Technical Rebuilt 302 has no get up! Help.

Did you replace the valve springs with larger dia?. Ran into one that rockers were opening valves early by hitting retainers. $50 bench grinder and it was a screamer.

 

Based on all the feedback the glaringly obvious item is the gear ratio. You have to change that first.
I wouldn't change the cam yet, until you have some sort of decent gear ratio - 4.11 or 4.30. With an OD tranny, your gear ratio is off the charts wrong.
1) Fix gear ratio
2) diagnose how the engine is running. Check compression, change to manifold vacuum, check spark advance curve, check exhaust temps, read the plugs.

Did you really put a flat tappet cam in a 1989 Mustang roller block? That Summit cam is a flat tappet cam, the stock cam in an 89 Mustang 5.0 is a hydraulic roller with .444" lift and a good bit of low end grunt. I'd never, ever put a flat tappet cam in a roller block. Rollers are more efficient, more durable etc. Does bring up the question of compatibility with the springs in your aftermarket heads - what spring package?

If, and only if, you've done everything you can to tune the existing combo to a high state and it's still a dog with 4.11 or 4.30 gears...then consider switching back to the original cam and or a higher stall convertor.

Some random facts about stock 89 5.0 engines that might help -
Stock E7TE heads flow poorly, have 62cc chambers
With about a 5cc dish piston the engines have a claimed 9:1 CR more like 8.8:1 real world
Stock roller cam has 266* adv duration, 210* @. 050" and .444" Valve Lift and 115 LSA 1.6:1 rocker ratio

Oh, and, one thing - fix the gear ratio.

 

If it were me I’d make sure my intake was matched to my cam, something that hasn’t been addressed yet. Then call TCI and get a 3,000 stall and put some gears in the back and play hot rod

 

You don’t say if you’re using headers or not.

 

Has anyone mentioned cam and gears?

 

34 5W Paul asks if you’re running a flat tappet cam ? Are using roller lifters? Aahhh ? IDK
Maybe back to firing order??? The possibilities are almost infinite
Dan

 

2nd build always goes better....

 

I honestly have a funny feeling it might not be a cut and dried case of the cam being too big. Cuz no matter the gears, no matter the weight of the car, no matter the torque converter stall speed... I'm thinking that a well-built overhead valve V8 should pull pretty hard at least in the higher RPM range, even with an inappropriately large cam.
Might take some hands on detective work that we can't do here.

 

Hmmm weak valve springs, maybe pushrod length……. I never would have gone with a flat tappet cam come hell or high water. Something to think about are the heads set up for pedestal rockers or are they studded. That would throw the geometry out on the valve train by mixing the two. I’ve run solid rollers in the late model SBF and boy do they pop with 12:1 compression but you have to measure for the pushrods.

 

New distributor? Roller motors have longer push rods did you check length

 

Actually shorter length due to the longer over all length of the roller lifter....

 

Pushrod length needs checked. Could explain things.

 

"I build 'em twice, to make 'em nice."

 

There is about 3/4" difference in pushrod lengths between flat tappet and roller pushrods. Could you even get enough adjustment to get the engine to run?

 

My heads came assembled.
Shorty headers
Longer pushrods, the roller on rockers are riding center of valve stem.
Flat Tappet cam I already had, so I used it.

4:11 gears are next. I’m going to try that first and see what happens, I need to change the rear gear anyway!

 

Rear gear - 2:47 or 2:73

Yikes there's a good part of the problem, 2:47 ??

 

Do one thing at a time !
Gears is a good starting point.
Before you rip the engine apart , give it a compression check ,and a vacuum test.

Many years ago I heard a seasoned racer say "you start at the tyre footprint and work your way forward, then up through the engine, and eventually you end up at the accelerator pedal"

This is so true in many cases

 

I am wondering if the heads can be milled, probably could handle .050 but I don't know where that would put the cc's. Edelbrock for answer.

 

I think he corrected himself on the CC size. They are 60cc as I recall, but not 72?

 

The Flat Tappet Cam with roller lifters !!!!!
I’ll bet a doughnut, a cup a coffee and a dollar this is the problem.
1) Profiles are not the same
2) something or many something’s are going to wear at a rapid rate.
Put the factory stock cam back in !!
See if it runs good
Hopefully still have original cam, fairly inexpensive and easy to swap.
Sorry didn’t mean to yell but FT cam with rollers sent bells, whistles and light bulbs off in my pea brain.
Good luck
Dan

 

He said he put longer pushrods in with the flat tappet cam. [this cannot be done with roller lifters]

My interpretation, is he pulled the roller cam and lifters and replaced it with a flat tappet cam and lifters he already owned. [so we can assume he also used the matching lifters that were already broken in]

If the lifters were mixed up, it could've chewed a lobe BUT this would've shown up as a noisy tappet and rough running long before it became a performance problem.

I agree with the stock roller cam suggestion but he could do the rear gears first before opening up the engine.

@Brandon141 have you tried thrashing it up the road manually holding the gears in 1st to get some revs out of it.
Your engine should pick-up some grunt at about 3-3500rpm

 

I don't care what cam or engine mods mods
2.5?? gears with a over drive trans is a problem even if he fixes the engine issue.
It's a heavy car with a small engine and a stock stall.

I'd run 3.70 ish gears with the OD .
I have 4.11 in my Mustang and OD and it's a bit to low geared for the interstate, long trips. I wish I'd gone with 3.73 gears for this street car.
If I was racing it or not doing interstate then my 4.11 are OK.
The other issue is with the Ford OD auto it gives shift right at the wrong time going into OD when it's pulling way to hard. Rough on the trans snd in stock form I can't prevent the shift .

That cam is way to big and unless you checked it with a degree wheel who knows were its really at . It's likely retarded from the sounds of it. That boat needs a torque making engine not a high RPM engine with those gears and weight . In top gear you would need to be going 220 MPH to have the RPM at peak HP.

IS That a 600 holley ?

The whole point of a OD is to allow lower rear gears so you can accelerate faster . I have 2.56 gears in a vette woth a turbo 400 and at 55 the stock converter is not even locking up yet . With a OD I'd be idling LOL.

OP your going to want to do gears no matter what so I'd pay the toll first . Then if the engine dosent run right fix it.
I'd do a compression test if it's low I'd bet the cam is to retarded for any use under 3500 RPM

 

It was a brand new cam and matching tappets!

And I haven’t tried rolling in 1st and revving it out. I will definitely try it on Sunday when I get back home.

 

Brandon141 I owe you an apology should’ve known you changed lifters with the cam.
Good luck
Dan

 

No problem Dan. This is a long thread!

 

He has 26.85" diameter tyres , so it would be better with 4.10's

This is a Free Test
2.73:1 gears in 1st gear [2.40:1] is slightly lower than 4.10's in 2nd gear
So it will need some urging to get off the line initially then it should wind out if you hold it in first

[In theory you should get 73 mph in 1st @ 6000 rpm]

AOD's are an amazing trans, But there is one problem [no 2nd gear hold]
You have 1 , 3 , OD , N , R , P , So to hold it in 2nd you need to click into 3 then back into 1 [after it shifts into 2nd]

Do all the free tests before throwing $$$ at it [unless you like blowing $$$$ on experiments for other people]
Also did you degree the cam when you installed it?

 

Funny enough my old Fordomatic worked the same. Had to pull it back into low after it shifted into second , then up shift to drive.

 

Wait, WHAT? Roller lifters with a flat tappet cam? That can't work either, along with that super long legged rear gear. Those bits are not interchangeable, the distributor gears aren't compatible, you've got a miss-mash of parts that aren't designed to work together.

 

Look at post #113.

 

One thing I would do before changing any parts. Hold the engine at about 2000 RPM and pull off one plug wire at a time, just to make sure you don’t have any dead cylinders for whatever reason. Also spray in some carb cleaner and create a vacuum leak at 2000 RPM, just to make sure the fuel mixture is somewhere in the right ballpark.