Beginner Road Track Racing: Feedback on Engine Options Wanted

[Torqueflite]

I’d appreciate constructive feedback from those who have experience in/knowledge about road track racing on some engine options for an upcoming build. I’ve amateur drag raced since childhood and am interested in starting road racing with a dedicated track car. It will be street legal and drivable enough for 30 minutes on a highway to the track where I’ll swap out the wheels/tires, so keep that in mind. I understand many of the principles of road racing having grown up around racers and racing pavement motorcycles, but I’ve never actually beaten a vintage car on a road track and don’t know any vintage road racers for input.

I recently purchased a solid but neglected unrestored 1969 Valiant coupe for the build. It’s a factory 318 4-speed car that doesn’t run but still has the engine and transmission. I’ll weld in frame connectors, a 6-point roll bar, swap in something stronger than the 7.25” axle, etc., and it will get front and rear disc brakes and sway bars. For this thread, I’d like to focus on the engine though.

The track I intend on running has only one straightaway and a lot of turns, so top speed isn’t much of a concern compared to low and mid-range. For now, I’d be happy with 400 – 450 HP at the flywheel, although I imagine even 350 HP would still be fun as a beginner. While the short stroke and big bore of building a B-block 400 is attractive, I want to shave off as much weight as possible so want to stay with an LA build. This is also a budget build to get me into racing before determining future upgrades as I gain experience, so I’m not looking to go all-out or even close to it. A main area of uncertainly for me with road racing in mind is where the balance lies between cubic inches and RPM in that substantially more cubic inches out of an LA will take a longer stroke versus less cubic inches and a shorter stroke. I don’t know what the feel and function of the car will be with a 3.31” stroke compared to a 3.58” compared to a 4” and therefore don’t know if a 318, 340, 360, or 408 is an ideal setup for a beginner to have some fun with enough room to grow into an intermediate level of skill.

I already have a set of aluminum heads and an ED4B intake that will go on the engine, and I’ll note what I have and what I would need to buy and have machined. I'll perform oiling modifications and the like.

Option A – Least Expensive:
360 LA-Magnum Roller Engine. With the options below, I’d be comfortable maintaining 6K RPM with the thinking sustained 6,500 RPM might overstress the factory cast crank. Here are the details:

-I have a low-miles 1994 Magnum 360 engine with the rocker shaft oil galleries to use LA heads. It has clean bores with the factory hone still visible and will clean up with just a professional hone job.
-Use the factory 3.58” cast crank, no machining necessary.
-New I-beam rods with 7/16” bolts (need to buy, unless someone has experience that the factory rods/bolts will handle things)
-New flat-top LA hypereutectic pressed pin pistons to get closer to the deck (need to buy)
-Have rotating assembly balanced
-Have the block machined to zero deck
-Reuse the factory Magnum hydraulic roller lifters (I prefer solids but already have the roller lifters).
-New roller camshaft (need to buy).

Option B – More Expensive:
LA324 (overbored 318). With the options below, I’d be comfortable maintaining 7,500 RPM.

-Have the factory 1969 318 block overbored 0.040”
-Use the factory 3.31” forged crank (need to have it turned)
-New I-beam rods with 7/16” bolts (need to buy)
-New hypereutectic pressed pin pistons (need to buy)
-Have rotating assembly balanced
-Have the block machined to zero deck
-New solid flat-tappet camshaft and lifters (need to buy)

Option C – Most Expensive:
LA340 (using a polyspherical A318 block). With the options below, I’d be comfortable maintaining 8,000 RPM

-Overbore a 1966 A318 block I already have 0.090” to use 340 pistons (the walls are thick and will take it with adequate wall thickness left)
-Use the A318 or LA318 factory 3.31” forged crank (need to have it turned)
-New I-beam rods with 7/16” bolts (need to buy)
-New forged full floating pistons (need to buy)
-Have rotating assembly balanced
-Have the block machined to zero deck
-New solid flat-tappet camshaft and lifters (need to buy)

These are the three entry-level options I thought of using the parts I have on hand coupled with some parts I will need to buy. I’m open to hearing other options using the parts I already have or if the build can be done for not much more cost if I have to buy more parts. The question boils down to if a 6,000 RPM 360 roller-cam engine will get the job done well with room for me to grow, if spending a little more money on machine work to build a 7,000 RPM 318 flat-tappet cam engine will be a substantial benefit, or if going with the more expensive fully forged 8,000 RPM 340 flat-tappet cam engine is worth the extra cost. I may reach a point in skill and enjoyment where I want more power and need to build another engine, but I'm trying to avoid either spending too much up front for overkill or spending too little and not having the room to grow in skill.

I appreciate any constructive feedback those with road track experience/knowledge can give. Thanks.

 

[replicaracer43]

Option A would be my choice. The cast crank will be fine well beyond the limits of your hyd roller. You want a WIDE powerband, not a peaky one. LA 360 pistons in the magnum block will reduce or possibly eliminate the need for deck cutting. The magnum is slightly shorter than the LA, deck height wise.

 

[sireland67]

5.9 no brainer, I built one years ago.
Stock bore with hone, std KB107 pistons, stock rods reconditioned, crank turned, balanced.
Eldebrock heads, Comp 262 roller cam.
It was in a 78 W150 with 3.55 and a NP435 4-peed.

The truck had alot of torque from idle to redline and towed great.
I would build another engine like it in a heartbeat.

 

[Professor Fate]

With lots of twisties and only one straight, go for the torque of the 5.9.
One suggestion:
If your track offers a driver's school, take it. You'll get some track time with a seasoned instructor and a prepared car. You'll get to learn the particulars of the track, and see for yourself what you'll want the car to do and how it should act; and be able to plan your build accordingly. And you'll be able to network with other drivers/racers/instructors and possibly gain some input that way.

 

[Newbomb Turk]

Your driving ability and chassis/tire will dictate what your build should be.

Post 2 nailed it.

 

[go-fish]

Option A. What are you doing for rear and transmission gear ratios? OD?

 

[TT5.9mag]

From someone who road races (less frequently now than 2 years ago) in a well prepped stock class Miata, and a Porsche 911, my advice would be to buy a cheap car (Miata’s are perfect) throw a set of brakes and tires/wheels on it and go have fun. Just to get used to it and see if it’s something you’d like to pursue with an older vehicle. It will take a LOT of work to make a 69 valiant competitive. If you don’t enjoy it the Miata has good resale and you can get out fairly cheap. This plan also gives you time to develop your driving skill and you can race while you build the 69, if you decide to. My opinion only. Have fun!

 

[Kern Dog]

Competitive? What if the guy just wants to have fun and loves these cars?
That is how I am. I want to do some stuff like this eventually. I would use an A body though just because while I'd prefer a B body, the replacement cost of a 68-70 B body car is outrageous. A 73-76 A body roller can be found for well under $1000.

 

[TT5.9mag]

Competitive? What if the guy just wants to have fun and loves these cars?
That is how I am. I want to do some stuff like this eventually. I would use an A body though just because while I'd prefer a B body, the replacement cost of a 68-70 B body car is outrageous. A 73-76 A body roller can be found for well under $1000.

Fair point, although I will counter with, rarely in any kind of racing does it start with “let’s go have fun” and not end with “how can we be more competitive” or “how can we go faster?”

 

[Kern Dog]

I agree with that.
I would love to win, but I draw the line at what I'd be willing to drive to be the first across the line. I love the Mopars and do like Chevys too. I sure wouldn't want to drive a car that I otherwise wouldn't own.
What if a Saab or a Peugeot were more competitive? Those cars are hideous and expensive to fix.
It would be like boinking the ugliest woman in the bar that was the best in bed. Sure, the end results are great but all the while you're riding an UGLY horse.

 

[TT5.9mag]

I agree with that.
I would love to win, but I draw the line at what I'd be willing to drive to be the first across the line. I love the Mopars and do like Chevys too. I sure wouldn't want to drive a car that I otherwise wouldn't own.
What if a Saab or a Peugeot were more competitive? Those cars are hideous and expensive to fix.
It would be like boinking the ugliest woman in the bar that was the best in bed. Sure, the end results are great but all the while you're riding an UGLY horse.

View attachment 1716278298

Tru Dat, and the Miata is not the car to go the bar and pick up chicks in, but at the race track they womp up on much more expensive, much higher hp cars. They really can be very good.

 

[Kern Dog]

I've read that several times.
I know guys that race Mopars in road race, endurance events and drag races. They don't drive Mopars because they are dominant, they do it because they have street cars that look like the race cars and they like that.

 

[Torqueflite]

Option A would be my choice. The cast crank will be fine well beyond the limits of your hyd roller. You want a WIDE powerband, not a peaky one. LA 360 pistons in the magnum block will reduce or possibly eliminate the need for deck cutting. The magnum is slightly shorter than the LA, deck height wise.

Thanks. My hope in using the Magnum block would be to eliminate the need for decking since for this build I'm not concerned if the piston is down within reason. I'm trying to squeeze out every bit of HP, so saving on machine work lets me put more budget toward suspension, brakes, etc.

 

[Torqueflite]

With lots of twisties and only one straight, go for the torque of the 5.9.
One suggestion:
If your track offers a driver's school, take it. You'll get some track time with a seasoned instructor and a prepared car. You'll get to learn the particulars of the track, and see for yourself what you'll want the car to do and how it should act; and be able to plan your build accordingly. And you'll be able to network with other drivers/racers/instructors and possibly gain some input that way.

Thanks. Wanting the torque of the 5.9 makes sense to me with all the turns.

Great advice on the training, which I intend on doing. I spoke to the track last year, and they indeed have a handful of drivers who train either in a loaner car or in my car. I didn't consider doing the training now in a loaner since it will be a newer car unlike the Valiant, but that might not be a bad idea since I won't start building the car until next year at the earliest and probably won't be on the track until 2026. Being in the car with a highly skilled driver and being able to discuss my build can't hurt.

A good friend of mine who has pushed me in the road racing direction runs time laps in his 2020 Audi at this track, and I've ridden passenger on a couple track days with him. He knows nothing about driving a classic car, though. While I can get some good pointers from him on general driving and the track, he's out of his realm if he leaves the comfort of an all wheel drive, traction controlled car with huge wheels and brakes. I doubt he'd even drive the Valiant if I offered. He suggested I also look into joining a local club since they might have classic car drivers who train.

 

[Scody21]

Look up SVRA which is a vintage racing club kinda like NASA or SCCA. They host races all over the states and have groups for vintage T/A style cars. The issue some times with some clubs is if the car does not have any racing history and/or was not raced in period with a log book the car won’t be accepted to run. Not saying you can’t build and run the car with some local track day clubs, but if you were trying to get into events like Monterey Rolex Reunion, Brian Redman challenge at Road America or such events, your car would be skipped right over…. As many on here know, racing takes money anyway you look at it. Tires, gas, travel, entry fees, broken parts just to name a few….

 

[Torqueflite]

From someone who road races (less frequently now than 2 years ago) in a well prepped stock class Miata, and a Porsche 911, my advice would be to buy a cheap car (Miata’s are perfect) throw a set of brakes and tires/wheels on it and go have fun. Just to get used to it and see if it’s something you’d like to pursue with an older vehicle. It will take a LOT of work to make a 69 valiant competitive. If you don’t enjoy it the Miata has good resale and you can get out fairly cheap. This plan also gives you time to develop your driving skill and you can race while you build the 69, if you decide to. My opinion only. Have fun!

I appreciate that advice and get where you're coming from. While I hear you, I'm confident I'll enjoy road racing based off my motorcycle days and riding passenger at the track in my buddy's Audi. For now, I think I'll be extremely happy with competing against the clock as I learn. One of my goals of the engine options I put together in this thread is to keep my expectations and budget realistic so that I'm not too deep into funding the car if I decide it's not for me or if it is for me and I outgrow the car's capabilities. I can reuse just about all the upgrade parts on a street project and sell the car with its stock suspension for probably more than what I paid.

Have you ever raced your classic Mopar?

 

[replicaracer43]

great group of guys on this site to help guide you. I'm a engine builder by trade, and glad to offer any advice to help. I also oval track raced mopars for many years, having numerous feature wins, track championship, and a track record at the fastest paved half mile tri oval in the country. With a torsion bar mopar.

 

[TT5.9mag]

Have you ever raced your classic Mopar?

Only ever drag raced them. But my 72will be built as a corner carver. Im spoiled though that I get to drive very fast fun cars on a bunch of road corses.

 

[junkyardhero]

@replicaracer43 nailed it. WIDE powerband is where you want to be. stock magnum internals are up to the job, just meticulous attention to detail and prep. i'd talk to ken up at oregon cams and have him regrind your stock cam to spec for the application.

a magnum (or LA) can make some very respectable power without breaking the bank and live to tell the tale. i personally would build a bomb proof bottom end and spend a grip of dough doing it knowing that i could upgrade the top end later on down the line if i wanted to hunt for more power. some of the components you select can be worth 15~20 hp at a clip and that starts to add up on the bottom line. the added bonus is that some of them may be lighter than factory components as well, which can equate to a more responsive motor.

100% spend your money in the chassis and brakes. a car with good well sorted out suspension will absolutely far surpass something with 100+ horsepower. the whole: more fun to ride a slow bike fast than a fast bike slow school of thought.

 

[Kern Dog]

Only ever drag raced them. But my 72will be built as a corner carver. Im spoiled though that I get to drive very fast fun cars on a bunch of road corses.

One great thing about Road Race inspired cars is that they are still quite fun on the street. Great handling and beefy brakes make for a fun street car.

 

[TT5.9mag]

One great thing about Road Race inspired cars is that they are still quite fun on the street. Great handling and beefy brakes make for a fun street car.

My 63 falcon is a good example of that. It’s definitely not a race car but road race inspired. Turbocharged v6 Honda, 6 speed manual, coil overs, and 18x10s on all 4 corners with 200 tread wear tires.

 

[Kern Dog]

Well, THAT is an unusual build...

 

[TT5.9mag]

Well, THAT is an unusual build...

And it’s a lot of fun.

 

[273]

What Class you running in ?
What are the rules ?
One engine may have an advantage over another depending on the rules.

 

[Mean416]

I agree with @TT5.9mag

But I think it's more than being competitive. You want a safe, fun to drive car that handles well and has good driving dynamics.

This means expensive brakes, tires, cage, restraints, seats, helmets, suits, completely upgraded chassis, suspension. A warmed over 5.9 will be just fine for starters, but you will need to invest in cooling and oil control for it to last.

All this is just time and money. Just depends on how much of each you've got, really. I like the Miata idea because a lot of those bases are covered right out of the gate and you have a legendarily reliable and fun to drive car you can learn in.

Our beloved Mopars were not endowed with any kind of responsive handling in mind. So there's a lot of re-engineering required to build a fun track car.