Too Hot?

[axo]

410+ degrees beyond 35MPH with my setup.
Wheelman im following your thread on Flash 4.2 because your setup is kind of similar to mine, but you seem to be getting better temps. I am on 45 - 122 jets now. And i feel it kind of gargling in gas and sometimes i get 4 stroking when the engine is warm and i gun it from a stop light.
I do not know if this is the right thing to do, but i tried running with the choke on to see if the temperature went down but it stood the same.
I can use only 1/2 or 3/4 of the throttle.. beyond that, i just get more noise and more air into the engine but it bogs down without any further acceleration. Could be because of the restricted CDI. But with these temps i am not interested in removing the restriction for now.
I am using a NGK BR8HS, 927 castor oil and premium gas. I disabled the power jet from the oko as Bakaracer suggested.

I wonder whether the shroud around the cylinder is working properly because it is not "tight" and "sealed".. the spark plug cap does not seal the top like it used to do with the stock cylinder and head, and the area around the ct manifold has a big gap too, plus the fins of the jug are pretty much in contact with the plastic too so i cant see how the air could be circulating in there efficiently.

Do you guys get better refrigeration by removing the clutch cover or have any other suggestion ?

Thank you.

[tw39515]

im running a corsa with a oko 24, 8.4 gears, 7 gram rollers, keli variator, 1500 triplets, 1500 center spring, rear trans cover off. running 48/132 jets hitting close to 60 mph with a v8 pipe and temps are running 350 to 360. oh yeah needle one notch lean.

[Wheelman-111]

Greetings:

What was your baseline compression, AXO? 4.2 was pretty modest, on purpose. Anyway I don't completely trust my gauge, except to compare results on my own engine. I used JB weld to secure it to the headbolt ring, and not the spark plug, so my "300" might in fact be the same your "400" degrees. If your plug is coffee or darker (and it hasn't seized...) don't worry too much. The behavior you describe is similar to mine - a softening of power when the throttle exceeds 3/4? My plug is still "espresso" dark, and I'll be trying a 120 - 118 next week over a 45 Pilot. It's reassuring to see the gauge jump down from ~350 to ~300 when I release the throttle.

You are probably still too rich based on the behavior you describe. Focus on the spark plug and performance, but don't forget the possibility of a vacuum leak. Check the tightness of the exhaust gasket, head bolts, crank seals when you get a chance. Maybe squirt around with something flammable to see if the idle speed changes?

The shroud can't and shouldn't be airtight everywhere, but I did use some muffler tape to close up the oval hole at the spark plug. The air that goes between the fins is not wasted floating above them.

TW it sounds like the Corsa needs a lot bigger jets than even the 86cc mini-stroker Char-Mo 50? What does your plug look like?

[tw39515]

havent checked it latley. temps only seem to get high at speeds over 50mph. i tested with a pipe similar to your hot surface pipe but used smaller jets and temps never got over 350. i hit a 62mph with corsa but cant rember what pipe i had on it or the rollers i was using. done so much changes and cant seem to get back up there. im sure its rich with a 135 and a 140 it was four stroking 132 seemed just right.

[axo]

I did a compression test like a few weeks ago and got 125. Might be lower now that the break in is done. I have to deal with the clutch problem i have on this thread too ( http://www.hondaspree.net/phpBB3/viewto ... =4&t=16405)
I have jbwelded the temp probe like 5 times to the custom copper ring in the sparkplug but i keep pulling it a bit with my leg when is hot and it gets disconnected..

So what is the melting point of the piston or head anyway or maybe not "melting" but some temperature that would damage it?
And what is the maximum Castor oil can withstand?

[Wheelman-111]

Greetings:

The Nikasil saw the temp gauge get a bit over 500 a few times with nary a scratch or scuff. I suspect a lot depends on how long the temp stays up there as well as how high it gets. Also, coast-down temp spikes are less disturbing than steadily climbing reading at WOT - since the engine isn't actively producing as much heat on coast-down, the spike resolves quickly with a throttle blip. At least that's been my experience.

I gather the Corsa is pretty tough, and both the Contesta and Malossi I had also withstood much higher temps than the two RUIMA bore kits I installed. Maybe there's a reason the Italians don't dare go bigger than 47mm - those lower cylinder skirts were pretty thin on the 51s, look Paper-thin on the 52s, so be careful. I have a feeling they warp when overheated and start to "hug" the piston skirt. (Note: That's just Wheel-Theory...)

Most synthetics will retain viscosity at higher temps than most Dino oils. How High? Who knows? CHTs above 400 scare me a lot.

[axo]

thank you wheelman.
Problem is.. lets say the temps get to the 400+ point, then i slow down to +- 30 but the temperature does not go down much at least that i stop at a light and the engine idles for a while then i get around 320 again.

[bakaracer]

You still didn't bump up that pilot yet? that 45 pilot is to small with that 24mm carb.bump up to a 50 .when the temps don't drop when you close the throttle,thats telling you that the pilot is to small.what oil to gas ratio are you running too?

[Wheelman-111]

Greetings:

Baka-san is correct. I'm getting good results with the 45 - the temp drops 25-50 degrees when I drop the throttle. That doesn't guarantee you'll see the same results. I'm using a fairly restrictive Hot Surfaces pipe that probably has some effect, plus the porting, compression, etc. are different enough that some people run a 45, others need a 48 or even a 50 in the same carb.

[CAPT]

Delete

[bakaracer]

Axo,

Try a 48Pilot and 130 or 132 Main if you have a very free flowing filter.. There is no way in * that a 122 is too big..

im running a corsa with a oko 24, 8.4 gears, 7 gram rollers, keli variator, 1500 triplets, 1500 center spring, rear trans cover off. running 48/132 jets hitting close to 60 mph with a v8 pipe and temps are running 350 to 360. oh yeah needle one notch lean.

accually it can. I'm running a malossi mhr cylinder with a sectional muffler with a 24mm carb and the 122 is the biggest jet i used so far and thats with a uni filter. if you don't know what the mhr cylinder is, its a full race bore kit that runs a 13.5to1 compression ratio that makes 9hp.

[CAPT]

Delete

[bakaracer]

Either way, I will bet ya $5.00 his main is too small.

I'm not doubting that the main is to small. I just was stating that 122 main can be to big and at the limt too.

[bakaracer]

thank you wheelman.
Problem is.. lets say the temps get to the 400+ point, then i slow down to +- 30 but the temperature does not go down much at least that i stop at a light and the engine idles for a while then i get around 320 again.

what does the temp do when your at wot and hold it there for a bit? did you do plug chop to see what the plug is telling you?

[fastplastic]

coundnt a vacuum leak elevate your temps too...