put the head and pistons and domes in. All I did was sent it off to be bored, then rebuilt it thinking that wS all there was to it Sent from my iPhone using Tapatalk Quote
sleeper06 Posted April 11, 2017 Report Posted April 11, 2017 Rule #1 on break in , over octane if your unsure . So you had wrong fuel, wrong dome angle, possible air leak, possibly lean jetting Quote
Clueless87JFrame Posted April 11, 2017 Author Report Posted April 11, 2017 Exactly why I asked yalls opinions haha - I knew I had something messed up. Outboards are much easier. Less porting - and easier to fix usually. This was my first go round and I'm still learning. $4-500 mistake but hey - at least there isn't a rod hanging out........yet Sent from my iPhone using Tapatalk Quote
Clueless87JFrame Posted April 11, 2017 Author Report Posted April 11, 2017 So with those pistons - which cool head would be the best to buy ? Which domes? And as far as ports - I was told they were ready to roll so that's why I put her back together. The port in the photo doesn't look good because it has aluminum growing on it. They looked great before I put it together - and the other sleeve/ports look fine. No scoring or compression loss whatsoever Sent from my iPhone using Tapatalk Quote
edgehanger Posted April 12, 2017 Report Posted April 12, 2017 513 pistons have a 13 degree rise. Your domes have a 12 degree rise. You need to get a chariot head because trinity heads will only accept a trinity dome and I don't think you can get a dome from trinity anymore nor would you want one. Contact driveline or noss to get proper domes cut. Tell them you have 513's. You need to know your deck height so you can get the proper squish you want/need. Most off the shelf domes have .030" step cut for stock stroke Quote
sleeper06 Posted April 12, 2017 Report Posted April 12, 2017 For pump get a 21cc dome from driveline with a 14* angle 9-10 mm wide band. Where was your jetting at? Those cylinders have port work so I'm just curious. As far as outboard goes I've been building and porting them for years and they are much more difficult than any shee engine once you get a handle on it. Do me a favor, measure from top of deck to top of ex port in mm if you can if not I'll convert it Quote
Clueless87JFrame Posted April 12, 2017 Author Report Posted April 12, 2017 For pump get a 21cc dome from driveline with a 14* angle 9-10 mm wide band. Where was your jetting at? Those cylinders have port work so I'm just curious. As far as outboard goes I've been building and porting them for years and they are much more difficult than any shee engine once you get a handle on it. Do me a favor, measure from top of deck to top of ex port in mm if you can if not I'll convert it Yeah those are easier for me because I've been running and playing with them for 25 years haha. My first banshee and so far it's been a little nightmare. Yeah it was ported when I got it - then ports cleaned up again a few weeks ago before I rebuilt it. I'll measure it and see what I come up with. I left the jetting the same in the 34mm carbs since we didn't really change much just cleaned it up and rebuilt it. Sent from my iPhone using Tapatalk Quote
Clueless87JFrame Posted April 12, 2017 Author Report Posted April 12, 2017 Not to throw you off topic... but whats it cost aprox to do a full outboards rebuild (crank to bored cyls pistons ect) on lets say a triple 75hp merc. How old is it ? Sent from my iPhone using Tapatalk Quote
Clueless87JFrame Posted April 12, 2017 Author Report Posted April 12, 2017 Well the one in question is a 1992. Go play with some BBC ya demo lover. He's on the right track from now.. 4 pages in, its about time for a slight derail 92 model - get on boats.net and order what you need. You can usually get away with ball honing those cast cylinders and slapping some pro-marine pistons back in, bearings (if needed) seals and some Loctite anaerobic gasket maker and torque everything back. One piece cranks so it's much easier. If I was going to guess I'd say $1000 or less Sent from my iPhone using Tapatalk Quote
Clueless87JFrame Posted April 12, 2017 Author Report Posted April 12, 2017 So this head ? Which domes ? Sent from my iPhone using Tapatalk Quote
Clueless87JFrame Posted April 12, 2017 Author Report Posted April 12, 2017 Get a hold of a builder on here is your best bet. FAST or Driveline.... Get the port measurements for SLeeper to find out your duration then report those specs to the chosen builder and let them either cut you some custom domes or order some shelf domes they think would work.. or even get sleeper to get domes for ya... I can machine them if needed no problem. I'm not trying to win races I just want it to last at least a few runs more than it did the first time. Sent from my iPhone using Tapatalk Quote
trickedcarbine Posted April 12, 2017 Report Posted April 12, 2017 Does anyone see what I am not seeing?Zero way it sealed up. Quote
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