[updated:LAST EDITED ON 22-Sep-02 AT 08:59 PM (EST)]It seems to me that a lot of people on this site are hell bent on bolting stuff on for performance before they can actually make full use of it. I hear people putting in(or wanting to put in) expensive computer chips, aftermarket heads, upgraded ignition systems and the like when most of the time the factory stuff well suffice. Unless you spend lots of time at the track most of this stuff is overkill for the street. I've seen some pretty potent street machines where the only aftermarket pieces on the car were the camshaft and in some cases a intake manifold. first of all before making any real performance in an engine the bottom end should really be balanced. This makes the stock engine components (mainly the con rods and crank) basically bullet proof in a lower rpm street application. Next the heads should be ported and polished, which is easy to yourself with the use of a die grinder. Actually there are many books availible that give detailed instructions on how to do this.
One aftermarket piece i do recommend is a good camshaft. Nothing too crazy, something with a power range under 5500 rpm. With all this done and you still want more power than by all means bolt stuff on. At least you will have a good foundation to start from and the engine won't blow up as horsepower begins to climb. I have 89 F-150 that I built a carburated 351 for that will blow away most fuel injected trucks with the usual boltons. It even runs stock points ignition from a 73 Montego. Best of all it didn't cost much yet it's fast and reliable. just my 2 cents, feel free to critize.

 

RC

I would agree with 90% of your assertions. You have to start with a good bottom end and folks are bolt on crazy. Since you are inviting dissenting opinions, I'll give you one on the cylinder head issue. Unless you happen to have a flow bench handy, grinding significant material from you cylinder heads is a shot in the dark. Even from a magazine or book. When you are all done. The bolt on gang here will bolt on a set of heads from Jegs that will crush you in any RPM range ringht out of the box. If you start with one of the better factory castings, you can certainly make some improvements if you know what you are doing. You can't begin to compete with a performance head manufacturer and their unlimited resources, armed with a die grinder and a magazine. Just my 2 cents.

'fenders

 

I agree with building your lower end first. Most of my friends think I am nuts because I am willing to spend an arm and a leg on my lower end. ie... main girdle, oil pump, forged pistons, "H" beam conrods, balance the rotoating assembly, blue printing and so on. What most of them don't know is that I will end up having a smoother idle and a quicker response to fuel then they will. I may not be buying the best aftermarket heads and such now but I can gaurantee that I will be able to handle the upgrades later without breaking something because I over did it on the top end. For example Nitros or a wicked set of heads and intake that are port matched.

One thing I will stick up for is gasket matching of heads, intake, and exhaust. Something as simple as this will make a world of differance when it comes to stock. I am not saying dig deep into the runners or grinding down the guides. But just simply matching the ports with one another makes the engine breath easier. As far as doing a full port and polish job, I will rely on aftermarket companies to provide their best. I would rather pay the extra cash for something I know is done right then to wonder if I missed something or made it weaker by going to far.

 

[updated:LAST EDITED ON 22-Sep-02 AT 11:43 PM (EST)]Totally agree with you guys on heads. the point that i was trying to make was one of cost. espcially here in canada where performance parts tend to cost a little more. If I wanted to blow the doors off 90% the vehilces out there and was spending alot of time at the track, than ya i would consider a set of aftermarket heads, but for the odd time(okay it's more than the odd time) that I want to kick some chevy butt on the street I hardly see the point in spending the money. Now as for a flowbench needed for doing minor (I should have mentioned MINOR earlier) head porting I disagree. Factory castings are, for the most part, messy. They have lots of sharp corners. Simply by smoothing out the area above the valve seat (where there are lots of sharp corners), knocking off that big bump in the exhaust port where air injection occurs and port matching will net considerable gains (i know i have done this). Now this is all provided that you started out with decent casting to begin with. If your pulling a set out of the bone yard and you have to put all new valve seats, guides, valves, springs and such than by all means go and by the after market heads because in the end it won't cost much more. Thanks for responding.

 

yeah, but imagine a motor with balanced reciprocating assembly, aftermarket cam, heads, ignition, etc. There's no doubt that aftermarket heads have more potential to flow better, and most flow better out of the box than even heavily ported C coded heads. Aftermarket cams can be ground to match the "personality" of most aftermarket heads. I don't know about points ignition, I've always had at least factory breakerless, but since I've hooked up my complete MSD system (Pro-Billet distributor, 6A box, coil, Motorsport 9mm wires), I've seen significant performance and fuel milage (+2 MPG) improvements. There's more research and development put into quality aftermarket parts, but I'll admit that a lot of them are not cost-effective. I'm very fond of well-known and reputable parts companies, such as Edelbrock, Comp cams, Crane cams, and MSD ignition. I'll be more than happy to point those that are just hype-oriented, and low quality rip-off schemes, because there are plenty out there. It's really easy to mis-match aftermarket parts too, which is what happens with most over-anxious ameteurs. This is why it's so critical to get advice from experienced people when ordering parts, either here on FTE, or a pro at the parts store. Just be wary, the parts store guys are into sales for a living, so a second opinion is a good thing to have. TK

'77 F100, 302 (the aftermarket Prodigy), C4
Cadet Second Lieutenant John F. Daly III
South Carolina Corps of Cadets, The Citadel
The TorqueKing

 

RC

Agree you can do many minor head improvements without fancy tools. That is exactly what I did to my 302 in my truck. I don't expect anything near aftermarket performance and I thought that was your original point. Sorry if I misunderstood you.

'fenders

 

[updated:LAST EDITED ON 23-Sep-02 AT 00:04 AM (EST)]In responce to the torque king

I do agree with you on the sales end of it. There are many performance stores out there that are just out to sell. The speed shops that ask you how much horsepower you want to make are good ones to stay away from. The one that asks you how heavy your car is, what gear ratio your running, what tire size you have, what your main use of the vehilce will be and questions like that are showing genuine interest in what you are doing and are trying to figure out what parts are best for you.

 

BTW, good to hear from you again 'Fenders, things were starting to get boring around here!

'77 F100, 302 (the aftermarket Prodigy), C4
Cadet Second Lieutenant John F. Daly III
South Carolina Corps of Cadets, The Citadel
The TorqueKing

 

true some people may be a little bolt on crazy, but i know that my bottem end is going to take what ever i can afford to throw at it. its just a stock bottom on my stock 460 with 99500 miles on it. yet with the 'bolt ons' that i have done, i have turned an otherwise slow truck intyo one that is fairly quick being as heavy as it is, and helped it get a lot better gas milage in the process. when i bought the truck it got 8 and i just averaged close to 12 on a recent trip. a lot of bolt ons can really improve an engine, but its when peoples eyes get bigger than their stomachs that the problem begins.

1977 F250 460
C6 Hedman Headers
Dual 40 series
edelbrock performer
holley 4160
msd 6a and blaster coil

 

Warning Off Topic

Torque King

Good to be back, getting a little slow on the 50s truck board right now. We are getting older you know and need our naps. Thought I better pop over here and hype up some aftermarket parts for you. It took you nearly 3 hours to respond to "Aftermarket Blasphemy FTE Post" I would have thought you would get an automatic wireless alert on your CELL or something.

'fenders

 

I like what he's saying, and it reinforces my theory that great parts in the hands of a novice will never be as good as any parts in the hands of a pro. I think that Jack Roush could make a VW Jetta faster than a riced-up Mustang anyday. It all depends on how competent the engine builder is. TK

BTW, yeah, my internet browser has a constantly updating feature where anyone posting on this website and using the words "aftermarket", "bolt-on", or "speed parts" will automatically trigger an alarm featuring a very loud siren, as well as a voicemail/pager alert, which won't turn off until I post a response.

'77 F100, 302 (the aftermarket Prodigy), C4
Cadet Second Lieutenant John F. Daly III
South Carolina Corps of Cadets, The Citadel
The TorqueKing

 

Of course, if you want a big boost in power with little modifications, then a supercharger is the way to go. If you want a HUGE gain in power with a lot of modifications, then, a turbo is the way. Nothing beats boost! Not even inches beat boost! Two engines with the same c.i.d. with one being boosted. No contest. I disagree with the comment about the balancing making the engine "bulletproof" at low rpms. It will help with low end response and make the idle smoother but, it is the high rpms where it makes it more reliable. This is where the speed of the rotating parts increases their mass and the benefits of balancing keep the engine together.

 

To put a lot of "boost" still requires a decent bottom end. You wouldn't put a serious supercharger or turbo(anything over 8 psi) on anything with a stock bottom end. it might last for a while but sooner or later something is going to come a part and when it does your going to wish you had upgraded the bottom end. As for low rpm reliability I meant that in a street application you rarely see anything over 6500 rpm, which is a low rpm application considering that some drag cars run close to 10,000 rpm, and that balancing will make the bottom end bullet proof in this operating range.

 

Agreed, Although, forced induction is actually easier on an engine since you no longer have the negative pressure phase during the intake stroke. Of course, once you go beyond a certain point of boost, you are definitely overpowering the bottom end.