How Much More Timing is needed if the "Blue Line" is 1/3 to 1/2 Down the Strap???

I did try 32 in adrl race in la way back. those same heads. on suggestion of brad and his son in law because looking at my racepack they saw something ask did I have a different rear gear.it lasted to 330 but then ruined a lot of new bottom end parts and a burned front end.they asked me how much was left in the tune up.so hope that helps.no more advise other than tread light with timing,good luck .

 

What are the cc's on those Venny heads

 

Correct, I have 173cc Veney fuel head, 4.310 bore x 4.5 stroke, and 10.4 to 1 compression.

 

Thanks mike and Scott. cj

 

i have run the 2.500 veney heads for years and while you can go above 30 degrees, you don't need too... trust me. i ran over a tone of stuff with a screw ant 32 degrees.. what happens is the more timing you run , the smaller window you have for detonation to come into play. max i would run when you put the timing back in would be 30 degrees but for no longer than 3 seconds. then pull 2 out of it and run it through the lights at 28. the fastest mph I ever ran with the screw and a funny car was with 28 and the motor was very happy and safe. can't argue with that.

 

What about compression ratio how does that affect max timing. Lets say from 10.5.1 too 11.5.1

 

i'm running just under 12 to 1 with a roots right now. when I ran a screw it was about 10.8 . still run low timing because with a 44 amp mag I still feel 28 is about all you need.. and knock on wood I haven't been tearing stuff up from lean, or detonation so why risk a couple degrees .

 

the c blower is different.not even close

 

Can you explane what effect the chamber size VS ignition timing?If you run a TA/FC engine combo 96cc chanber ,PSI D 92% than you can run more timing on the start line than 27°,but how much you can advanced??

 

As far as I'm concerned the dyno is the best and quickest way to set the ignition timing.

It appears to me ignition timing that makes the most power is not going to hurt parts.

I am trying to dyno test if the different compressions take different timing but its difficult to change 1 thing at a time. Different head gasket changes the squish, different domes or chambers and you have a different shape.

 

Winter Work So Far

Lots of work has happened so far, and more to go this winter.

Rings and uppers on rods replaced. TDC checked and rechecked, will work on the 30 degrees and rotor phasing.

Transmission. Lost 10 lbs. with new sheet aluminum pan and trimming bolts.

Rear. Lost 12.5 lbs changing from iron to aluminum center section and went from 4.29 gears to 4.86 for 1/8 mile. I will get 4.56 for 1/4 when that happens.

Batteries. Working on the total weight loss, (will be close to 100 lbs). The batteries what were in the car were pretty much ballast for the old 3200 lb. requirement. 84 and 13lbs. plus two cases. now two 4.8 lb batteries in their place and will working on lighter wiring.

Every bolt front to back evaluated and cut to proper length (about 2/3s done).

Lightweight steering wheel and extension (Merry Christmas!).

Some titanium where it was simple and cheap.

Steel rear bumper replaced with fiberglass.

Metal rear wing struts replaced with CF tubes.

Lost 5 pounds myself....

Any other ideas to lose weight?

Thanks!!

 

Lmao good job Scott

 

Weight

Aluminum dzus fasteners are great and when done over the entire car will save some weight, I use the allen key ones.

I am doing my dragster right now and using the following system to get the most weight out. I am weighing all parts and figuring out what lightweight replacements would be. I am then doing the math and figuring out cost per 1 lb saved. I have no weight minimum so I do not have a target weight just a budget to figure out.

Some general advice since I don't know the car.

Anything that is mild steel (With the exception of bolts) replace first as that is generally where the most weight is (Generally) and replace with appropriate materials for the given part such as chromoly, fiberglass, carbon, magnesium, or titanium. This sounds like it is a real car that has been turned into a race car, I would start with bumpers, hood, doors, deck lid, glass to lexan if it isn't already. If you have heavy bolts like the 4 big clutch can bolts those are generally worth going to titanium and save some weight.

Next anything that is aluminum sheet can go to carbon except the firewall and I think drivers floor, those could be replaced with titanium

Nylock jam nuts on non heavy clamping bolts, since the nut is just keeping the bolt (Which is doing all the work in place)

Don't be afraid to look at odd areas, I have a friend on here who had an adapter plate and a motor plate, he didn't think he would save a lb, it saved 2 or 4 lbs (Can't remember) when he was done lightening it

Rotating weight is twice as important, wheels, pulleys, driveshaft, converter/clutch.

As an guestimate most parts weight can be cut by aprox half by replacing with a suitable lightweight material, mild steel to moly, moly to ti, steel to fiberglass, fiberglass to carbon, aluminum to mag.


I will be posting weights and materials before and after for the individual parts of my dragster for a reference when we start getting the new parts in if it helps anyone. I have always wondered and never seen anyone do it so I will go for it. Not sure how I'm going to weigh the chassis though using my bathroom scale....

Best wishes Scott,
Trevor Sherwood

 

Lots of good ideas there...

Thanks Trevor,

Lots of good ideas there. Midplate is off the table until the motor comes out (hopefully it will make it through 2015), but the front plate is extreme overkill, will look at making it look like the front plates I see on the fuel and funny cars.

I'll run front to back again an see what I can come up with.

Thanks for the ideas.

 

I got some weight off my car from tire and wheel combo. minus 20.4lbs, and then a 5lb air bottle instead of a 10lb bottle lost some more, and finally the biggest weight saving for me was a carbon fiber wheelie bar. over 20 lbs saved here. also fuel load.

 

How do they last?

How well do C/F wheelie bars last?

 

No worries Scott,

I don't know the life of the carbon bars but I figure it can't be as long as the metal bars because I have seen lots of pro mods with Carbon lower bars and a Ti upper, Seems like the upper takes the beating. I am looking at all Ti on my wheely bars since my shorty bars (approx 3 ft) weigh 11.5 lbs and they are not braced at all.

Also just found out my sheet aluminum dragster seat was 5 lbs, the carbon replacement should be about 2 lbs.

Some not essential nuts and bolts can be replaced with aluminum but you have to be extremely careful which bolts you swap out, I am replacing the bolt under my accelerator pedal with aluminum because it doesn't really hold much. Other than that I haven't found any other are n my car I trust to put them. Ti is a better option for strength but I don't recommend them for rear end mounting, axle studs or nuts, wings stands, or front steering parts because of what happens if they sheer.

I will work on getting the weight sheet up and running

Best wishes,
Trevor Sherwood