I'm in the planning stage of my rebuild . I have a 302 that has been bored over .40 that is blowing smoke badly. I want to put a new motor whether it be a 302 or 351 that has aluminum heads. So I ask is the procomp brand good and should I try to rebuild my 302 or scrap it for another motor?

 

Dear skates21,

There is simply too much unknown. I've put together a list of questions that will go a long way towards answering the questions that seem most apparent. The questions do not reflect my opinion of you or your project.


To get an idea regarding the condition of your 302:

1. How old is your 302?
2. What was the condition of the 302 when it was overbored?
3. How many miles were on it when it was overbored?
4. When was your 302 last overbored?
5. How many miles have been put on it since it was last bored?
6. Has your engine been apart since it was first assembled after the last time it was overbored?

To get an idea whether the Procomp heads are suitable for your application, we need to know the intended usage -- from what fuel you're going to be using, to how many miles each week the vehicle in which it is installed will be driven on the street, to how many miles each week the vehicle in which it is installed will be driven in competition.

The reviews of Procomp heads that I've read tend to strongly indicate the heads are designed to compliment relatively large displacements, high-lift valvetrain and high rpm -- which can be fine if you're building a drag-racing vehicle that you trailer to and from the strip, but that's not what you want in a vehicle that you drive 100-or-more miles per week.

Also, the reviews of Procomp heads that I've read tend to strongly indicate the heads are "not quite ready for prime time" when you get them (unless, of course, you've had someone -- that knows what he or she is doing -- prepare the heads before you assemble the engine).

They're not exactly raw castings, but if you're not accustomed to doing a *lot* of detail work, they're probably not what you're looking for: you can easily spend the difference in price (between the Procomp heads and a premium alternative) getting the Procomps into a usable condition, especially if you don't know what you're doing.

Finally, I add this anecdote:

I was reared to respect property, to take better care of other people's stuff than I took of my own -- and to take care as well of my stuff as I was able. That didn't mean never mashing on the go-pedal, but it did mean that I was always acutely aware of the costs involved in so doing.

I attended high school with a rancher's son; he drove a very (exceedingly) nice 390-powered pickup. One day, he asked me how he could blow-up his engine: he wanted a new truck, and his dad wouldn't buy him one until he "blew up" the one he already had.

I simply couldn't wrap my head around what he was telling me: he wanted to know how he could destroy a perfectly good engine -- not to hop it up, but to simply destroy it in a way that wouldn't reflect negligence. He insisted he couldn't sell it; I don't recall why.

I tried to explain to him the value of a dollar; he answered that if he "never hit a lick at a snake for the rest of (his) life, (he) had already more money than he could ever possibly spend." However accurate was his such declaration, ethics kept me from helping him in that regard.

He later told me that he had the engine bored 0.030, and the stock pistons and rings re-installed; the engine was noisy and it smoked, but for weeks it survived the worst he could throw at it. Eventually, the engine relented in a pasture in which he had "gone mud-riding."

According to what he told me, the engine only stopped after he put the transmission in neutral and held the accelerator against the floor for more than half an hour. Was his account true? I don't know: I wasn't there, but he had no reason to lie to me. And he got his new truck.

If your 302 has been bored 0.040 already, it isn't overheating and it simply smokes from blow-by (not from oil getting past the valve guides, not from oil being sucked-up from an automatic transmission), and if you also have 0.040-over pistons and rings in your cylinders, then

You probably want to have the block sonic-checked for wall thickness before boring it any further; however, there is the possibility that it can be honed and re-ringed, which would save you not only the costs of boring but also the costs of new pistons.

On the other hand, a 302 from a salvage yard is probably not going to be all that expensive; find one that's still in a vehicle that got rear-ended or T-boned behind the front fender (preferably, behind the passenger compartment) -- where the engine compartment is relatively pristine -- and get that engine. There are other tips, but they're off-topic.

Just FYI: the 351W engine mounts are different from those used on the 302; however those used on the 429 and 460 are the same as those used on the 302. It's getting harder to find a 429/460 in a salvage yard, but here's the good news if you find one:

(a) You can turn a 429 into a 460 simply by swapping in the 460's crank and pistons; and
(b) A very mild 460 can be tuned to make well over 500 horsepower on pump gasoline; and
(c) Using aluminum heads and an aluminum intake on the 460 can get the engine weight into the same neighborhood as the factory 351W with iron heads.

 

No.. they're exactly the same.. maybe it's a 351m you're thinking of.

As for Procomp heads, they're OK but not exceptional, if it's price you're shopping on then RHS irons perform better for about the same money. I agree about the points made above though, we need to know more about your truck and how you use it to make sensible suggestions. A built up 302 could be good but if you're into big tires and mud then a 351 would ba far better, so like we said.. it depends. There are lots of other engine build threads on this site so maybe take some time to search a few of the sections just to see what is possible and what it'll cost.

 

To get an idea regarding the condition of your 302:

1. How old is your 302? 25 years give or take a couple of years.
2. What was the condition of the 302 when it was overbored? My father-in-law bought a re-maned long block. The block was bored over .40 basically new.
3. When was your 302 last overbored? It has not been since he put the motor in the truck.
4. How many miles have been put on it since it was last bored? Unsure of the exact mileage but probably around 50 to 60 k
5. Has your engine been apart since it was first assembled after the last time it was overbored? No the only work done was the aftermarket headers were removed and manifolds were re-installed.

I thank you for your time. I really want to rebuild this block . I talked with a friend last night and he said basically the same as you that it may just need to be honed. Will see I guess. As far as the heads go I'm not real sure what the difference between the aluminum vs cast iron are except wieght and heat transfer. I had seen that the pro comps were cheaper in price but have heard that they were not a good brand. I'm not building a truck for the track but for everyday use but want some pep when I get in it.

I'm definitely gonna stick with the 302. I thought that the mounts were the same on the 351 but since they are not I want something that will drop in with no modifications.
Thanks , Skates21

 

The truck is two wheel drive. I might pull a car on a trailer one day but that's about all the load that will be put on it.

 

Err, yeaaah
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Twenty-five years ago was 1986 -- not a bad year for the 5.0 in Mustangs, but I can't recall specifics about the 5.0 in trucks from that year;

Complicating things is that the 5.0 was "still in development" across that general period (the few years immediately before and after) as year-to-year changes that don't really affect assembly could noticeably change performance when sticking with original parts.

As I recall, heads used in trucks were generally more desirable among racers than some of the heads used in passenger cars; however, I don't get the impression that you're intending to race this pickup (at least, not on a "pro," "semi-pro" or "pro-am" level). You might even benefit from (downgrading) to "bad" (from a max-power perspective) factory heads, but that's not sexy.

Here is probably what I would do:

(1) Establish an overhaul fund that included the costs for all the goodies I wanted, plus the cost of 2 or 3 salvage-yard engines (just in case my core was bad and I needed to get something else from a salvage yard).

Doing this beforehand will save you more grief than you can imagine. Trust me: I discovered this lesson the hard way.

Also, gathering your funds beforehand will (a) help you to understand exactly where your money is going, (b) give you the opportunity to search for bargains -- meaning you get more for the money you spend, or you achieve your objective while spending less of your money, (c) minimize downtime -- a dead vehicle in the (garage/back yard/driveway, etc.) is a serious demoralizer and a constant source of grief (even if you live on a farm or ranch).

(2) Pull my engine and disassemble it, noting what castings I had and checking to see if the parts I wanted to keep were reusable (or if I'd be better-off replacing them, etc.) -- and I'd check to see what needed machining and what was too far gone to fix with machining.

In the old days, people would sleeve a block; some still can, but it's way expensive when you consider the cost of a good block from a salvage yard.

Recommendations:

My impression of your performance objectives suggests that a mild 302 would satisfy your performance goals quite nicely; if I were in your proverbial shoes, I'd look for a "hydraulic flat tappet" or "hydraulic roller tappet" cam setup probably:

(a) From Ultradyne (who will grind a cam pretty much any way you want it, for a price -- and who likely has something "off the shelf" that will fit nicely in your budget, but they specialize in tailoring each cam to the customer, so that the customer gets the product he or she most wants). No, I'm not an Ultradyne fanboy and I don't get anything whether you buy from them or not, but I've heard nothing but the best out of their sales and support departments. Just FYI.

If I was the customer in this case, I'd complete their Ultradyne/Bullet camshaft recommendation page (available online at ultradyne.com) and submit it before calling them to talk about it. Odds are good that their initial recommendation will be close enough that I won't need tweaks, but I'd probably call to verify the recommendation fit my expectations for idle quality and basic rpm.

Actually, that's true about what I'd do regardless the camshaft brand I elected to use: get an initial recommendation, then call to discuss it with the grinder. Maybe they want to change the lobe separation or something else, to give me a product better-suited to my application than the baseline "off-the-shelf" product; if I don't talk to someone, I won't be sure until I try the cam -- and that's a lot of work, to be "kinda satisfied."

A few hours of inconvenience now will go a long way towards preventing hours or even years of future dissatisfaction.

(b) From Lunati, 306A1LUN is probably a good start; their earlier "High Efficiency" cams (06603, 06605, 06606) probably aren't bad, either; however, my ideas about what you want could be way off, so you should do your own homework.

(c) From CompCams, I would consider [flat: XE250H, 252BH or 252H; roller: 260HR].

I'd be looking for something that gave me the best combination of idle, fuel economy and low-rpm power -- something with a "basic rpm range" between say 600-800 rpm on the low end and not more than 4800-5000 on the high end.

I'd probably stick with the factory intake if using fuel injection, but if I was running a carburetor, I'd consider a dual-plane like the Weiand #8124 Street Warrior with the recommended 570-cfm carb. I know that sounds awfully small, but some of the sigs in the thread at Edelbrock vs Weiand Intake - MustangForums.com show impressive results from the tiny pot.

I'd get the block prepped for my pistons of choice -- which would mean coordinating recommendations between my cylinder head supplier and my piston supplier. Hypereutectic pistons are fine for the described use.

If I was feeling particularly fancy, I'd opt for a replacement reciprocating assembly, but instead of going for more displacement, I'd probably just go for something giving me longer rods (400 SBC) and a shorter piston. The longer rods would free up a little torque and lower the side-load imparted by the pistons on the bores (making the block and the rings last longer).

And, I'd shoot for a static compression ration (with aluminum heads and a "high-efficiency or fast-burn" combustion chamber) around 10:1 -- maybe a little higher, if I was using fuel injection or DRLAs. Properly tuned, that should let me run 87PON gasoline -- which is fine in a pickup.

Best wishes, but remember: as with all things automotive, YMMV.

 

Got another question for you say I go with the weiland intake how effective would a car spacer be as far as power is concerned?

 

Mainly, it's going to depend on your cam and on your dynamic compression and on the specific carburetor -- and the design of the carburetor-spacer itself, of course. Sometimes, a spacer helps; sometimes, it hurts; sometimes, it has no noticeable effect.

Generally, you want to keep plenum (and runner) volume as small as you can without hurting horsepower; however, without having your particular combination on a dyno, any predictive "answer" is going to be pretty much guesswork.

Are you thinking about using a spacer for nitrous, or are you referring to a factory-installed adapter (usually has "lots" of vacuum lines and maybe an EGR fitting), or are you thinking about a plain spacer?

On Tuning

Regardless the path you chose, the importance of tuning (re-tuning) each time you change anything -- from the muffler to the carburetor, from the radiator to the air filter -- cannot be overstated.

Some will tout a "general" tune -- meaning that the engine will function over its intended operating range -- commonly, either (a) without regard to how well or how efficiently it performs, or (b) with the goal being the least-inefficient performance regardless the conditions under which it is operated.

This is certainly a noble goal, but it is definitively unrealistic: each state of tune optimizes (the engine, in this case) for a particular set of circumstances -- an exact temperature and composition of the ambient air, an exact temperature and rate of heat extraction and dissipation of the coolants (the liquids flowing through the engine, and the air flowing around the engine), a particular rpm and load.

Dynamic tuning represents a series of compromises pre-programmed by the tuner and, to some extent or other, by the operator -- all in an effort to achieve some particular performance objective. Examples of such programming range from bobweights and springs on a mechanical-advance distributor, to computerized maps and algorithms designed to determine ... for instance ... spark or injector timing. I've even seen people "tune" with vacuum leaks.

Sadly, tuning -- especially tuning of carbureted engines -- has become a sort of mysterious black art; the reason is simple: the people that manipulate public opinion stopped promoting tuning as a value among the automotive community. This has led to a situation in which once relatively common information has been lost to a handful of "wizards" steeped in the occult and trained in the mysterious ways of the obscure.

If you're one of those "wizards," and you are reasonably good at marketing yourself, you can pretty much name the price for your technical prowess. If you're not, hope that you can find such a person that has scruples.

Tuning problems occasionally affect even relatively-new, low-mileage factory-original vehicles -- admittedly, this is less of a problem in the age of computerized drivetrain management than it was in the years before EFI became standard equipment on new vehicles.

Don't be put off by tuning, or discouraged from it by those who would try to shame you from it: tuning is the art of the engineer, the person truly enlightened regarding how the whole thing is supposed to fit together and the principles whereby it operates; he or she has a perspective that transcends the automobile.

Warning Concerning Use of Nitrous Oxide

The camshafts I suggested earlier are ground with very tight (for the street) lobe separation and are incompatible with the use of nitrous oxide. If you think you might use nitrous oxide on this engine, you will need a camshaft having "much" wider lobe separation angle (ranging typically from 112-116 degrees, instead of from 108-111 degrees) than the indicated camshafts.

The cam grinder will take into account your setup and together you can decide on what is the best cam for you (114 degrees is usually a good starting point, but the cam grinder will usually have a better understanding of its lobe profiles and how they interact.

It will help if you have the exact information from your particular heads (the closer to "as installed" you can get, the better), but in most cases, truly representative data is sufficient.

 

Just a plain spacer. I'm not running nitrous to scary . Ha. I just that it keeps your car a makes the air / fuel mixture more dense. I'm wanting to get 300 to 400 hp out of my motor not that I need it per say but it will be there when I want to get in it...... on a side note I saw on your profile you were from ms. I live in Madison.

 

Sorry I fat fingered that post. I heard that the spacer kept the car cool and made the air/gas mixture more dense.

 

I had a great response typed in, but had to reboot and I lost it and the link I was going to use. A quick search though yields this:

An important note for using AFR heads.

If you're into experimenting:

Keith Black (KB, Silv-O-Lite) makes a piston (KB276) for the 400 SBC rod in a 302 SBF in the following bore sizes: 4.000, 4.020, 4.030, 4.040, 4.060; these pistons add 6.5 cc to the combustion environment as contrasted against a purely flat piston that has no valve reliefs. Flatlander Racing advertises them at $345/set and notes, among other things, "(0.072-inch) spiral wound pin retainers for use with floating pins (included)." <> Here is a photo of the piston. <> Here are somewhat detailed specs about the piston.

Since most people running the 400 SBC competitively have switched to short pistons and at least a 5.7-inch rod, you should be able to pick up a good used set for a little of nothing; on the other hand, since they're not popular, they might be kinda hard to find. If you're really eager, there's a set on e-Bay. All the standard disclaimers apply: I don't know those people, I'm not recommending them, I can't guarantee whether they will or won't rip you off if you choose to do business with them: shop at your own risk. If it turns out to be true, I seriously doubt you'll beat that price.

UPDATE: I accessed the above eBay store from the pawinc.com website, which doesn't guarantee it is Performance Automotive Wholesale, but I think it probably is; their items are on clearance as they're transitioning to sell only early Chrysler Hemi (years = 1951-1958, displacement = 354 & 392). AFAIK, they were a reputable seller.

I can't recall if the Ford crankpins (connecting-rod journals) can be widened to the stock SBC dimensions (although I'm pretty certain you could get an aftermarket crank that had SBC journals); however, there's no real need for that: narrowing the big end of SBC connecting rods to fit the SBF journal width has been done probably since the early-to-mid 1960s. Any *competent* machine shop can do that work; unfortunately, I've been out of that scene too long to recommend anyone local.

Here's how Car Craft Magazine got 400+ HP out of a 306 in 1999 The 280 Megacam has .517 intake and exhaust lift, which is a lot on the street -- and 232 degrees duration at .050, with 108-degree lobe centers; it's a huge cam for a 302, and while you could deal with it if you only make very short trips and mainly romp around on the weekend, the lopey idle and 2500-6800 rpm powerband would simply be nutso in a pickup.

Here's an article about how Car Craft Magazine got 400+ HP out of a 302 in 2009. Dude! They went over 400 "all-motor" horsepower, using a freakin' stock camshaft, and stock guts in the short block! Holy frijoles: 405 hp at 6,200 rpm and 380 lb-ft of torque at 4,300 -- with basically just a top-end swap! Take THAT, Chevy guys and Mopar mavens!

That tells me the AFR165 heads are pretty much what the doctor ordered. From this eBay search, I noted that Jegs seems very slightly higher than Summit on price, if you're pinching pennies. Both Jegs and Summit sell on eBay; I didn't check Craigs List or Amazon or any of the other online sites. The least expensive AFR 165 heads that I saw on eBay for the 302 were ~$1440 (ported #1420s, delivered, from Keith Craft; from the ad, it's unclear if he is indicating AFRs CNC porting or his own, but he gives contact info). That doesn't necessarily mean you want those, but the 1472s from Summit are ~$1450 delivered, without having been modified.

For a "single 4V carburetor" intake manifold, I'd still consider the Weiand 8124 (~$161 delivered) as well as the Weiand 8020 (~$181 delivered). Neither of those prices is for either the Polished or the Everbright finish: it's for the "satin" casting. Curiously, Weiand seems to have gone back to the "Action+" nomenclature for the 8124 (some refer to it as the "Street Warrior," which I suppose isn't PC in an era of lethal road rage). Similarly, I don't understand why AFR branded its heads as "Street Outlaw," since they're 50-state emissions-legal.

There's a head shootout that shows what can be done with the E7TE head on the street; remember this is gross horsepower, whereas the factory engine was rated for SAE net (all accessories installed & operating) -- but at least it isn't EMC-net (where an electric water pump is used). Regardless, that's a healthy engine. Here's the short version of how different heads performed against each other in the test.

As far as I can tell, the cam in the cylinder-head shootout was most likely the Comp Cams #35-349-8 (click link for specs). The same lobe grind (XE264HR) has a different camshaft part number (35-320-8, different specs) when intended to be used with 1.7:1 rockers. I don't think I'd use that exact cam in a pickup; regardless, the three sources identified above indicate it should be relatively easy to build a pickup-duty 302 that makes significantly more than 300 horsepower.