The Official Hot Rod Thread - Part 2: No Replacement For Displacement

[ChristianPatriot]

Well here’s where I’m at, the build we’ve got going is basically a stock-ish rebuild. Around the 400hp mark. Super affordable, reliable, and tons of fun. Ridiculous bang for your buck. And I’m 99% for sure this is the right direction for me.

But....

Should I do some extra investment up front. It’ll take longer (probably a lot longer) to get together but I’ve got a running motor already in it. Forged pistons aren’t THAT much more expensive. Better flowing heads aren’t THAT much more expensive. The biggest expense would be going full roller on the cam/valvetrain. Maybe start knocking on the door of that 500hp mark. All that buy once cry once stuff.

 

[RustyHornet]

But....

Should I do some extra investment up front. It’ll take longer (probably a lot longer) to get together but I’ve got a running motor already in it. Forged pistons aren’t THAT much more expensive. Better flowing heads aren’t THAT much more expensive. The biggest expense would be going full roller on the cam/valvetrain. Maybe start knocking on the door of that 500hp mark. All that buy once cry once stuff.

I approve of this message.

 

[Brad69]

Here is my take on it.
You could build a monster for not that much more $$.
Forged pistons not really necessary unless you are gonna run NOS, Super Charge ect.
Roller valve train nice given all the trouble people have had with flat cams lately.
Heads I would get the best flowing available it's a SBC you can get great used ones for like pocket change.
BTW
Once you pass the 500hp barrier not in theory but to the ground no s%÷× for real in a street car. You become "traction limited"
Unless you have cheaters that handle funky the car can quickly become a handful.

 

[femurphy77]

Gonna have to make some tough decisions soon. How far down the rabbit hole do I want to go.

 

[churchmouse]

Well here’s where I’m at, the build we’ve got going is basically a stock-ish rebuild. Around the 400hp mark. Super affordable, reliable, and tons of fun. Ridiculous bang for your buck. And I’m 99% for sure this is the right direction for me.

But....

Should I do some extra investment up front. It’ll take longer (probably a lot longer) to get together but I’ve got a running motor already in it. Forged pistons aren’t THAT much more expensive. Better flowing heads aren’t THAT much more expensive. The biggest expense would be going full roller on the cam/valvetrain. Maybe start knocking on the door of that 500hp mark. All that buy once cry once stuff.

This is all doable. It is contingent on your budget. Again we need to sit down and look at this front to back.
As Brad mentioned you are approaching traction problems on a high order. I enjoy long burnouts next to a moon lit beach but in the end going fast is not drifting.
Is this a 10 bolt car...???
Remember....T-350. I have had them behind the engine on the stand and it did just fine but it had a few more hard parts in it. This can be addressed with little effort and just a few bucks compared to total upgrade.
Forged are always a good idea as i will be talking you into a power adder down the road. It is safe if you just do it correctly from the get go.
Build 450 streetable H.P. that will scare the hell out of most anyone riding with you. Old school comes on a lot different than the new stuff. More Visceral.
Put the kit I will suggest on it and you have whatever "Added" that you desire up to 150. Safe and easy.

"Trust" me he said.

I will help you build whatever you want. The block/rotating assembly will take 500 with no issues.

 

[churchmouse]

The edge of reality as we know it.

 

[Hop]

I'm a big fan of the PLX brand of wideband O2 sensor / gauges. I've had ~4 brands total and keep going back to PLX.
https://www.plxdevices.com/Wideband-O2-Touch-Screen-Multi-Guage-p/897346002719.htm

I'm thinking about switching over my other gauges to PLX so they all match. Right now I've got an Autometer oil pressure and Autometer vacuum/boost. The PLX stuff has outputs that I could log using my ECU software.

I'll be putting one of my old PLX WB O2 on my carb'd Honda Ruckus when I get the thing running next spring.

 

[churchmouse]

I'm a big fan of the PLX brand of wideband O2 sensor / gauges. I've had ~4 brands total and keep going back to PLX.
https://www.plxdevices.com/Wideband-O2-Touch-Screen-Multi-Guage-p/897346002719.htm

I'm thinking about switching over my other gauges to PLX so they all match. Right now I've got an Autometer oil pressure and Autometer vacuum/boost. The PLX stuff has outputs that I could log using my ECU software.

I'll be putting one of my old PLX WB O2 on my carb'd Honda Ruckus when I get the thing running next spring.

As I am truly old school () this world is new and sometimes confusing to me. Just stepping up to a 4L60-"E" with the stand alone control module (Pic above) has me cross eyed. I will get it to work but learning new things is, well, learning new things.....

 

[Hop]

From my experience, the auto-tune boxes are just meh. They will get you going but leave a lot on the table...

Once you can detect knock, see RPM, timing & AFR then you can start making some serious power. You quickly learn to get AFR into an acceptable range for the fuel you are using then start making power with timing. What you want is called MBT. Minimum spark advance for Best Torque. Pushing spark too far advanced will lose power and drive up peak cylinder pressure which could lead to pre-ignition and a pile of melted & broken parts. Running a retarded spark can push EGT way up, kill your O2 sensor, melt things & cause headers to get brittle and crack.

A common 100% throttle AFR for a factory tuned car with a knock sensor would be 10.5:1. GM called this (when I worked there), power enrichment mode. That's a real safe tune for people that might run crappy 87 octane gas. Pump 93 in my boosted car is ~11.3:1 so much leaner but less "safe". E85 burns much cooler so I can run leaner & with more boost. AFR ~11.8 - 12.5:1. Close to the same tune I used when I ran O2 sensor killing leaded C16.

Large changes in AFR do not get you large swings in power though. Timing is where you get power. You cool the charge in the cylinder with added fuel until you can run MBT without knock.

Think of pushing a fat kid in a swing. A light drizzling rain will keep you cool when you work. Pushing the kid too late and you can't get a good push. Push the kid too early and he knocks out your teeth.

 

[churchmouse]

From my experience, the auto-tune boxes are just meh. They will get you going but leave a lot on the table...

Once you can detect knock, see RPM, timing & AFR then you can start making some serious power. You quickly learn to get AFR into an acceptable range for the fuel you are using then start making power with timing. What you want is called MBT. Minimum spark advance for Best Torque. Pushing spark too far advanced will lose power and drive up peak cylinder pressure which could lead to pre-ignition and a pile of melted & broken parts. Running a retarded spark can push EGT way up, kill your O2 sensor, melt things & cause headers to get brittle and crack.

A common 100% throttle AFR for a factory tuned car with a knock sensor would be 10.5:1. GM called this (when I worked there), power enrichment mode. That's a real safe tune for people that might run crappy 87 octane gas. Pump 93 in my boosted car is ~11.3:1 so much leaner but less "safe". E85 burns much cooler so I can run leaner & with more boost. AFR ~11.8 - 12.5:1. Close to the same tune I used when I ran O2 sensor killing leaded C16.

Large changes in AFR do not get you large swings in power though. Timing is where you get power. You cool the charge in the cylinder with added fuel until you can run MBT without knock.

Think of pushing a fat kid in a swing. A light drizzling rain will keep you cool when you work. Pushing the kid too late and you can't get a good push. Push the kid too early and he knocks out your teeth.

Trust that I already understand timing/AFR and how this all relates. I do this with a carb......
EFI is a whole new ball game.

I watch the young guns sit in the car with laptop in play and it just amazes me how they tune. The results they get. And the power they are making.
It is a new age man.

 

[ChristianPatriot]

I think these would be a good option. Plenty of flow left on the table if I wanted to upgrade the cam in the future.

https://www.summitracing.com/parts/bro-1021007

 

[RustyHornet]

I reject your reality of modern technology and substitute my own.

 

[Hop]

Ricers can play that game too! A buddy's 6-second turbo 4 banger.

 

[ChristianPatriot]

Ricers can play that game too! A buddy's 6-second turbo 4 banger.
View attachment 61768

Have you seen the Red Demon? Holy cow that thing moves.

 

[femurphy77]

I reject your reality of modern technology and substitute my own.

Sweet!

 

[churchmouse]

Ricers can play that game too! A buddy's 6-second turbo 4 banger.
View attachment 61768

Rear wheel drive probably through a glide. Old and new united.

 

[churchmouse]

I reject your reality of modern technology and substitute my own.

OK so you are doing the straight axle...???


You really should.

 

[churchmouse]

I think these would be a good option. Plenty of flow left on the table if I wanted to upgrade the cam in the future.

https://www.summitracing.com/parts/bro-1021007

great set.
Now look for some forged pistons...

 

[ChristianPatriot]

great set.
Now look for some forged pistons...

Done

https://www.summitracing.com/parts/wis-pts504a3

 

[RustyHornet]

OK so you are doing the straight axle...???


You really should.