How to Get More Horsepower (& Torque!) Out of Your Classic Car Without Expensive Modifications!

Learn more about how to tune your classic and a few tricks of the trade by watching me discuss a few items on my 1970 Chevrolet Caprice.

[timferguson]

A friend of mine had a 68 Impala. 427 travertine he would try to bury the accelerator the 2 back jets never kicked in. We couldn't figure it out. All afternoon we tried everything. Then his little 88 yrs old grandmother came out took a look and told him not enough travel in your accelerater. She took a wrench made a couple of moves and wala, the back jets jumped to life. She was a mech in the WACs during WW II

[jeffsmith]

I have one item that you did not mention that is very important to HP and mileage. The distributor vacuum advance on almost every old car has a ruptured rubber diaphragm inside and is not advancing the timing when needed. You can easily test this just by blowing on the vacuum line that goes to the diaphragm and see if it offers resistance. Or put a hand operated vacuum pump on the line to the vacuum advance and pump it up and see if it holds vacuum (it should)

[tombrown]

The air cleaner trick worked like a charm on the family Oldsmobile. Don't know what HP increase it yielded, but when you tromped down on the gas, it sounded cool as hell!

[scarbourgeoisie]

Saved the best and cheapest trick for last. I remember when this car was in the Oshawa area, I’d see it at local car gatherings. It is a stunning example of cars of this era and is as beautiful in person as it looks in this video. I’m glad Adam took the chrome Canadian Tire exhaust tip extensions off of it and made it look more stock. It was the only downside of the car and it’s been corrected.

[mdogg]

Also, if installing a dual exhaust, consider a cross-over pipe to balance the flow. BTW, beautiful car!

[paulr]

The good old days, big V8 engines in big cars.

[Vampirebear]

Horsepower was massively underrated in the late 60's, plus HP dropped when they went from leaded to unleaded gasoline.

[Johnnycdrums]

Excellent tutorial.
Love that interior too, you can tell only clean people rode in it.

[DanEBoyd]

The 390 horse offering was the LS5. The LS6 had 450.
So were the factories sending these cars out the door with the compromised throttle linkage adjustment, or was that something mechanics did during the gas crisis?
Love the fender skirts on there!

[marlins]

Hi Adam,
I think very highly of your channel - all the high-quality history lessons & perspective. However, let me suggest if you're bringing attention to power & efficiency upgrades, please don't forget BRAKE upgrades.
As a friend in the Plymouth club once said, no matter how well-maintained your antique cars' brakes are, in today's modern traffic, there will always be someone in front of you who can stop sooner.
As someone who can attest how inadequate certain Mopar brakes were, please relay your knowledge of disc-brake replacement kits.
I can speak favorably about ScareBird, if you don't mind.

[barneymiller]

We used to love the "shooomWaaa" from flipping the lid on the QJet!

[jimato]

A 454 Caprice ! Stunning, just stunning and rare. This is a nice addition to your stable Adam.

[DavidPysnik]

Good tips here. The throttle linkage can definitely be an issue, though it is not necessarily as easy to fix as shown here depending on the car. I have a Cadillac with an Olds 307, and that engine needs every ounce of power it can produce. After buying it, I discovered the throttle cable had stretched and wasn’t really adjustable, so I used a spacer at the gas pedal to tighten it. It made a huge difference once the secondaries could open up all way and the transmission cable was also adjusted. I also did a timing adjustment, which also helped greatly. That engine will never be a beast, but it was much more enjoyable to drive with nice low-end torque and could actually pull uphill decently with no trouble keeping up with traffic.

[Dr_Reason]

Pre catalyst unleaded cars often had stiff advance springs with a high travel vacuum advance. Softer springs and an older short travel advance can can add a lot of midrange pep to the low compression 72 to 75 models.

[radioguy]

a true dual exhaust upgrade on my 66 Mustang GT was stock but when I upgraded to smooth bend 2.5 inch flowmaster pipes over the rear axle I picked up 5 ! mph in quarter mile trap speed, also a multi spark ignition box on a 427 boat engine I worked on made it start instantly a huge improvement over the dual point mallory set up, highly recommended and cheap . one more thing you didnt mention was these cars all had huge rear gears and a redline synthetic differential lube change will give a noticable improvement . really noticed it on my Ranger 2.3. reason is gears like these have sliding friction and lots of it .

[willallen]

My buddy had a crafty machine shop steal his '70 LS6 heads, he bought the LS6 in pieces and took it to them to assemble. Year or 2 down the road he misses a gear going downhill and floated the valves with the expected results.
So in the process of inspecting the damage I pop the intake off expecting to see those beautiful huge rectangular '70 LS6 intake runners, imagine my shock when I was confronted by oval "peanut head" passenger car intake runners.
He was a hot rod user not a builder so I actually had to explain to him and argue with him that he's been robbed. When I finally got him up to speed he calls the machine shop and ofc they are closed.
My opinion for the HP increase is a head swap and tighten the nut behind the wheel.

[flexjay]

Such a great car, and some good tips on proper running. I had a '68 Impala back in the 70's, and would love to have a new one !

[tonyflorio]

When i was a kid, my folks bought a 1970 Pontiac LeMans Sport with what our mechanic called the "American" 350 2bbl (we are in Canada so most Pontiacs until then had Chevy engines). He asked my Dad if he wanted a bit more pep and advanced the timing as outlined here and told him to run premium gas. Ran it like that until the advent of unleaded when many stations took away premium as they needed the extra pump for unleaded fuel.

[AbcDef-iqno]

That Caprice is such a pretty car. When I wasa kid some neighbors bought a brand new 1970 Impala two-door and it was a stellar car.

[Kizzle]

I was happy to see this in the garage during your last Lincoln video. Great info as always and thanks for keeping the classics alive.