Kingsley78

Kinda looks like the plugs wernt hot enough but you would see that in both domes. Maybe one carby was out in its jetting. The left one looks sooty, like its rich but im no pro...

I sent dlnos a pm. I guess il have to make a note to him that il require it to run using the USA 93 octain?

Port timing? Have you shifted your bores up with a thicker base gasket to give TDC piston clearance?

Anyone?

Im still virginal around this site. Are you able to drop some of the site builders names or how to get in contact with Redline, preferably an email or website?

Im in the need of custom domes for my 4mm stroker with a cool head. Im running blaster piston so i need something to suit. I will be able to give piston height above deck and port heights to determin the compression ratio, so i gain the maximum use from 98 octain fuel. Can anyone help or recomend some help. I have Paypal Kingsley

Sounds like the water pump seal

Im not a pro but it sounds like your motor was built to run high octane and by using 87 octane, you made it detonate from the first bang. Im guessing it was detonatin so bad that the fuel was becoming unstable long before TDC and pre-ignighting the fuel, meaning when it was time for the spark to normally ignight it, you had no fuel or very little left to burn. You would have slowly been chipping away at your pistons, causing them to leak and lower your compression and crank case pressure, also causing power to drop fast.

Ive made a gastket to suit my 4mm so that my pistons dont go beyond the deck. If i lower the bores with a thinner/standard gasket and run custom domes, how will that effect my port timing?

Can anyone help with an idea of my porting. Ive only messured the exhauste and the top of the port to the deck is 28mm and the bottom of the port to deck is 55mm. Ive got a feeling they are high as im not seeing a very high compression ratio. Cheers

Im running a 66.5mm bore and 58mm stroke (4mm stroker) . Where have you taken the figures from? Im guessing i delete the cc space that the head of the spark plug would take up or isnt this a concern?

Yeah it makes sence and it sound like im understanding it all as i go. Id like to get away from the use of race fuel as its over $2 a ltr over here in Aus. Im going to deal with some machinist and experiment at increasing the domes CC's in the chambers once i get them until i reach a ratio that will be safe on 98octane. My ports must be fairly high then plus the balster pistons to return a 100psi reading. I have to measure them when i CC the engine and will compare then to stock.

Thats right but it does change the ratio.... How do i work out the cc of the piston with the dome above the deck? Do i messure the cc from the shoulder of the piston to the deck, then add the squish thickness and minus the piston dome cc from the head dome?

I bought a jet ski for that..... Not a good ides to put your shee through water anyway, makes the seat slippery.

dajogejr- You are probley very correct with your susgestions. Im yet to know what my ratio will be until i recieve the domes and cc it all. I may still increase the dome size if fuel is going to be too much of an issue. Im not looking forward to the extra maintenance that comes with methanol so that could be the deciding factor for me. Im running trued and welded 4mm Hotrods crank, Some kind of porting (came with the bike), blaster forged 66.5mm pistons, cool head but with banshee 22cc domes. I went looking to see why i wasnt getting power that i expected and learnt that my domes wernt suited and were only giving 100psi and the full build. I think i was given some wrong advice and ordered the 17cc domes to suit blaster pistons. Im just trying to cover all options to make this package work for me. At this stage i think i may be increasing the domes size to work with 98 octane pump fuel.

Ive gotta pull my head off soon to fit 17cc domes. Id like to cc it to work out the corrected ratio. Ive never checked the CC's on an engine with domed (blaster) pistons before. Whats the way to go about it? Prevoisuly ive filled the cylinder at TDC with trans, with perspecs to fill it to the deck and done the same to the combustion chamber in the head, then messured the amount of oil. My memory 1ml of oil equalled 1cc id area, it this correct?

Hi guys. Ive got some 17cc domes on their way and im expecting the compression to be right up there. Im concidering running 98octane pump fuel, spiked with AV Gas to bring the octane up. Or.... Run 100% methanol which is easier to get than AV Gas. I dont know much about it but i understand i will use alot more (not a problem, 20ltr tank(, il need bigger jets and something about needing to flush it after? Whats it like to start a cold nike on Meth? Will i need to start it on petrol? Lastly, will the internals of my Keine carbs and and fuel tank be ok with Meth in it?

Too lean can do it and too high compression also. More so if you have both. Too much advance in ignition aswell.

It looks like detonation has caused that, note the broken ring gland.

What octane fuel are you running with 165 compression?

Thanks rick, that helps to clear things up a bit. This was my first ever 2 stoke build and im learning along the way. The main problem i found was that the Blaster pistons have a higher pin, meaning the piston crown was sitting to low in the bore at TDC and also sending my porting out of tune. After lowering my bores 1.5mm by taking out the 2mm spacer and making a gasket to give 1mm squish, i found that ive corrected the port timing and positioned the piston higher up in the bore, where it should be sitting correctly. Im running the Blaster piston because my stock bores were at the end of their life and i needed to take them out to 66.5mm. The place that i bought the 4mm kit from said the blaster piston would fit but was unsure on the workings, looks like i got sucked in but not a bad things as im learning. One thing im still concerned with, regarding the domes i linked above. If the blaster pistons normaly sat lower in the bore on a standard crank in a banshee engine, then maybe those domes might sit inside the bore slightly, meaning il have to raise my bores again with the 2mm spacer and end up screwing the tune on the ports. I doubt that would happen as they are listed to work on 68.55mm bores and i asked if they will be suiting to 66.5mm bores, which makes me think no part of the domes go below the deck.

I understand what your saying. If id simply removed the spacer, then yes the pistons would hit the head but ive made a base gasket thick enough to give me a 1mm squish with my cool head running banshee domes. The pistons dont go above the deck or they wouold be hitting the head. Its been a while since i put the motor together but i think its a long rod. All that i can work out now after having a 1mm squish is that the blaster pistons have a different angle on the dome of the piston and the cool head domes would work better if they were cut at the same angle. What gets done to the domes when running a 4mm stroker? and is it relevant since i have a 1mm squish I cant pull the head off as the bike is 700km away while im at work.

Can you explain what is done when cutting domes for a 4mm with blaster pistons? The items on ebay are suited for blaster piston in a banshee. What other difference is needed to the domes for the 4mm. As stated above, im in Australia, Its not easy for me to deal with companys over there.

Bump