Stroker not running well, what next?- updated with fix

[ugly2u]

I've been having problems with the engine running poorly at the track. I tried rejetting, replaced metering rods/springs and re curved the MSD with new bushings and springs, but it's not getting better. Mostly the problems happen at WOT, and it runs ok on the street.

Running at the track, AFR pegs over 17 at WOT and the engine stumbles badly. On the highway, doing 60 and flooring it, It is not as bad.

What should I try next? I'm in Colorado at 5300'. Larger secondary jet? More fuel PSI? New carb? New car?  

My combo:
Stroked 440
Edelbrock 60929 heads
Lunati 60303: Duration 268/276, Lift .494/.513
Torker II intake
Edelbrock Thunder series AVS 18134 (changed jets and needles to adjust 10% for altitude, set the float to 7/16")
MSD Pro billet 30 deg initial, 35 total (welded advance hole, tuned for max vacuum at idle 12-13")
MSD 6AL
4.5-5 PSI from stock style fuel pump, showing on an inline cheapo fuel pressure gauge
HP manifold
3" exhaust
727/3.23 sure grip

What should I expect for ETs/ trap speed from this combo if it's running right? I have one more day at the track this season to test and tune, next Wednesday. Share your thoughts please.

Thanks!

[firefighter3931]

If the AFR is pegging that lean then there is your problem. It's either the fuel pump or carb. 

I'm thinking the fuel pump is the primary culprit in your super lean WOT AFR's 


Ron

[ugly2u]

Seems logical.

Is 4.5-5 psi normal from the stock pump? I have read here that the push rod can wear down, but I can't find a replacement to check it. Anyone know the correct length? And where to get a replacement? If I add an electric pump and keep the stock in place, would that boost PSI? Or should I add electric and ditch the stock? 

Thanks Ron, and other who make DC a great resource on the web!

[MSRacing89]

I have to agree that there are some fuel delivery issues.  I am hoping you are running atleast some 3/8" lines from the tank?

[Back N Black]

Seems logical.

Is 4.5-5 psi normal from the stock pump? I have read here that the push rod can wear down, but I can't find a replacement to check it. Anyone know the correct length? And where to get a replacement? If I add an electric pump and keep the stock in place, would that boost PSI? Or should I add electric and ditch the stock? 

Thanks Ron, and other who make DC a great resource on the web!

The push rod length is 3.25 inches.

[firefighter3931]

The stock pump will be inadequate for a stroker inmo. The Carter 120gph HV mechanical worked well on my old 446 that made 535hp/540tq and the 4100 Black Pig was running 11.60's @116mph at that time. I'm thinking the fuel pressure is a bit low....i'd like to see a solid 6-7 psi running down the track at WOT. 

As mentioned above, the stock length for the pushrod is 3 1/4 inches. Mancini Racing sells replacements and also carries a nice bronze tipped fuel pump rod. 


Ron

[ugly2u]

Thanks everyone for the feedback!

Electric fuel pump in hand, will install this weekend and update track times after next weeks run! 

[Kern Dog]

I'm surprised to see anyone run an Edelbrock craburetor on a stroked 440. Even an 850 is inadequate for anything over 5000 rpms. A Holley or Demon carb is the way to go for  power and low ETs. Nobody every claimed they made their engines run lean!

[myk]

I'm surprised to see anyone run an Edelbrock craburetor on a stroked 440. Even an 850 is inadequate for anything over 5000 rpms. A Holley or Demon carb is the way to go for  power and low ETs. Nobody every claimed they made their engines run lean!

I never knew about the 'Eddy 'carbs running rich at idle and then lean at throttle until I had personal experience with it.  What can I say?  When I was shopping for a new 'carb, Edelbrock had the biggest pictures in the Summit catalog...

'OP I can't wait to see how your car does with an electric fuel pump...

[elacruze]

 

[c00nhunterjoe]

While an 850 is too small for a stroker engine, if jetted properly it will still run a clean mixture, just not at its max potential. Same goes with cam choice....his choice of cam is pretty small. That engi e should have tons of grunt off the line but run into a brick wall at 4500

[Musicman]

The stock pump will be inadequate for a stroker inmo. The Carter 120gph HV mechanical worked well on my old 446 that made 535hp/540tq and the 4100 Black Pig was running 11.60's @116mph at that time. I'm thinking the fuel pressure is a bit low....i'd like to see a solid 6-7 psi running down the track at WOT. 

As mentioned above, the stock length for the pushrod is 3 1/4 inches. Mancini Racing sells replacements and also carries a nice bronze tipped fuel pump rod. 


Ron

As Ron stated, you're fuel bowl is drying up at WOT on the track.... supply & demand...
Rapid acceleration also leads to higher G forces which make it harder for a stock pump to get fuel into the carburetor fast enough to keep up with the demand.

[ugly2u]

Okay, so it ran better. But not what I hoped for...electric pump installed and it still shows 4 psi. Changed the pressure gauge and the new one reads 6-7 psi; the old gauge was busted. Also, when I shut off the electric pump to test the mechanical pump, its only pushing 2 psi, not 4 psi that was showing on the broken old gauge.

I guess I should also pull the mechanical pump and check the push rod is not destroyed.

13.44 sec was my best ET tonight. AFR was low to mid 13 at WOT and high 12 to low 13 at cruise on our way to the track. Seemed to run much better since installing the electric fuel pump. I was expecting better ET from what I read here about stroker power. Aside from that, my younger brother (28 yrs) beat me (47 yrs) with a 13.1 in his BMW; also his best ET. Not Okay!  

The car, with my buddy and I weighed 4200 lbs.

Seems like I still have more work to do? Wrong carb? Wrong cam for max HP? Pinon snubber? Torque boxes? Slicks not street tires? What else? I have several months to work on it.

Any recommendations to boost track performance without killing street driving/fuel consumption (95% of its use)? I know HP and fuel economy are mutually exclusive.

[firefighter3931]

Post up a time slip so we can see what it's doing at all the incrementals ; 60ft/660ft/1320ft ect....i'd be interested to see what the MPH numbers look like at those points. 

You have a 4000lb car with mild gearing running at 5000+feet....it's not really that bad considering all the handicaps. At sea level you would be in the high 12's for sure.

Your engine is way undercammed and it's hitting the wall at 5000rpm max. You definately need more cam, a better carb and a set of headers. The stock manifolds are choking that engine bigtime ! 

Maybe a rundown of the engine would help ; displacement, static compression ratio etc....

With the right tweaks and some tuning you should be able to run a high 11 no problem....even at your elevation 


Ron

[ugly2u]

Here is the time slip, but it does not show speed at each interval, just time.

I'm not sure of all the specs, but the build sheet says 493 Cubic inch. Deck clearance is .008. Mahle piston 1.5 1.5 3-0 (doesn't mean much to me). Eagle crank and rod 4.15 stroke.

It was built to run pump gas.

What do you think would be a better combo for the cam, carb, and headers? Does the cam come out without pulling the engine? I guess I have more reading to do... Thanks for taking a look at this.

[firefighter3931]

The timeslip isn't showing anything abnormal ; the 1/8th mile ET is in line with the 1/4 mile ET. 

The 60ft could be better. Was the car spinning the tires off the line ? What stall are you running ? Tire size ? Raceweight ? What is the shift rpm ?

Basicly, it's just down on power due to the engine combination....the MPH tells us how much power it's making. The cam is too small, the carb is on the small side and the exhaust manifold is choking it.

Carb ; 850dp
Headers ; 17/8 or 2in primary tube
Cam ; something with at least 10* more duration@.050

What is the static compression ratio ? Are the pistons flat tops or dished ?

Yes, the cam can be swapped in the car.....no need to pull the engine   



Ron

[myk]

I was wondering about traction issues also...

[69wannabe]

Sounds like a good combo but the edelbrock carbs are really not performance carbs. I'd go with a proform or holley 850 double pumper carb and go up a size with the cam!!! A good street cam for that engine should be around 240 degrees @ 50 or 248 degrees @ 50 with a good 3000 stall converter. Yes the 60 foot time was lower so its either spinning alot or dragging out of the hole. A good 3.91 or 4.11 gear should be good in that car since it's running a 1/4 mile. Had a stock stroked 440 in a 70 cuda running 7.90's in an 1/8 and it had one of those 114 centerline mopar cams in it which could of been alot better if we would have had any experiance but we were learning for the most part. It would spray into the mid 7's which was pretty good for our first street/strip car. 

[myk]

Sounds like a good combo but the edelbrock carbs are really not performance carbs.

Is that truly the case?  With all things equal, if there are 'carbs out there that are undeniably better for us than 'Eddy 'carbs then I just might have to get rid of mine...

[69wannabe]

Sounds like a good combo but the edelbrock carbs are really not performance carbs.

Is that truly the case?  With all things equal, if there are 'carbs out there that are undeniably better for us than 'Eddy 'carbs then I just might have to get rid of mine...

I have ran the eldebrock carbs more than several times just because they resemble what would have came on an original mopar. I had a couple of 600's that were pretty good carbs and a 650 AVS on a 383 I was running at one time and a buddy of mine needed a holley 750 DP rebuilt so I built the carb for him and stuck it on my 383 just to tune it in and make sure it ran good. Man what a difference that holley made!!!! It completely changed the performance of the engine so I had to trade my buddy out of that carb!! When I swapped in the 440 I stuck that 750 DP on there and never looked back! After that I haven't looked at another edelbrock carb. The eddy carbs are good for driveability and very mild engines I suppose. I built a 383 for a friend of mine which was all pretty much stock with a comp Xtreme 268 cam and an eddy performer intake and 600 carb and it ran great!! Just depends on the application and or your engine fuel demands. A good 440 loves a good 750 holley tho!!!!

[2Luke2]

Where abouts in Colorado are you if you don't mind me asking? Lisa and I are in Colorado Springs. Our stroker is running well enough to attempt to break our transmission, but it still has some bugs to be worked out. We are hoping the drop the tranny this weekend and rebuild it in the next couple of weeks. Ron along with a lot of other good folks here have been very kind to help us through them. We're glad to hear yours is running a bit better now with the new pump.