454 engine up date
Thread Starter
2nd Gear
Joined: Jun 2012
Posts: 2
Likes: 0
From: Brasilia
454 engine up date
I have a convertible 74 , manual gear , 454 Vette in Brazil , and I know due the Petrol crisis in 70 years , the factory turn this big block in docile cat … what can I do to turn this engine In a tiger ? The 1970 ( same block ) it’s a real tiger right ? What’s the shipper change Can I do ? I need help !
best regards
best regards
Melting Slicks
Joined: Sep 2007
Posts: 2,147
Likes: 284
From: cary Il
there basically the same engine, 70 had a little more compression, best upgrade is a lower rear end gear change, if you want more pop
make sure its tuned up well, secondaries are opening, timing set a little aggressive, things like that
make sure its tuned up well, secondaries are opening, timing set a little aggressive, things like that
Thread Starter
2nd Gear
Joined: Jun 2012
Posts: 2
Likes: 0
From: Brasilia
454 Engine up date …
what’s best way ( and simple and shipper ) to increase HP in 454 , manual gear ?
Old Pro Solo Guy
Joined: Dec 2017
Posts: 8,033
Likes: 4,388
From: Marlton NJ
- More compression - 74s were low 8s, you want 10.0 to 10.5
- More cam - factory cam was really mild - something in the mid 220s to 230 max duration at .050"
- More rear gear - 3.23 is good for a BBC - you don't really need more
- A new trans - a standard close ratio 2:20 trans is just too tall, but a wide ratio 2:52 is much more lively, but an old factory muncie wide ratio will barely stand up to a BB. I would strongly consider a custom 4 speed with a stronger case - it's called a M23 autogear - or a TKX 5 speed overdrive - but the 4 speed is much cheaper and all you need in town
- heads, intake, carb are all less important than the above, the Q-jet carb is actually an excellent piece. ok get rid of the EGR intake
- Your factory ~330 HP will jump to around 450+, and TQ will be 500+
- good exhaust & headers to let it breathe, it pumps a lot of air
- AFR heads if you have the bucks, 80+ HP on top of the above factory heads
Last edited by leigh1322; Aug 12, 2022 at 09:26 PM.
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
how easy is it to get engine parts in brazil? i know people in europe and australia have a very hard time, long wait, high import duties. i think timing it correctly and a good exhaust system is your first step. timing is free. long tube headers and 2-1/2 exhaust is next most important. and anything beyond that, better heads, more aggressive cam, intake, etc must have the exhaust upgrade in order to be worthwhile. get a good timing light and make sure you have 36-38 degrees of advance with vacuum advance not hooked up when the timing stops advancing with RPM. usually around 3000 RPM, but it could keep advancing at higher revs if springs are too stiff or weights too light or hung up. in fact, make sure advance weights move freely before doing anything else. timing at idle is the quick way tune up shops check and they assume the advance is correct after that and the factory timing is designed for emissions. not performance.
Team Owner
Joined: Jul 2004
Posts: 40,359
Likes: 787
From: Redondo Beach, California
I think the 454's really respond to...air. New technology aluminum cylinder heads. I really like the aluminum heads because they drop ~100 pounds of dead weight off of the front of the car. A modern design aluminum intake manifold. A cam shaft with a little more duration and higher valve lift.
For an education, I recommend watching the Youtube videos of Richard Holdener. Look at some of his many videos of testing various combinations of Big Block Chevy engines. BTW...I speak perfect English, but Richard talks too fast for me. I always watch his videos at 0.75 speed!
As for Big Block heritage, you have a Gen IV BB.
For an education, I recommend watching the Youtube videos of Richard Holdener. Look at some of his many videos of testing various combinations of Big Block Chevy engines. BTW...I speak perfect English, but Richard talks too fast for me. I always watch his videos at 0.75 speed!
As for Big Block heritage, you have a Gen IV BB.
