It is time for me to have my 1987 F-150 4.9L rebuilt. It has 174,500 miles on it. I found some pieces of bearings in the oil pan last month. After showing the pieces to a few different mechanics they think they are either rod bearings or cam bearings. So far I have decided I want to have my motor rebuilt and not a remanufactured motor. It will cost around $1,200 for a regular rebuild plus $300-400 dollars for another shop to remove the motor and bolt on parts like intake/exhaust manifolds, distributor, alt., smog pump, water pump, power steering pump, a/c etc., then reinstall the motor and parts.

I looked at clifford's site to see about a cam. Since my motor is EFI it looks like there is only one cam I can run. However it does not give any horsepower or torque numbers for the baseline motor or with their cam.

Will a cam make a difference in a stock motor with 3 inch pipe and 40 series Flowmaster (stock exhaust EFI manifolds)? I would like some extra torque in the lower range. This is my daily driver lifted on 35 inch tires and 3.55 gears.

Are there any other cams that work with EFI and will pass smog tests?

 

I did some more searching and found the Crane 503905 and Isky 331256. Both should work with EFI. I will call the companies and confirm.

Can I bump up the compression and still pass smog? I read that stock compression is about 8.75:1. Will 87 octane support 9:1?

 

crane 500511 is one step below the one you listed.

Both will work with speed density, as to affect on emissions, couldn't tell ya.

Comp cams offers a couple, any custom cam company offers one (usually not as expensive as you might think), check out reed cams.

 

Thanks for the part number. I noticed that both of Crane's cams 503905/500511 have split duration. The 503905 has 204 intake, 216 exhaust.
The 500511 has 192/204.

Competition Cams don't have split duration. 66-236-4 has 206/206.
66-237-4 has 212/212.

Isn't split duration better for smog? I tried a tech. hotline but no one was home.

 

Not necassarily. Stock is single pattern. Duration does play a role, more importantly how much but these are all still fairly mild camshafts. Crower also offers a couple cams.

 

I have spent hours today searching for camshafts! Do you know what stock cam specs are for a 1987 EFI motor? I want to see how far these cams are from stock.

So far I like the Isky 331-m, 108 lobe center, intake/exhaust duration @ .050 is 194.0, the intake/exhaust lift @ valve is .415.

The Competion Cams 66-236-4 (a little pricey) has 110 lobe centers, intake/exhaust duration @ .050 is 206, the intake/exhaust lift @ valve is .433.

I still haven't found out if these cams will pass smog.

 

PM sent.......

 

Clifford Performance said their 264 and 270 cams will pass SMOG. Their 264 has 474 lift and 206 duration @ .050. Still researching.

 

I can't find any cams by Crower. Their page does not load for me. Do you know the part numbers or cam specs?

 

P/N 19210 (idle to 3500 rpm)
248HDP 112 LCA 248/254 184/192 .405"/.411"

P/N 19211 (1500 to 4000 rpm)
252HDP 112 LCA 252/258 192/192 .426"/.440"

P/N 19212 (1800 to 4500 rpm)
260HDP 112 LCA 260/268 202/210 .443/.448"

P/N 19213 (2000 to 6000 rpm)
266HDP 112LCA 266/274 210/213 .456"/.461"

tech line 619-422-1191

 

Can I bump up the compression and still pass smog? I read that stock compression is about 8.75:1. Will 87 octane support 9:1?

Good Question....

 

Higher compression = a more efficient engine.

8.75:1 to 9:1 isn't a drastic jump in compression.

 

87 octane should work just fine up to about 9.5 to one.

 

Sounds like my engine, 178,000 and I also need a rebuild cause the rodbearings are shot and make a killer knocking sound on the highway, my dad and a few mechanics said it sounds like a rod bearing, so Im looking into a rebuild too. It's pretty loud, the cars passing me in the fast lane can probobly hear the knocking as they pass me.

But like someone else said in another thread, it could be any moving part in the engine thats creating this knocking sound. Whats kinda wierd is it only knocks on the highway, at 2500 rpms and above. If I do a rebuild I'll also get a newer performence cam.

 

I'd drop the pan and inspect the bearings before making any decision about a new engine. Use plastigauge if there is any doubt. But don't be driving it with the knock! That could prove to be very expensive.