I'm rebuilding the original engine out of my '91 for auto mechanics class (senior year HS). The PO swapped a junkyard engine in, and it's tired.

I took the block and head to the machine shop 2 days ago.
Cylinders all measure ok, and crank is ok. However most of the main and all rod bearings were down to the copper and smelled burnt.
I'm having new cam bearings put in at machine shop, head and block and getting boiled (cleaned) and magnafluxed (check for cracks).

I'm replacing rings, bearings, gaskets, oil pump, and head bolts.
Still considering cam and lifters- they are worn (some cam lobes are down .020", and lifter bottoms are concave instead of convex) I can reuse them if I have to, but would like this cam and maybe roller lifters
Crane Cams 503901 - Crane PowerMax Camshafts - Required Parts - SummitRacing.com
I'm told 302 lifters fit a 300.
I also want new exhaust though
Catco Catalytic Converters 9651 - Catco Catalytic Converters Direct Fit Catalytic Converters - Overview - SummitRacing.com

Without cam and lifters, I'll be have around $400 into it.
I'm hoping to make enough scrapping in the next week or 2 to cover most of the build.

Oh, I also need (sometime, can run now w/o them)
PIP module
TPS
Injectors (might go w/ 302 inj if I do the cam)

Slave cylinder has acted up a few times, should really be replaced while engine is out.

The engine needs to be in the truck and running around the end of april. Of course, some stuff like the Injectors / tps/ pip could be done at a later date, when I save up the cash.

Sorry I don't have any pics now, just though I let y'all know what's going on.

 

It sounds like a nice build. However, keep in mind that a set of used lifters is mated for life to the cam they ran with, and each lifter is a match to each particuliar cam lobe. So, if you mix up the order they came out of the engine, they are trash. Also, you can not use those lifters on any other cam. New cam ALWAYS=new lifters.

Also, I think you said it was a '91. That means it's EFI. With an EFI engine, you have to be real careful with your cam selection, and the one you are looking at is too large for your engine. Check the Isky website. I believe the 256 supercam is computer compatible. If you are looking to keep the cost down, go with a oe cam and lifters.

 

The problem with roller lifters in a 300 is the locking bars (dog bones in a stock with rollers 302). A flat tappet lifter turns in the bore so it will wear evenly, but that doesn't work if you are turning a roller sideways. A roll requires the opposite, it can't turn in the bore because rollers don't roll sideways so you have to find a way to stop them from turning in the lifter bore. I sure if you called up a cam maker they could set you up with a roller cam (have to have a special cam for roller lifters with flat lobes, flat tappet cam lobes are slightly tapered to make the lifter spin) some custom lifters, and don't forget your custom pushrods and a hardened distributor gear. It is doable but it will cost way more money than it is worth. And yeah when talking flat tappet lifters FE is pretty much the odball of the bunch other than them in the V8s 302-460 uses the same lifter as the big sixes.
-John

 

No benefit to using a roller cam in a stock to moderately built engine. The ROI is between none and none whatsoever. Save your money.

 

the high flow cats are a good idea. With an almost stock build I would stay closer to a stock cam. I put the money into the head and went with a stock cam. I had my head flowed. port and polish does not do a whole lot of good with out a good airflow and all cylinders need an equal amount of air.

 

Good point, I forgot about the locking bars for the roller lifters.

I read a post somewhere (can't find it at the moment) about a guy who used the 503901 cam in an EFI 300 and could go 5 mph faster up hills towing a trailer, and got almost 2 more MPG.

Also, according to the manual the bottoms of the lifters are supposed to be slightly convex, I checked mine against the side of another lifter (as the manual suggested) and they are concave.
So it would be nice to replace lifters and cam, but I don't want to spend $120 for a stock cam. I want to give the ol 300 a bit more pep

 

I've also heard mixed results about 250 rocker arms. Some say it clears the EFI valve cover, others don't. Is it enough gain to be worth it?

 

after my research ive found the comp cams 260H seems the best match for a 300...

looks like a nice builld man...post lots of pics

 

I will start taking pics once I get the block and head back from the machine shop.

I found this, think the EFI would like it?
COMP Cams CL66-237-4 - COMP Cams High Energy Cam and Lifter Kits - Overview - SummitRacing.com

Still researching the 250 rockers, it's unclear if they work under the EFI valve cover. Anybody?

I'm going to get all the internal engine stuff done now, then go back and replace some electronics (injectors, TPS, PIP, IAC) later when I have the extra cash.

 

Take your cover, and pull one from the boneyard, and splice them together, giving yourself an extra 9/16". Or, try glueing three gaskets together with longer bolts. Some guys have done that w/o probs.

 

What about an aftermarket chrome valve cover? They are for carb'd engines so they don't have the "dip" in the center for the intake. The only issue is the one I found has 2 breather holes and that's it. EFI 4.9s have 2 breathers and an oil fill. I suppose I could rig something up where the hose to the filter box goes to a Y at the rear breather on the valve cover. But then would the front one be far enough forward to use as an oil fill?
Just some thoughts.

I'm going to mexican chrome (spray paint) my side cover, timing cover, and valve cover. It probly won't look the greatest, but a change from gray I guess. Block will be ford blue (and maybe head too)

 

The crane cam you previously mentioned, will work with your efi.

Think about using course gear metal timing gears, they were put on earlier carb trucks around 79 I believe, youll have to search to get the specific part #, specifically search for posts by username optikal illusion.

I wouldnt add larger injectors unless your willing to modify the stock fuel rail and add an adjustable fuel pressure regulator, along with a wide band O2 sensor/reader.

Honestly, Id build the engine as cheap as possible, invest some cash into a megasquirt or other affordable DIY engine management system, tune it, tweak it, get familliar with timing/fuel management, then think about making real changes to the engine, as the fuel/spark management will be your greatest hurdle...as there is minimal support to reprogram the stock ecm.

 

I'm not dead set on a cam, I might pull the one out of the engine in the truck and if it and the lifters are ok, then use them to save cost.

Just curious which cam you guys think would work better?
Even with buying lifters separately, the crane is still about $30 cheaper.

 

I got the block and head back friday. I painted 1 coat of blue on them. Hoping to get another coat on today (it's kinda windy though).

 

As I said in my first post, check the Isky site for cams. I believe the 256 SuperCam is computer compatible.

I don't think you can swap the rockers to higher ratio on an EFI engine.

Have the bottom end balanced if you are going to keep it. Put the sleeve over the end of the v. dampener to prevent oil leaks. For $5.99 it is a super cheap insurance policy. Install a NEW oil pump, with Locktite on the bolts.


Have your rods reconditioned too.