My new 2276 running too hot

[damo67bug]

Hello,

I have just built a 2276 for my 67 Beetle but it is running too hot and I am getting some detonation when accellerating hard / opening the throttle fast. If I increase the revs slowly it seems OK.

This is the basic engine spec and how its set up at the moment:

2276cc
FK87 and Scat 1.4 rockers
11.9:1 c/r (1.5mm deck, 42cc)
CB Super Pro heads (44x37.5)
MSD ignition
48IDAs - 40mm venturi, 65 idle, 170 main, F7 tubes, 200 airs, 55 pump jets, 3 progression holes
3.5psi fuel pressure
97RON fuel
NGK DPR8EA plugs

I set the timing at 32 degress to start with, but have lowered it to 28 to try help with detonation.

I have an Autometer head temp gauge (with the sender at number 3 in a tinware screw thread near the manifold) which reads 400F when hot. My oil temp gauge reaches a max of 210F.

My plugs looked like it had been running too lean, so I have tried bigger idles - was 60, now 65. I changed the tubes to F7s at the same time as changing to 65 idles. I was running F2 tubes with the 60 idles before.

Now there seems to be a little less detonation but Im still worried Im doing damage.

Do you think I need a colder plug? I have been thinking about trying a 9. Maybe bigger pump jets? Anything else I could try?

Thanks, Damo

[Jim Ratto]

check your float level. No matter how much main jet (or idle) you throw at it, if your float level is too low, the static fuel level will be too low in emulsion tube wells, and it will run lean.
Otherwise, your settings look good.
Once you get it sorted- try an F4 emulsion tube, then hang on!

Jim

[Jim Ratto]

You can also tune the MSD distributor to slow rate of advance, by changin springs. Normally, I would use a fast rate of advance, but slowing it down, may help

Also, do you know which accelerator exhaust jet (in bottom of float bowl) you currently have? If they are the "open" type, get 00 (closed) ones, which will really richen up acceleration.

Jim

[damo67bug]

Cheers Jim I'll try and get a tool to measure the floats as I bought these of someone and have no history if they have been set. Also the jet in the float bowl is just a standard one would this be a closed one.

[richie]

What country are you in?  if Europe why not use the 99octane fuel?  that's a decent amount of compression and the higher octane will give you a bigger margin of safety, I would go up on idle jets as well straight away and one size on mains to start.

I don't think you need ngk9s with that set up.

What gearbox ratios do you have? to tall and you will be putting more load on it at low rpm.   Can you put a picture up of the engine bay?  is all the tin fitted and sealed up well?

cheers Richie

[damo67bug]

I live in England dude v power seems to be the highest octane over here as I know of which is 97 Ron. I have all tin ware in how it should should. Can't seem to upload a picture at the moment mate.

[Lids]

v power nitro+ is 99 ron

[JS]

I think the best thing you can do is get your car on a rolling dyno. You might even find some extra HP as an added bonus.

Don´t think you need colder plugs, I run 12,5:1 compression with 98 octane and have NGK 7´s.

[damo67bug]

What motor you running js and what power

[JS]

2275cc, 266hp(DIN).