Your thoughts on engine for road racing

[CarFreakGT]

Hello, all. I know that there are several of you who road race or autocross, and who regularly visit the forums. I would love to give road racing a try in the future, but my 68 coupe is far from being ready for any of that--in both time and its condition. This late winter/early spring I'm hoping to be able to rebuild my front end.

When I do my front end, I am considering pulling the engine and rebuilding it as well. My intent right now is to just do a basic rebuild so that I can get the car out and enjoy it next summer (weekend cruising, etc.). Looking to the future, what considerations should I be thinking about for future growth and projects w/ my engine/tranny. Big torque? Big HP? What kind of power curve would be best? Auto/manual tranny? I prefer a stick, but I have an automatic and a tranny swap is low on the priority list right now (barring HAVING to do one). Keep the 302? Stroke it? Consider 351? It will be quite a while before I do anything major w/ the engine, but I like to look ahead to keep me motivated, and to get me in the right frame of mind.

I'm sorry this is vague. I'm just trying to get an idea about how I'll have to think differently for a quick car on the road vs. a dragstrip. I've been doing a lot of searches and my main concern right now is suspension, brakes, etc. to get a safe and solid foundation under me. I'm not dreaming of annihilating track records or anything, just a solid, quick car that can handle.

Any thoughts from those of you w/ experience are appreciated! Thanks!

Bryan

 

[BullittStangV8]

I would say there are a couple things to consider:
1) Engine weight
2) engine height/placement
3) SUSPENSION
Going with aluminum engine parts will help keep front end weight down, and help front rear weight distribution. Also, the height of the engine effects roll center/COG. Also, as you probably know, it doesnt matter how much power you have if you cant get it to turn. I would rather have a underpowered great handling car in a autox then a high powered car that can't rotate. BUT if you are addressing the engine issue now, then I vote for a 331/347 combo from a stroked 5.0. The parts are plentiful, and it would work with some of your components that you have now.
check out www.corner-carvers.com
They have allot of good info about what it takes to make a good autox/road race car. Also, I suggest doing a search there first, as the guys tend to flip out if the same idea/thread has already been posted.

 

[fvike]

A little bit of everything...

I'm not that experienced, I've just been to a couple of track days, but I got a few ideas anyhow. Not so much on the engine, but on other things...

First off, if you haven't been to the track yet, do it. You'll learn so much about your car, and what needs to be done.
The first time I was at the track, my engine was like it's now. 351W with some 400 hp. The suspension and brakes was bone stock, except a Shelby drop in the front. I had 17" wheels, and very good tires, Michelin Pilot Sports. Good tires are the cheapest insurance you can have for a track car, or any car for that matter.

What I learned from that first track day was that my brakes sucks, my suspension sucked, steering had to much play in it, and overall car feeling wasn't the best. I also learned, that dispite having a good strong engine, the rear end gearing (2.79) is way to low to get any punch comming out of corners.

This summer, I had installed TCP front coil-overs, subframe connectors and power rack & pinion. Now I can do more "point and shoot" driving, I got better feeling with the car, because it is stiffer, and cornering is better because of steering feedback, heavier servo and better camber. The car doesn't lift on the inside like it used, but sits down on the inside tire, like it is supposed to. I can tenter corners at a higher speed than last year.
My brakes still sucks, and because I have an automatic, I use the brakes alot. It's an FMX, so it can be manualy geared, but it is hard to do with the high shifter. It's not precise enough. I still haven't done anything to the rear end, so speed out of corners still require kickdowns to get up to speed.

I drove my brother's '70 340 'cuda at the track this year also. I actually had more fun in that car, despite it having a stock 270-280 hp 340 engine. He had just finished a resto, so the brakes was way better than mine, but they was still stock. He also had stock suspension, except Hemi torsion bars, and poly brushings. The 'cuda actually has good front end geometry, but the big difference was his 727 torqueflite auto. Because of the short slapstick gearshifter, I could easily manualy shift the gears. This made me less dependant on the brakes for entering corners.
In the Mustang, I stand on the brakepedal the last 100 meters before the corner, while in the 'Cuda, I just downshifted it, and maybe touched the brakes just before turn-in.
Advice: go for a manual transmission. Both me and my brother are looking into the Tremec TKO-600.
Here is a video of the 'Cuda on the track. My brother is driving. http://video.google.com/videoplay?docid=3898514208084208164&q=cuda%2Bacr
I also have a video of me driving the Mustang on the same track, I'll upload it if you want to.

How you should build your engine is a bit dependant on your local track, but build torque if it's a tight track with lots of corners. If it is a track with long streches and high speeds, I'd build for HP. Anyhow, rear end gearing is very important to get right. Too low, like mine, won't get you out of the corners. To high won't let you get into top speed on the straights. I'm thinking about 3.70 for my car.
Oh, and get a chambered roadrace oil pan to hinder oil starvation in tight bends. On some of the bends at my track I go off the throttle because of this. I'll get a roadrace pan soon. Oh, and a oil pressuere gauge. It's to damn expencive if the idiot lights comes on.

As for suspension, I went with TCP because of tuneability and availability. Subframe connectors is the most bang-for-the-bick upgrade you'll ever do. Don't forget the rear end, it need to function properly for the front end to be able to do it's job. I can feel that my stock rear end is a bit "nervous" sometimes, so I'll do a coil-over upgrade when money allows it.

Brakes: Yes please! As big as you can fit is the thumb rule for track cars. But on my brother's 'cuda, stock brakes are adequate for a stock car. However, my stock brakes isn't good enough for the speeds my 400 hp engine is capable of. After getting better suspension, I got even higher speeds, and the toll on the brakes was even higher. I'm upgrading them this winter. I got 17" wheels, so I'll go with 13" Wilwoods and a hydraboost. This uses powersteering fluid to power the brakes, and it "stores" pressure, so you still got power brakes if you stall the engine. Also it isn't prone to suffer from low manifold vacuum.

That's it I think. A vague questing needs a broad answer!:Track:

 

[BullittStangV8]

Good point about the transmission! I forgot all about that. Like posed, a big gain that you get with a manual in a autox car is that you can tranny break, and make sure your in the right gear prior to entering the turn. That, and manuals are also lighter, and light weight is your friend in a racecar.

 

[chepsk8]

From my years of Turning the twisties, I have found that a big HP number is not the ultimate goal. I like a nice, wide powerband with gobs of toruque, so when you come off a corner, you don't have to row the gearbox as much, instead be able to just hammer it. Also, it has to be rock-solid dependable, ond not run hot, as many sessions run 20 to over 60 minutes, and you are basically floored or braking. The bottom end must be rock solid to handle the stress. Camshaft & carb will determine where the motor runs.

Good gears, usually from 3.55 to 4:10 is where you will be, and suspension that can both transfer the power to the road, and corner is primary.

In running my Cobra, I have found I am not the fastest car on the straights, but I kill them with Killer brakes and the ability to carry better corner speed. That's why the 289 Cobra was always a better race car then the 427.

 

[allcarfan]

cant go wrong with a GT40 crate motor from Ford

 

[86bluecobra]

I would also say go with a stroked 302. Build it to rev high. I mean look at the old Trans Am cars. Engines that like 8500 rpm. The problem with the 351w imo is its wieght. Yes it makes gobbs more torque then the 302 but to add all that extra wiegh to the front of a car that is going to try to corner is self defeating. Most of your time should be spent on suspension mods. I like the TKO 600 tranny for a set up to go road racing.

 

[Gailahan]

I would also say go with a stroked 302. Build it to rev high. I mean look at the old Trans Am cars. Engines that like 8500 rpm. The problem with the 351w imo is its wieght. Yes it makes gobbs more torque then the 302 but to add all that extra wiegh to the front of a car that is going to try to corner is self defeating. Most of your time should be spent on suspension mods. I like the TKO 600 tranny for a set up to go road racing.

It is a misconception that the 351w weights a ton more than the 302. According to <a href="http://en.wikipedia.org/wiki/Ford_Windsor_engine"> wikipedia </a> the dry weight of a 351w is about 25 lbs more than a 302. Not a whole lot considering the extra strenth and power when compared to a 302.

 

[86bluecobra]

It is a misconception that the 351w weights a ton more than the 302. According to <a href="http://en.wikipedia.org/wiki/Ford_Windsor_engine"> wikipedia </a> the dry weight of a 351w is about 25 lbs more than a 302. Not a whole lot considering the extra strenth and power when compared to a 302.

I don't buy that it is only 25 lbs more. My bro in law and myself carried my 351w block around a bit to get it out of my house and to my car. We are both 6"3" or better 225lbs at the time. (married life has been good to me now i'm 265lbs) that block with crank and pistons was a beast to move around. I really think my short block 351w is as heavy as a 302 long block.

 

[86bluecobra]

found a little info on the net. 351w wiegh 510lbs where as the 5.0L are in the nieghborhood of 450lbs.

 

[69gmachine]

Put aluminum heads, intake (carb) and water pump on the 351 and subtract 75 lbs. The 5.0 already has an aluminum water pump, and the aluminum EFI intake is a lot heavier than a 351W carb intake. Add light weight headers and a late model mini starter, and the race prepped 351 is 15 lbs less than a similarly equipped stock late model 5.0. Of course if you add aluminum heads to the 5.0, the Windsor can't touch it, but the point is the Windsor at its fighting weight is light enough to let your car handle quite well. Every pound you can take off the front matters, but there are plenty of other places to lighten the load. I'm sure a good 331 or 347 would be more than enough to have a fun track car, and my 408 is extreme overkill for my skill level, but boy it sure is fun to nail the throttle!

 

[DukeGnarley]

5.8L/351 - 385HP GT-40 ALUMINUM HEAD FORD RACING PERFORMANCE CRATE ENGINE ASSEMBLY

Weight: 543.00#

5.0L/302 CID SMALL BLOCK 360 HP "Z" HEAD FORD RACING PERFORMANCE CRATE ENGINE ASSEMBLY

Weight: 549.00#

something isn't making sense here.

 

[bnickel]

i wouldn't do anything to the engine at this point unless it is truly in need of a rebuild, other than a good baffled oil pan and a windage tray. those can be done without pulling the engine. if it's time for a rebuild anyway, then you have a ton of options.

i would focus on the suspension and brakes first. you don't need a full tcp setup but if you can afford it it certainly won't hurt. i noticed you already have a set ORP roller perches and that's a good place to start, also consider John's upper and lower arms and a set of heim jointed strut rods. if you have manual steering you should get the roller idler arm. do the shelby drop (or the 1-34" drop) and you'll probably also need a bump steer kit. on the 68 you can't do the quick steer kit like you can with the 65-66 cars so i'd suggest the pro-motorsports bump steer kit as it also quickens the steering. 1" front sway bar should be good as well.

for the rear suspension a good set of 5 leaf springs with poly bushings or global west del-alum bushing kit will do you good. rear sway bar is up to you some people like them some people don't, it all depends on your driving style really. a watt's link or panhard rod is a good idea too, personally i'd go watts link, either fays 2 or evolution motorsports would be good.

now the brakes, front, i'd go with a 12" rotor and 4 piston lincoln/t-bird caliper personally, but you can probably also get by with an 11" rotor and 4 piston 67 mustang calipers. the stock single piston calipers just won't cut it IMO, some people make do with them but if you stay with the auto you'll be using the brakes more. i wouldn't risk using them personally. there are other options too, Baer, wilwood, etc. or you could just adapt a 2 piston PBR caliper to your current brakes and still be miles ahead of the stock single pistons.

rear brakes-you'll proobably be fine with your stock rear drums for now but consider upgrading to a larger rear drum or rear disc at some point, most of the vintage racers are quicker with the bigger rear drums because they don't drag like rear discs can.

don't forget the sub frame connectors!!!!

i'd also suggest rear gears as well, 3.55 or 3.70 would be a good start depending on your local track.

get the best tires you can afford. BFG radial ta's don't generally make good track tires. you need something sticky!!!


that should get you plenty of car you can use now and will allow more engine later down the road as you upgrade the engine.

 

[1966conv]

"on the 68 you can't do the quick steer kit like you can with the 65-66 cars so i'd suggest the pro-motorsports bump steer kit as it also quickens the steering."

Not true! It takes a little imagination but is a real simple swap. Start with a 65/66 PS gear box and send it to stanger53 (IIRC) and have him convert it to a 1" short sector shaft. On my 68, I went with this gearbox, 66 manual drag ling with 66 inner tierods, 70 Baer bumpsteer outer Tierods (due to using 70 spindles) and the Cobra Automitive Quicksteer setup with roller idler arm. I also added ORP Modified UCA and LCA along with his roller spring perches and the www.streetortrack.com adjustable struts.

The biggest thing I've found is that I need more seat time. This car I'm building right now is the result of a couple years of time in a similarly modded 66. HP is a wonderfull thing, but you have to stop and steer first. Learn on street tires first, track tires give a sense of too much control at the beginning. learn from your shortcomings and build from there.

If you're just out there for fun, if the car itself is prepared right, you won't see that much difference between 275 & 400 HP at the beginning and too much could be dangerous.

 

[BullittStangV8]

If you are needing a rebuild, then by all means I would suggest doing it. However, if you simply WANT to change engines, I would hold off on it. Why not get the suspension dailed in, get driving skills dialed in, and "learn" on the old motor. IMO push the motor hard now (unless it NEEDS a rebuild), and run it for its worth. In the mean time, you could be working on getting parts together for a bigger engine build. If your going with a 351/302 that is going to be making allot of power, theres not going to be too many engine components off of your 289 that will handle it.

 

[CarFreakGT]

Thank you SO MUCH for the input everyone. I'm trying to soak it all in. I do plan to contact John at Opentracker in the future--not too distant future, I hope. When I bought the spring perches, I was really impressed w/ how accessible he was and he seems to genuinely want to help you get what you want out of your car. My primary concern right now is the suspension, and as funds grow a little, I will be contacting him again. I currently have power discs on the front, done by one of the p.o.'s. The 302 that's in it now is pretty tame w/ a 2-barrel in need of a rebuild. I'm going to rebuild that (the carb) and see how the engine runs in general. I want to get it road-worthy by Spring so that I can drive it more regularly and better prioritize what I want to do to it mechanically.

I'm sure I'll have more questions as I read through the posts again! Thank you again for all the input so far, and please feel free to add more!

Bryan

 

[65ShelbyClone]

It is a misconception that the 351w weights a ton more than the 302. According to wikipedia the dry weight of a 351w is about 25 lbs more than a 302. Not a whole lot considering the extra strenth and power when compared to a 302.

Do not, I repeat, DO NOT believe everything you see in Wikipedia. I could go on there right now and edit the weight difference to whatever I please. I have found many erroneous facts of all kinds in there because it is written and edited by the public. It is not a reliable or even credible source of information.

i wouldn't do anything to the engine at this point unless it is truly in need of a rebuild, other than a good baffled oil pan and a windage tray. those can be done without pulling the engine. if it's time for a rebuild anyway, then you have a ton of options.

i would focus on the suspension and brakes first.

I thought about all the engine recommendations I could make and then realized that you are more on-target.

The most gain will be realized by tightening the nut behind the wheel, not making more power. The only time upgrades are necessary is when the driver becomes good enough to the point that they are actually limited by the car, not their skill level. Even then, the engine is usually the last limiting factor since oad courses are more about keeping speed through turns than accelerating.

The 302 that's in it now is pretty tame w/ a 2-barrel in need of a rebuild. I'm going to rebuild that (the carb) and see how the engine runs in general.

Depending on the compression and/or leakdown results, you might get by with just warming over the 302. Headers and a 4bbl carb/intake would make a good improvement. I guess it could be a good opentrack practice engine.

 

[bnickel]

Depending on the compression and/or leakdown results, you might get by with just warming over the 302. Headers and a 4bbl carb/intake would make a good improvement. I guess it could be a good opentrack practice engine.

definitely need to upgrade to a 4v carb/intake if you only have a 2v now. headers and dual exhaust would also be a good idea, but if you need to add duals to replace a single exhaust then go ahead and do a 2.5" system to support any future engine mods, it will kill some of the power of a stock 302 especially down low since it's really too big for that engine but there's no sense in spending the money for an exhaust system twice.

 

[65ShelbyClone]

Yeah, and the 2.5s will be one less thing to get when the engine is built up.

 

[enyawix]

if road racing = red light to red light you want BIG torque.
You will beat cars making MUCH more power.