Inexpensive 350 Build

[Racer97]

Calipers should retract slightly when pressure is released. Light springs between the pads will help. Don't go heavy on spring pressure,it will cause you to have to pump the brakes to get pressure to apply the brakes.

[Nyle Green]

Nicely done. I picked up alot of good information from this thread.

If you could have a solid roller lifter or the Chinese head which one would you choose.

[F-BIRD'88]

The quality and condition of the front disc brake line FLEX hoses makes a difference also.
I replaced these on my old Firebird. Like night and day.

[tuffxf]

The secret with the brake callipers is understanding how they are actually designed to work, the parts used and the assembly method.
Extra springs are a crutch.
Dig into some old literature
Cheers

[steve cowan]

Front wheel bearing adjustment on disc brakes plays a role for pad drag.
Drum brakes not so much.
As bird said, good quality flex lines.

[vortecpro]

I'm going to follow Steve's advice and go through the system.

[vortecpro]

Nicely done. I picked up alot of good information from this thread.

If you could have a solid roller lifter or the Chinese head which one would you choose.

The point of this build was to copy our friends 350 build and see what it could do in our car, parts wise its an exact copy. We also wanted to be able to sell this engine after the test, its very mild, idles at 700 RPM with good vacuum, so that's why it was built like it was. Bigger cams, better heads would be for the next build. To answer your question, if I had to choose between better heads or cam, I'd choose a stock eliminator type cam, because it would be easy and a big power increase, but I'd be worried it might rip the rocker studs out of the head. So my plan here with this engine is too refine the rolling car and transmission and get every last bit of performance I can, and enjoy my very mild excellent running low buck 350. My Chevelle has been neglected since I moved to Tx, its time to get it out and retest every single engine combination I build in low altitude conditions on a track that caters to drag racers unlike every track in Colorado except Julesburg. We were very unhappy with the L98 heads, the Assault heads modified would have been a whole other story, maybe on the next build.

[Nyle Green]

Nice,I hope you share the the chevelle's results. Looking foward to it. Sorry about the vague question. I had a completely underwhelming vortec 350 camshaft specs of 220/224@.050 lift duration and .495/.502 lift on a 114 l.s. using the stock hydraulic roller lifters.

Your engine had a flat power curve from 5300-6300.
I noticed earlier in the thread you mentioned that you had .496 net @ the valve lift x .85 = .421 actual lift @ the valve running a hydraulic roller. That made me curious if you changed just the lifter to a solid roller would you make more power. Are you also losing duration at rpm. This might help me with my hydraulic roller engines.
Thank you.

[vortecpro]

Nyle

I don't think it would with those mild lobes, only because it was peaking @ 6300 already with the GM hyd lifters, I don't think it would peak higher with the solid roller lifter, because if you look at the graph it was done about 5500 RPM and just carried until the pumping losses showed up.I was at 160 closed and 360 open.

[289nate]

Great job and keep up the good work. I love seeing somebody who doesn’t just build an engine and think they have a race car. You are going to upset a lot of hobby types who do not understand average power and making a car work. Love following along with this and look forward to you continuing to update us.

[vortecpro]

Great job and keep up the good work. I love seeing somebody who doesn’t just build an engine and think they have a race car. You are going to upset a lot of hobby types who do not understand average power and making a car work. Love following along with this and look forward to you continuing to update us.

Update:

Preliminary carb tuning has delivered a new best 1.43 60 foot, in 1700 DA on a fair track. This was accomplished with a 750 DP in place of the original 850 DP, the 750 did lose MPH over the 850, but the 750 ran harder to the 330 foot slowing down from 330 foot on. So working with the 850 to get rid of the slight hesitation is the answer, we are working with Vintage Muscle car on this carb issue. It would seem the 750 main body would be sufficient for such a mild low HP 350, but it isn't. Interesting enough dyno testing also showed the 750 main body (950 HP) down 10 HP through out the test, mirroring what we are seeing at the track. Now the question is: if the 850 was worth MPH over the 750, is the the 1000 worth MPH over the 850? We believe the carb is the way to a better 60 foot which will hopefully get us into the high 10.70s. Next the rear suspension will have to be addressed.

[VMC]

It's always a pleasure working with you Mark, I'm very much looking forward to the next test session's results.

[steve cowan]

Great job and keep up the good work. I love seeing somebody who doesn’t just build an engine and think they have a race car. You are going to upset a lot of hobby types who do not understand average power and making a car work. Love following along with this and look forward to you continuing to update us.

Update:

Preliminary carb tuning has delivered a new best 1.43 60 foot, in 1700 DA on a fair track. This was accomplished with a 750 DP in place of the original 850 DP, the 750 did lose MPH over the 850, but the 750 ran harder to the 330 foot slowing down from 330 foot on. So working with the 850 to get rid of the slight hesitation is the answer, we are working with Vintage Muscle car on this carb issue. It would seem the 750 main body would be sufficient for such a mild low HP 350, but it isn't. Interesting enough dyno testing also showed the 750 main body (950 HP) down 10 HP through out the test, mirroring what we are seeing at the track. Now the question is: if the 850 was worth MPH over the 750, is the the 1000 worth MPH over the 850? We believe the carb is the way to a better 60 foot which will hopefully get us into the high 10.70s. Next the rear suspension will have to be addressed.

I have found on my 383 engines the 950 hp carb 60 ft and ET the best as well.
The 950hp carb responds more as well with mufflers on/ off as in fuel curve and needing more jet with open headers.
At WOT it pulls 0.75" vacuum across finish line so that could be a restriction.
With my 4150 QFT 1050 carb with annular boosters manifold vacuum is 0.20" at WOT .
60 ft is always down slightly doing back to back at track testing. 1.43 (950hp) - 1.46 (1050) carbs.
ET is near on the same but around 1/2 mph at the long end in difference.
Mark are you playing with spacers on top of the airgap intake? Or are you in stocker trim.
Appreciate you posting your results, always plenty to learn.

[steve cowan]

20240103_132344.jpg

20240103_133322.jpg

Black line is without drop base lambda was 0.86 and sounded rich coming into the pull.
Fitted drop base no other changes is red line.
Lambda back to 0 91,engine was not choking on the fuel ,best power run of the day with 1050 carb on a 2" 4hole tapered spacer.

[skinny z]

Update:

Preliminary carb tuning has delivered a new best 1.43 60 foot, in 1700 DA on a fair track. This was accomplished with a 750 DP in place of the original 850 DP, the 750 did lose MPH over the 850, but the 750 ran harder to the 330 foot slowing down from 330 foot on. So working with the 850 to get rid of the slight hesitation is the answer, we are working with Vintage Muscle car on this carb issue. It would seem the 750 main body would be sufficient for such a mild low HP 350, but it isn't. Interesting enough dyno testing also showed the 750 main body (950 HP) down 10 HP through out the test, mirroring what we are seeing at the track. Now the question is: if the 850 was worth MPH over the 750, is the the 1000 worth MPH over the 850? We believe the carb is the way to a better 60 foot which will hopefully get us into the high 10.70s. Next the rear suspension will have to be addressed.

It may seem a naïve question however I'd like to know what you attribute the differences in performance between the carburetors tested?
Is it simply a fuel curve thing? Or signal and responsiveness? CFM?
If I recall correctly you don't do any datalogging. So is it then a matter of swapping carbs and looking at the results?

Following along with your post above, I'm also very interested to see what you do to the 3rd F-body rear suspension.