[MikeN]

I went to the track Sunday with a new combo, and was disappointed with a best of 14.23 at 94.5mph. I'm thinking this combo should run about 13.50 at 100mph, so I dug in last night to begin troubleshooting. Combo is a 355 with flattops, AFR180 heads with 68cc chambers, and a Comp XS262 solid flat tappet cam. Cam specs 224/230 at .050, lift .477/.488.

Compression checked out between 170-175 psi for all 8 cylinders. That's pretty good for a 9:1 motor, correct?

I guess I just need to sort out the carb and ignition. The car was intermittently cutting out on the way home from the track, so I guess I have a little electrical gremlin to track down. The plugs (Champion RC9YC) were pretty fouled to be so new, so I think I'll try one step hotter. Adding to the mystery, when I got around to the passenger side of the engine while removing plugs, I noticed the wire was off of the electric choke on my Holley. Was the car slow (and plugs fouled) because the freaking choke was partially closed? I don't know...I'm not entirely convinced it was the choke, because the idle wasn't high or anything, but I hate to experiment with sparkplugs or carb calibration when it could have been the choke.

Isn't drag racing fun?

 

[blazerbob]

Yes, thats some good compression you have there. Think you cutting out is due to choke malfunction which is fouling your plugs, nothing you haven't already figured out! I would expect 13's, cam may be on small side. What gears and compression? Good luck sorting out the tuning of your engine!

 

[MikeN]

I calculate the static compression around 9.4:1, 3.42 gears, 2400 stall

 

[mr 4 speed]

Mike,sounds like the choke was goofing on you for sure.How does it run with a new set of plugs?

 

[MikeN]

Originally posted by mr 4 speed:
Mike,sounds like the choke was goofing on you for sure.How does it run with a new set of plugs?

Just bought new plugs on my lunch hour, hopefully I can test drive tonight or tomorrow.

 

[BillsCamino]

Mike,
Could the choke possibly be drawn semi-closed under WOT?
You going to Commerce this Saturday?

 

[MikeN]

Originally posted by BillsCamino:
Mike,
Could the choke possibly be drawn semi-closed under WOT?
You going to Commerce this Saturday?

That's what I was thinking. Trouble is, I'm not totally sure the choke wire was off the whole time.

Not sure about Commerce, between working long hours and doing Super Chevy last weekend, I'm a little backed up on chores at the house

 

[Bob West]

Why hotter plugs? why not smaller jets? In a performance application you want a little colder plug