I think he is going to have to do a whole lot more than degreeing the cam to pick up over 4 tenths. A lot bigger roller cam or a head swap. That is why I mentioned the NOS.Plus with the NOS and timer he could dial in for the hot or good air by adjusting the timer, that would be easier to get to run exactly 10.90 regardless of the air quality.In the index class he has to run as close to 10.90 as possible without breaking out.

I ran a 10.12@130mph in my 2850 pound pump gas Duster two weeks ago in some crappy Pittsburgh Summer air. My Edelbrock heads flow less than his 292cfm heads, my 540-550 solid lifter cam is way smaller than his, and I know I am giving up some ET with a powerglide trans compared to his 904. My 750 holley works fine but I know a bigger carb would be a tad quicker. My 14-32's are WAY over-kill and my 5200 stall is about on par with his. No NOS needed just some test&tunes like he is doing. So do the math and calculate the weight per ET and you will see what can be done. Oh and if you don't think a powerglide is slower than a 904 in a small block car ask a few of our member that tried that combo and QUICKLY went back to a 904.

I am determined to get this thing to go in the 10's on the motor...It has had a cheater plate kit on top of the manifold for the past 2 years and has not been used once- last year the motor croaked before I could, and this year I want to get a 10's pass on the motor before I spray it...A friend of mine who LIVES for spray has been riding me all summer to just spray it, especially now since I still haven't hit 10's. But I refuse to use it to pick up such a small amount- even if it needs better heads or a roller cam, I will do that over the winter to get it into the 10's before I spray it.


I got started on advancing the cam, but unfortunately having the car outside makes me mercy to the dark, so I have everything ready to go for tomorrow for when I get home from work to finish it up (not to mention my nitrous buddy came over unexpectedly and talked my ear off for a couple hours lol). Do I think advancing the cam will make a HUGE difference? maybe, maybe not, gotta try it and see...but if some changes don't get me where I need to be, possibly heads and cam, or just cam over the winter might be what I am looking at. Gotta give Brian at IMM a call and discuss with him about this stuff.

I am definitely looking to put an electric fan on this thing..Next time out im going to pull off the clutch fan for a pass and see what it runs and just get my friend to tow me back as I don't think I will be able to get an electric setup in time for this year (got alot of other stuff going on right now too).

Oh, does anybody have a 904 low gearset they are willing to part with for a reasonable price? lol

To be honest, your goal should be achieavable if the heads are as good at the track as those lofty flow numbers would suggest
I raced( at the time) an all steel completely bone stock bodied 70 Duster. Factory bench seat still installed and I shifted the 727( not a faster 904) off the column.
With roll cage, frame connectors, etc, etc, and my 300 pound butt driving it weighed 3450. Flat factory hood, no scoop then.
416, flat tappet, dinky Tti 1 5/8 to 1 3/4 headers and mild edIdies that went 274 max, per Hensley who stage two ported them. Went 10.74 at almost 124 at almost identical weightas you but without a 904. Would have ran 10.50's swapping out the 727.

Your cam is real small for a 4 inch motor mine was [Email]260@50[/Email] and street able enough to make a 70 mile round trip jaunt to the track and lay down easy 10's through the mufflers.
I would think if those heads are close to being good with a 904 tens should be a piece of cake.
Just my honest
Your going in the right direction with your changes, convertor, and advancing the cam. I have never heard of a 108 cam being installed straight up before, it kills bottom end. Bet it will help you advancing it.
Electric fan and water pump are a free tenth if you want fairly cheap noticeable ET improvement.

It's certainly do-able Matt. Have you scaled the car yet? The cheapest way to go faster is to get the weight out of the car. When you caged it did you weigh the tubing you added? I cut a whole lot of weight out of my car with a set of hole saws and some creative plasma cutting. Tubular bumper supports and trimming down EVERY bolt on the car is how I'm shedding weight.

Steve

Been following this post and looking forward to seeing what effect advancing the cam makes. Did you get it advanced and will you be running the car anytime soon? Hope the changes get you closer to your goal.

Advancing the cam will help the ET, but with those already way too fast (port speed) heads I would guess that the MPH will stay the same or even fall slightly. You don't need a lot more grunt--you need more mid to high rpm pull. I have built many 4" arm SBM's and getting one to hang on past 6000 rpm with iron heads (except W2's) is difficult. Throwing more cam at it won't do a thing--You need more CSA and stable air speeds in those heads and manifold. Just my 2 cents. J.Rob

Hey everyone, so an update is in order.

First thing- I didn't advance the camshaft...I had the timing cover off and was about to, but spoke with Brian at IMM first...He was all for me trying it until I told him that at the track I was running a 6 plug with only 30 degrees of timing and threw in a set of 8's (NGK's) to be able to add 34 degrees safely as the 6's showed light peppering aka good ole detonation. I pulled the intake to make sure there was no oil in the ports and that wasn't the cause of it, and sure enough it wasn't. This didn't make me or him comfortable with the idea of advancing the cam, especially since it would only increase my chances for this motor to detonate. Although I am leaving off a brake, the car is still heavy, and with only 4.10 gears, the motor is seeing alot of load. I didn't want to pay the price for detonation issues, so I opted for now to leave the cam as it is in the motor.

So I have put the timing cover back on, and at Brian's recommendation threw on my eddy air gap manifold from last year....Reason being, Brian has seen them make much more power down low than the victor, and even though this motor will spend all of its time above 5000rpms off the line, the extra torque down low should really help get it 60'ing better. I had already had the manifold too, so it was just gaskets and time which doesn't hurt to try.

I have also tightened the lash up to .011" cold intake and exhaust to help close the intake valve a little earlier and see if it helps with the detonation issue. I am running about 10.4:1 cr with 94 octane gas and .039" quench, but the plugs are showing the motor is not happy. For the next outing im going to throw a fresh set in there and go from there with timing and jetting. Hopefully the car will 60' better, and maybe in the cooler air I will see my 10 second timeslip, but I want this thing to go 10's in the heat.

I don't think a bigger cam would really help me at all at this point- car leaves soft already, and a bigger cam is just going to shift the rpm band up anyways. Im also sourcing a low gear set to throw in the 904 before the next outing, so hopefully I will see some gains there as well.

Either way, over the winter I am going to be looking at my options for possible upgrading in heads/cam and losing some weight from the car. For now though all I can do is make a few small changes at a time and see what they net me.

Tightening up the lash will make the intake close later not earlier.

Your right about advancing the cam, making the detonation issues worse.

If i were you, i'd be happy with a high 10 in cool air and over winter do as Ramm says and stick a decent set of heads on it, then sell your steel heads to help pay for them.
I swapped my old mildly ported 346 heads, with big valves and a torker int, for a victor int and RPM's done by MCH (Rip Jeff ) milled to 76 cc and picked up .7 and 6 mph.
Mick

A car as heavy as yours, with a 4.10 rear/tire set up, should have a low gear set in it.

The stroke will easily eat up any extra RPM drop with the fat TQ band.

Work on the 60's times, which may be helped by the low gear set, there's time there.

30*timing and how are you reading the plugs? did I see you were looking for color of the porcelain? if so you will be tuning forever. color of the porcelain has nothing to due with the tune. other than detecting detonation

here you go

http://www.youtube.com/watch?v=fiMM2S0aADM

WOW, those plugs were ALL wrong. I think you're on the right track and the intake swap will help you keep the 4.10's you love so dearly. The low gear set is a good idea too. You'll at least be knocking on the door next time out.

Hey guys,

I drove the car with the dual plane and tighter lash yesterday for the first time, and I must say there is a very noticeable difference in bottom end torque. I am currently trying to acquire a low gear set locally, and once I get that, I will be going back to the track for testing.

As far as plug reading goes, I basically threw out my own knowledge and listened to a long time racer and friend on reading the plugs...judging by how wrong I was going, im surprised how he hasn't blown his own stuff up!!! lol...That said, I ordered a fresh set of plugs, so next time at the track I will be warming the car up on the old plugs, throw in the new ones, make a pass, and then read and go from there. Im going to start with timing at 30 degrees total which I feel is conservative, then read the plugs and go from there.

As for the detonation issue, im wondering if the gasoline I pumped into my jerry cans was a true 94 octane as I really don't think I should have been getting detonation with only 30 degrees of timing, 94 octane gasoline, .039" quench and 10.5:1 cr...but who knows, maybe I am on the ragged edge for pump gas as it is right now.

All I know is that over the winter for sure this motor will definitely be seeing some changes. What those will be as of yet I do not know, but I want this fat pig to go 10.9999999999 in the heat! Not on a "good" day