498" Drag Race Fuel / Timing Help

[jcooper]

This year we put together a bigger engine and have been running into some issues not seen in prior 400 ci engine combinations.

498 ci engine with trick flow heads, 12.8:1 compression, custom Flat tappet cam 258/268 @ .050' with .649"/679" lift, trick flow track heat intake with 1050 quick fuel carb, 110 octane race fuel

Engine is ran in a rear engine dragster with powerglide and with driver is 1800lbs. First weekend out we struggled to get the car to go down the track fighting horrible tire shake, so bad it kicked the power off one pass. This past weekend we did find a tolerable tire pressure to get the car to go down the track with a best 1/8 mile time of 5.19 @ 128mph shifting at 6,300 rpm. Engine seems to be running very strong but would like to get input on the two timing/fuel questions below. It would be great to have a test day to get 6-8 passes to test variables but it seems most tracks barely give you 1-2 test passes so looking for the groups help to dial in the combination so we can get back to racing and winning!

1. Current timing is at 34 degrees and that is what our old smaller FE engine seemed to like but not sure if that is the right number for this bigger ci engine?

2. Spark plugs we are running are AR3910. The procelain on all plugs seems to be yellow. We have tried adding fuel but only seems to slow car down so assume it is on rich side but not sure what is causing the yellow color or what the cure would be?

Thank you in advance for any help you are able to provide!

[blykins]

Usually a yellow or green tint on the porcelain needs the plug is too hot.  Can you post pics?

Timing is probably close, but you can read a plug to see if you are close.  Ultimately it will be the setting where the car runs the quickest.

[jcooper]

I attached a spark plug photo of cylinder 1(left pic) and 4(right pic), hope it works. We run the AR3910 plug which is a 3 on the heat scale, can you suggest a colder plug?

First pass yesterday the porcelain was bright yellow and top ring was clean so increased jets 2 front and back. 2nd pass did not look much different so bumped up jets again. car slowed slightly but altitude was increasing all day. As stated before carb is a QF 1050 with last pass having 97 jets Front and Back(plugged power valve in front and back).

Thanks for your help

[blykins]

On my computer and phone it just looks like a natural tan. 

By the looks of the threads on the plug though, it looks like they're getting a lot of heat.