Featured Technical Rebuilt 302 has no get up! Help.

READ

READ, THE CAM CARD, AND THE RELATED INFO IN THE CATALOG !
Does your car resemble these requirements ?

You don't mention the compression ratio, you don't mention the gear ratio, you don't mention the "total" ignition timing, you don't mention the torque converter stall speed, you don't mention the rear tire diameter !!!!

The cam card does not mention the overlap split (lobe center).

Brandon, seems you bought a low level "race" cam and are trying to run in in cruiser trim. Won't work.
You didn't do your homework when picking the parts for your car very well, or at all. Everything is a "combination". That is, all of the drivetrain must be able to work together smoothly.
NOT fight each other like it seems you have chosen.

Mike

 

New or rebuilt engines can be tight and weak until they're broken in. This can take hundreds of miles on a stubborn engine. Are your ring gaps correct? The last professional rebuild I bought was an 8CM merc flathead. That engine could not pull your hat off your head. The cracked and totally worn out 221 cu. in. engine it replaced had all kinds of power. After about 100 miles of driving on city streets and highways it started to loosen up. Now, with a few thousand miles on it, it has all kinds of power. Also, shouldn't your peak power and converter stall speed kind of match up? I also suspect you have too much cam for what you wish to achieve.

 

I would guess more likely 7.8 to 8.0:1
Add to that the longer duration cam is bleeding off too much cylinder pressure.

The engine will be wheezing down low.

@Brandon141 Cams and Compression are "Bed-partners"
If that engine was my "mistake" , I would cheap out and sell the heads and/or swap the heads for some with approx 58cc chambers and don't be obsessed with 2.02 valves. You want some velocity at low RPM
[or keep the heads and throw a 351w shortblock under them]

 

My Chevys like that too. It makes quite a difference.

 

Right on Target ^^^^RmK57 and Kerrynzl
With the late model 8.203" deck block, 3" stroke crank, 5.090" stock length rod and the typical Speed-Pro 4 valve relief flat top along with the common Fel-Pro .041" thick head gasket and those huge 72cc combustion chambers...
given a quick run through the compression ratio calculator comes up 8.06:1 compression.

That 72cc head was a big mistake, now you've got a rowdy racer cam, no stall converter, likely no rear gearing, in the toilet compression ratio along with large valves and bigger ports so now we see it's no wonder at all why it has less power than the stock engine did.

Extremely poor combination of parts that you really can't fix with just one change.....unless you plan to turbo or supercharger it.

 

Where would the OEM stock 58 cc heads take the compression , if the stock heads would get the compression to approximately 9.5 :1 that engine would likely run good, still would need gears and a converter but I’m guessing the sale of the RPM heads could almost cover stock heads, converter and gears.
Dan

 

Approx 9.8:1 to 10:1
But the longer duration cam will lower static cylinder pressure
I personally would recommend a shorter cam and still run 10:1 if the heads were Alloy [they can run 1 point higher on pump gas]
Then gears and converter aren't needed

The heads and cam swap are "bolt-ons" and the engine isn't serving a life sentence in "machine shop jail"

 

That actually may be the cheapest way out.

 

Thanks,I was looking for a solution for the OP that wouldn’t cost big $$$s or require a complete rebuild so to speak. From our limited knowledge of this engine it sure sounds like low compression is the culprit. Low compression and big cam =

 

How bout some “pop up” pistons.

 

Good idea also
Dan

 

Yep, I've had the pleasure of the low compression big cam experience. Revs like a race car but a dog in the lower RPMs.

Still, has anybody suggested and did you check to make sure the throttle is opening all the way?

 

No, that's incorrect. The 89 engine would have had 13726548. Correct on the current cam being 15426378.

 

Hopefully the carb was checked for function but sometimes the simple things hang us up!
Dan

 

There may be shelf pistons available, so that could be worth checking out. But that would also mean rebalancing the assembly.

 

Or just put a more reasonable cam in it. A little extra lift is okay, but conservative on the duration and overlap. You'll still get good flow with your new heads. As far as installing higher compression pistons, remember that the higher your compression, the more expensive the gas. Relatively low compression with good flow and a mild cam can make good power in the RPM range usually seen on the street.

 

About $700+ the cost of a rebalance and gaskets etc
It would be cheaper to find some [F7EE-AA] GT40P heads off a 99-00 Explorer and back cut the valves and do a 3 angle seat job.
58cc-60cc Chambers ,
1.84" Intake Valves
1.48" Exhaust Valves

Stock GT40P's flow 195 CFM which is good for 370hp with the correct combo on a 306" SBF
[in the real world aim for 330 hp which is a good ask for a 30 over 302]

I've seen Explorer GT40P heads go for $350

 

Thanks guys.
So if I keep the current stall and rear end gear, what cam do you recommend to work well with my heads?

The short block is out of a 90 mustang GT with about 4000 miles on it. I went through the carb and it’s working like it should.

 

Or…. Keep the motor how it is and change the converter and rear gear?

 

40 minutes of searching through Edelbrock performer heads for a sbc doesn't bring up any 2.02 heads with 72 CC combustion chambers, How about a part number so someone can research it a bit.
Every Performer SBF windsor style head I found has 55/60 cc combustion chambers. Those 72 CC must be built for a certain combo.

 

Sorry, they are 60cc combus chamber.

 

There are some kB pistons for bout 1/2 that. Rebalanced? Probably isn’t “balanced” anyway.

 

That’s better.
Your cam folks recommended a 2500 stall.
Kinda one of those “do I spend more to make this cam work or swap out the cam” deals.
One of my friends went thru this recently with a thumper cam. Put a milder cam back in.

 

Yes, that’s the direction I’m probably going to go with. Find a cam that will work with my combo.

 

Besides...
I don't know about anybody else, but I get a little tired of the choppity choppity choppity of radical cams anyway. Oh I like it as much as the next guy, but for the street, a nice low smooth idle with crisp throttle response and actually greater low end torque can be nice for a change.

 

A stock cam with 6* advance really wakes up an engine. If stock 1.5 rockers, adding 1.6’ for a little mid and top end without sacrifice what you gain with the cam advance.

 

Reading through this thread is like looking at the results for a Google search for meatloaf with a lot of combinations and how put it together.
The stock block 289 from my 64 Fairlane has a cam that is very similar to yours just a little less lift but over .5”, back in 2000 when I ordered it it was referred to as a good torque cam and judging by its performance I believe it was. On the street I ran a 3.25 gear stock converter and being able to turn the tires wasn’t a problem. I used a mechanical advance distributor and a vacuum advance 600 Holley carb, the advance was 15* initial 35 all in by 2100 rpm. The carb took a few days of tuning to get it right between the secondary opening, power valve and jets, if I remember correctly the secondary opening took a couple of spring changes I ended up with the second lightest spring. I ended up with a 650 - 670 idle.
My inability to leave things alone had me installing 3.80 gears/Detroit locker for awhile which I didn’t like either one, then I tried a 2800 stall converter with the 3.25 gears which did wake it up but in the end I built a new 289.

As an edit: I would go back and degree the cam, slack tolerances could have bitten you, two to four degrees of cam advancement will help especially with low compression.

 

Is this cam still too big?
CL31-218-2
Duration- 268
Lift- 456

 

I didn't see any mention of rear gear ratio, impossible to select a well-matched cam without that info.
Adding higher ratio rockers effectively increases the cam duration, so keep that in mind. With 60cc heads and other items mentioned, a smaller cam will likely work pretty well, but gear ratio and vehicle weight come into play and should be the driving function in your cam selection.

 

Thank you everyone for the input and suggestions.