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Discussion Starter #1
Hey all, im running a 552 ci stroker motor in my FED here in the UK and im after some advice. At the weekend I was getting a fair launch (1.27 60 ft) and run consistantly in the 8.7's at around 147 mph. However it does feel that the car really noses over in the second half of the track. She's running 5.5's in the 1/8th at around 123mph.

The combination is as follows:

Stock block, 4.5 stroke crank, 60 thou over flat tops giving 13.76 : 1 compression with stock unported FRPP SCJ's.

Reed Roller Cam
Running duration : in 303 ex 310
Valve lift : in .702 ex .721 @1.73 RR
Duration @ .050 tappet height : in 269 ex 274
lobe centers : 110

Edelbrock Victor
1800 CFM Rons Flying Toilet Methanol Injection System

Were running a glide with a low first gear, launching on the transbrake at 5000 rpm. I believe the combination i have currently is all done in terms of power by 6300 rpm.

Im thinking that getting the heads ported would help largely with stopping her from nosing over, as it seems like the heads are a restriction to how high she wants to rev. Also looking to change from a collector header to zoomie's for next season. Cant remember the reason right now, but we started her without the headers attached in the pits during this season and she seemed a lot more responsive and also a lot smoother, so im wondering if the current headers are acting as a restriction as well.

We ran an 8.59 as well during the year, i think the reason we were slower at the weekend is that weve started bending the wheelie bars on launch, which i think is costing us 0.05+ to 60 ft. Im hoping if we can sort out these restrictions that we can run down into the low 8/hight 7.9 at 160-165mph (we were running 150-155 earlier this year). Does this seem realistic?
 

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IMO,It seems like the 1/4 mile mph is low.Is the 1/8 mile mph lower than ealier in the year if so maybe valve springs getting weak?

Later Mark.
 

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Discussion Starter #3
Hi, this year has been our first real solid year with this combination and we dont have a lot of track time to look at. Realistically we have 2 meetings worth of data at 2 different tracks, plus this weekend. We had a fresh engine and box at the start of this season, the new engine destroyed our new box and left us out for a while. Our first meeting back and we were pulling large wheelie's but ran a new PB of 8.68 @ 155mph with a 1.298 60 ft. 1/8mph was 126.34 @ 5.544. We fitted the car with wheelie bars for the next round, where we ran a best of 8.5992 @ 151.58 mph - 1/8 was 5.4252 @ 125.88 MPH. This was on a track prepped for Top Fuel, Pro mod etc.

This weekend's passes was on a very cold track, I dont have any data as to track temperature but I know we were struggling for traction and the car was moving around more from around 330ft. The car was wheelieing heavily though at this meeting, we had the wheelie bars in place, and i believe the height was set the same as at the previous meeting, but the car kept bending the wheelie bars on launch, so we will be looking to improve those for next season. However all year i have felt that the car was nosing over at the top end, and thought that the speed was low compared to the et, which makes me think that there is a bunch more to come when we sort that out.

To give you an idea about how hard the wheelies were ill post up a couple of pictures.







The last picture shows that the front wheels are still in the air at the point that i shift, which is after 60ft, so the 60ft time may be with the back wheels.

I think at the moment the heads / exhaust are restricting the amount of rpm we are turning and killing the top end mph. As i say the heads are unported out of the box SCJ's, and i think they are restricting the motor from around 6000 rpm's. I was always trying to keep the motor from wanting to spin more than 6500 rpm's through the traps to keep attrition low, but im wondering if she's not spinning enough. 151-154 mph is 5900-6000 rpm's plus convertor slippage.
 

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Discussion Starter #6
Thanks :)

Theres no high speed lean-out on her, and i think the pump is the 0-1/2 black gear pump, but i might need to double check that if i can find out the documentation.
 

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Discussion Starter #9
This is going to sound real bad, but were not 100% sure. Unfortunately weve spun the outer on our SFI balancer (2nd one now!) so our timing mark is no longer reliable. Its set to around 40 degree's of advance. Weve tried advancing and retarding and both seem to lead to a loss of performance.
 

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Id try turning the timing to around 32 or 34 i had the same problem and we backed my
timing down and solved the problem... it picked my car 2 tenths and i was running 38 degrees... ps i also stepped down to colder plug..
 
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