was the first motor ever dyno'd? could that motor possibly have been an overachiever?

how much larger is the camshaft in the new motor vs. the old? it possible you need a converter and gear change?

I’d say step one should def be make sure timing is correct, you’re getting wot, etc....... the basics.

Pull all plugs and do a cranking compression test on all cyls.

If it all checks out good, head to the chassis dyno for a few pulls.

When it had that valve float at 5500, it had a different intake on it, correct?
What was the speed then?

I’ll just throw this out there as another possibility ........ the converter might be going away.

110MPH @ 3600# - 375HP at the wheels. 104 - 325. Down 50HP. Also 104MPH is 12.50 - 12.70HP A good 60' would be 1.77 - 1.80.

Lean at WOT would be where I would start. Verify the secondaries are in fact opening.

I appreciate everyone's feedback!

I definitely have a lot of things to look at.

To begin with, I was really looking to the KISS stuff first, although, the more in-depth stuff may be needed at some point if the stupid stuff is good.

I'll reverify some things and go from there.

To clarify, I wanted to dyno the engine with exactly what it was going to be run with, the dyno shop wanted to run the engine with the headers, it was not my call. I did not say that I had good data, what I said is that all data is good, the more you have, the better.

Dwayne, you bring up something I was thinking about. The main reason I wanted to go to the track before the end of the year is, I wanted a baseline before having a new convertor built. The converter in the car is 30 years old and has never been freshened. I've thought for years that there were some gains to be had with a better converter, that was set up for the car. What are the symptoms of a converter going away?

There are definitely more questions I need to answer from above. I'll keep adding more as I have time; on my lunch break right now and checking in quickly.

^^This, plus I would run a leakdown on the engine.

Well, one of them is the car slows down.

If everything else checks out fine, and since you were considering something different....... it might be worth trying something else.

I’d def have a proper cranking compression test near the top of the list.
Engine warm, all plugs out, wot, battery charger hooked up.
Test at 4 pumps, and max pressure(like 8 pumps).

I used to bracket race a 66 dart with a 3602bbl engine with nothing but a thermoquad and manifold swapped on it, I got it very consistent and it was an over achiever combo, low geared 904 and 2.94 gears, finnaly decided to get a bigger cam XE268 and matching springs and stuff and it slowed down a ton 60ft, MPH and ET all were way down even though it actually pulled way harder and way higher RPM, eventually I put in 3.92 gears and it became way faster and way less consistent. Just because you are running slower does not mean the engine is not making more power, it could just be that you are not using it all. With that big of a cam and low compression you are going to have a very soft bottom end and you probably will not catch your old combo till you make matching changes to the rest of the combo. And for the people who say MPH is HP.... that is only true if your car is close to set up right, try running your car launching in 3rd instead of 1st and see how much slower your MPH is at the end of the track. Also the engine wanting to turn higher RPM because of the bigger cam means the manifolds are going to be a much bigger restriction than they were on the lower RPM combo.

I'd move the timing and see what happens. I broke a converter 2 times 2 cars in the last year. Car $1 11.07, 12.26 3 passes later. Car #2 9.18 to 10.12 on the next next pass. Car number 1 with the wrong converter 11.70@122, swapped a week later 11.05@122.
Doug

Timing marks verified correct?

This.

Plus the questions asked in the second post: cranking cylinder pressure, actual cam 0.050" durations, LSA and ICL. Is it a solid or hydraulic?

Although there has been a lot of good comments as to what could be the problem, I'm guessing it's the cam and lack of cylinder pressure.

that cam with a 110lsa and hydraulic tappet would just up the misery index. if so the intake valve may be closing close to 80 degrees ABDC, pretty late. cylinder pressure may be in the toilet. know my 9.3:1 cast manifold engine would just roll over and die with any cam close to that. but, in fairness there could be some fuel delivery issues too. i know that a 5-6lb fuel pump won't do 5-6lbs at WOT; probably closer to 2lbs. of course a complete run down on before and after of the engine combo would go a long way to finding solutions.

I've seen zero pressure from the 1000 to the 1/4-mile finish line many times with street Hemi motors
They didn't miss or burnup spark plugs but they went quicker and faster with the better Carter NASCAR three valve mechanical race pumps
All things wrong with a drag race car can be fix

The engine dynoed at 460hp with headers.
If we say the headers were worth 35hp, that puts it at 425hp, corrected.

If there is another 15% lost in weather and installation in the car, it’s juat over 360hp as installed.

The moroso chart shows 108.5mph for 360hp and 3650lbs.

Something is way off.

I think so too, Dwayne.

I just haven't had time to start checking things out. Hopefully next weekend I can get to checking some things but, really, most will occur next year.

I got most of my cars packed up for the Winter today. I have two more to wash.

My Wife's car has been killing me lately. Fixed the exhaust and changed the oil recently. Was driving it yesterday and a pad was hanging up on the driver rear. Looked today and the hub is junk, and the brakes could use changed. So, next weekend on this.

A hub on my Winter beater needs changed too, along with an oil change.

I did call PTC earlier this week and ordered a new converter.

I'll get the Road Runner sorted out at some point. Really just ready to relax soon. Been a busy year.

What did you get for a converter?

How about a quick rundown of a couple of configurations you’ve had.......
Cam, gears, tires, intake, exhaust, carb, etc......along with the best ET & speed.

-the combo prior to the KG heads

-the first combo with the KG heads

What cam went 12.25? Exhaust manifolds or headers? And what mufflers?

What are the full cam specs now, and what mufflers are you running? What is the displacement?

250* at .050 with pretty much any ICL or LSA is probably too much for exhaust manifolds, let alone in a 9.3:1 engine. That does not sound like a cam spec’d for manifolds at all.

I think your exhaust manifolds and the turbo mufflers you’re probably running (especially if they are Hush Thrush) are killing a lot more power than you think. And the 250* cam put a big hole in the torque curve and you’re hitting your converter way less than the old combo did, which is exacerbating the issue.

The short block, minus the cam is the same it's been in all combos. A 400 based 470, 440 source rotating assembly. 9.35:1 compression.

The first combo included a comp hydraulic flat tappet (.488/.491 lift, 230/236 @.050, 110 LSA). I had a performer RPM intake, Hooker 1/78 long tubes with a 3" collector, compression bent exhaust with flow master 2 chamber mufflers, 4.10 gear, an old super street fighter converter, an MSD billet distributor, a set of big valve 213 heads and a Holley 850 street hp. I ran some 28x10.50 Sportsman Pros back then. The best I ran in this configuration was a 12.33.

I switched to a 3.73 gear and a custom curved vacuum advanced distributor and ran a best of 12.25.

I threw the exhaust manifolds on the car along with a mandrel bent tti exhaust system with Dynomax Super Turbos and went to the track once with this change and ran a 12.48. The track was marginal that day and I think I could have run a little better if I would have taken it to the track a few more times.

I then switched to some K&G ported 906's, a dp4b intake and some American Racer L60's, ran at the track one weekend and ran a best of 12.50. The weather was a little hotter that day then what it is when I normally run but, not super hot (low 80's). The big issue, which prompted the cam swap, is that I ran into valve float with the valve springs on the new heads. I'd heard for years how bad the XE series cams where with this but, never experienced it myself, until then.

I had a new solid flat tappet cam ground. Long story short, when swapping the cam, I found some bad cam bearings so, back to the machine shop it went. Upon further inspection, they discovered that the line bore was not done correctly on the mains, so; it this was corrected and the whole engine was freshened.

I ported a 301 intake and threw it on and switched to an Edelbrock 800 Thunder series carb with this iteration.

Dwayne spec'd the new cam for this combination, out of respect for him, I didn't post up the exact specs of the new cam. If he's okay with me posting them, I'll gladly share them.

was the "301" intake and Edelbrock 800 carb on the motor on the dyno??

looks like your TCI converter is supposed to be about 1500rpm higher than stock. is it flashing to 3500rpm??

IMO i wouldn't use that xe274 cam with stock manifolds, and definitely wouldn't use the 250@.50" with manifolds. that being said losing about .25 of a second with manifolds vs the headers does make some sense. with the "250" cam put the headers back on. you need the separation of the exhaust pulses plus the have more volume. i also i would take a very serious look at fuel delivery. dumb things can happen between the tank and carb; cracked hose, pump push rod, inadequate pump, etc. my experience with those 800 carbs has been they are more likely to be rich than lean as they come out of the box.