I have a new question but don't want to open new threats every 5 days.
I hope somebody reads this.

I made a list with the parts I want to change/swap to make my newport faster.

For the heads and cam I want to take the engine out. When it is out I can change some other things. Should I get a lighter flexplate or something?
For the record: I want to have more torque and more acceleration. But more power in higher rpm's isn't a bad thing.

First of all there is nothing wrong with the less expensive Edelbrock heads for street use. You are not planning ultra high rpm or huge valvespring loads. They will flow plenty of air for a 400.
The stock compression ratio is a lie. Chrysler usually shipped their engines with between 1/2 and 1 point of compression less than advertised.

Using a Sealed Power piston compression height of 1.812", a stock 92cc head and a stock thin steel shim head gasket your compression calculates to 7.5:1.

Change to a 75cc Edelbrock 5090 and the same head gasket and your compression increases to 8.5:1. That is a significant increase. The compression ratio determines thermodynamic efficiency.

Stock head gaskets were steel shim, about 0.020" (0,5mm) thick. Many have used them with aluminum heads.

The LaRoy Engines advice is my thought, also. I would have picked the next larger camshaft, but it's hard to argue with the dyno numbers that they posted. It is very easy to put too much camshaft in a 383 or 400.

That camshaft seems to me to be a modern version of the stock HP engine camshaft. It will run with all stock valvegear in most cases.


The Lunati Voodoo cam line is very good. They use a 3-bolt cam drive gear, so you need to add a 3 bolt timing set to your list.

There isn't a lot of mass to take out of a flexplate, it isn't worth doing.

When you add headers, your carburetor will need to be adjusted. It is usual to have to increase carburetor jet size when adding headers. An air-fuel meter would help.

It helps power to have an H or X pipe system. The easiest is usually the H-pipe, which Mopar engineers used. The pipe connects both sides of the exhaust system and is usually installed where it fits best. The X-pipe adds complications and will require more work to install.

Your car will be more responsive with a high performance ignition curve. Stock curves brought spark advance in very slowly. High performance curves increase spark advance more quickly. You will also find that you get maximum power with total advance of 38 degrees, plus/minus a few. I understand the Firecore distributor, made by a Board member, has an ignition curve that's very easy to adjust. Stock distributors tend to have too much total advance and require much more work. There are other distributors with adjustable curves as well. Do not buy a no-name distributor on Ebay, or a Summit or Jeg's brand distributor.
R.

Paddel, maybe I missed it, but what model car is your 400 engine in? Just curious. How much does it weigh?

Okay thank you for your infos dogdays. I already did the distributor.
I want to add headers at last (maybe before converter change). I want to change my Thermoquad for a HP Thermoquad from a 440 and adjust it.

@D_C: it's a 1974 Newport. On the internet it is said to be around 4600 lbs.
I had to weigh it to register it but I don't know where the papers are.
But it's pretty heavy...

On paper. In real, no. See dogdays' post for some good info on this.

Yes, factory compression ratio can be a bit variable on a 40 year old production engine.

Lots of good advice so far. As suggested, total performance involves the entire car and sometimes you get greater performance improvements for money spent, from drivetrain and chassis components instead of focusing entirely on the engine, in getting the most performance for the money and effort expended.

Also, when you significantly improve engine performance, other parts of the car start to bend and break. Chassis twist, differential ring gears, u-joints, etc, break.

I went with Edelbrock Heads on my 440, but that was over ten years ago now. I have been happy with my choice, but as suggested, increased compression is like (relatively) free horsepower.

good advice. I already rebuilt my suspension.
I will change my third member with the new gear ratio (make al bearings new).
Maybe get a swaybar in the back.

I will also built subframe connectors (is that the right word). My dad and I are good in metalwork. I stiffened a Ford A 4 cylinder Frame to hold a 500 cui Cadillac Engine and it does not twist a bit and is still light (the car has 1200 kg).
I hope that the Alu heads reduce weight a bit (that I can feel it).
I don't know the right technical words but I lowered the car by screwing down the front suspension. So I put tension in it. It's bit hard to explain for me but I think you know what I mean. It's lower and harder.

The brakes work wonderful.
I thought about a alu drivetrain and third member. But that car will not make enough horsepower to notice (I think).

I write this all down to see if I am eading in the rigt direction, not to show ow smart I am

Thank you guys for your help

You'll wanna redo the dist when you get the eng running with the new swapped parts: heads/cam etc. Get the the mixture ballpark close then fine tune dist subsystems in order: initial/total/springs/can (if used) then fine tune the mixture with an LM1

You are doing fine. Those are the right things to be doing, such as subframe connectors and component upgrades.

About lowering the front end however, from all I have heard and read, lowering the front end by torsion bar adjustment...

A little bit is fine, but there is a point at which the suspension geometry is off, parts wear rapidly and it becomes difficult to maintain wheel alignment.

The Brodix B-1 B/S heads have 65cc chambers which would bump the compression up, but they do use an offset intake rocker arm. I'm still waiting to see the Trick Flow Power Port 240 Big block Mopar head?

The Brodix B-1 B/S heads have 65cc chambers which would bump the compression up, but they do use an offset intake rocker arm. I'm still waiting to see the Trick Flow Power Port 240 Big block Mopar head?

@D_C: that's right. I controlled that when I lowered the car.

So I'll go with that plan.

I just wanted to know another thing. Some people said, that I should use other pistons for some more compression. Are there any with just slip in and are usable with my stock parts (like crankshaft, conection rods...)

I thought that I should use new bearings and such and for that I have to take the engine apart. And when theres some money left I could use new pistons. But they have to work with the e-street heads and my stock parts.

But the pistons are not in the plan yet.

You are correct. The Firecore Distributor is extremely easy to dial in. We also have the last of the Mallory super-tune kits for the Mopar Distributors. Kit includes 9 springs, timing curve keys, and directions. I bought all that Summit had, FWI.

So long as you check with the piston manufacturer to verify, there should be Pistons that can be used with Original Equipment Factory components.

When you use aftermarket Pistons that increase compression, it is typically a good idea to check clearances to make sure that the valves are not going to hit the Pistons.

You may be able to use Modelling Clay to verify clearances.

You live far away and everything that you do should work right the first time. So I'm not in favor of anything that is too complicated.
Also, you are talking to a bunch of racers here and they will suggest race parts. For example, B1-BS heads are race heads and are not a true bolt-on. I don't believe they can use your stock rocker arms and pushrods. They also require a bit of machine work and setup, more than the Edelbrock heads. Forget them.

IF you are planning a stroker down the road don't buy a set of different 400 pistons at this point. Again, it's not worth it. Do whatever it takes to get to the next performance level and enjoy driving the car. I have projects that I got trapped in the "as long as I'm doing this..." syndrome. They are still not done after years and years. I do not recommend this approach for others, having learned the hard way myself. I have a garage full of parts that are now obsolete because of new improved designs. If I'd put them together when I bought them it would be okay. But now using them doesn't make sense. And nobody else wants them either.

I trust you can do all the structural work to the car yourself, or get it done. It is more fun to drive a car if it can go around a corner at speed. Same with stopping.

Your suggested engine modifications should increase power by 35% or so. That's noticeable.

Another thing, I doubt that you'll notice a difference between the large or the slightly larger Thermoquad. Both are large enough for your projected power level. If your carburetor works now, I'd suggest putting money into tuning it, rather than replacing it with another 30+ year old carburetor.

I have a wall full of carburetors and they are becoming less valuable as time goes by. A self-tuning fuel injection system is easier and better for 90% of the people who are still using carburetors.

Best Regards,
R.

Here's an example of a piston that'd replace a stock piston and increase compression while using all the other stock parts. The Keith Black KB240 has a compression height of 1.908 and will increase your compression ratio by nearly 2 points. It has huge valve notches which will swallow any extra lift you are planning. They are close to stock weight so no rebalancing required. Campbell Enterprises has them with new rings for around $520.00, but if adding pistons one really needs to bore to the next oversize which adds another $200 or more, plus cleaning the block, $100, plus pressing pins in and out which adds at least another $100.

So with the small chamber Edelbrocks you are looking at around 10.5:1 compression, will still run on pump Premium, but it will cost you at least another $900 plus shipping. This would be a really nice engine, and if you went that way I'd suggest the next larger Voodoo camshaft. You may not need to do anything else to the motor. It'd make an easy 440 or 450 hp.

Choices, choices.......

@dogdays: what you are saying makes really sense. and it's true. almost nobody here is an expert with those us cars.
the 10.5:1 compression sounds really nice and 450 hp would be more than enough.
But maybe, when I am done and drove the car a bit, I want even more.
It is really really hard to choose.
In the end it's a money thing. as always

Here are a couple of links that are related to your build. This shows the engine as I had it built and has a link to the original buildup. Short story, a simple steel 383 crank/ stock rod/ KB piston 9.7:1 shortblock with the smallest Comp Thumper cam. With stock 906 heads, RPM intake 750 Holley it made 427 HP 443 Ft/lbs. Mildly ported RPM heads 1.6:1 rockers Offy tunnel ram and a pair of AVS carb it made 472 hp 489 ft/lbs. Same basic build with a larger solid cam Victor heads bigger carb 1.7:1 rockers 507 HP 470 Ft/lbs. The compression was higher with the Victors due to the smaller chambers.

wow. those are really good numbers.
I am really looking forward to finishing the built.
Maybe I'll get the KB pistons. Seems they will add much more power.
When finished it will be a really smooth car.

I want to do the engine changes this winter.
with this parts:

-Edelbrock 5090 heads
-Lunati Voodoo 10230701LK cam
-keith black kb-240 pistons

and of course everything around (timing gears & chain, gaskets, pushrots....)

It was mentioned to use the 10230702 isntead of the 10230701 cam. But on the Lunati Homepage they say that the 10230702 needs improved valve springs. But I don't know if the springs on the Edelbrock 5090 heads can take it for long.

Also I maybe want to add an Edelbrock E-Street EFI because it automatically adujsts, I can set the fuel-gas-ratio for WOT etc., it will start even if it's really cold (it gets cold here) and just for the reliability.
But will that steal some Power or is it just plain stupid to do that?

Answering the last question first: It is just plain stupid NOT to use the EFI. Sure, a tuning maven might be able to tweak a carb for more power but I doubt you will have luck finding one on the Continent.

Board members who have made the switch are unanimous or nearly so that it was a good thing to do. If you can afford to do it, why not? And especially with European fuel prices.

On to the camshaft: The Edelbrock springs part number 5792 should be good for a hydraulic flat-tappet cam up to at least 0.600 lift. They are very close to the Lunati suggested spring for the 02 Voodoo cam, actually will have a higher spring load across the range from full open to closed. So there would be no reason to change the springs. I'd like the 01 camshaft better if you're doing a lot of stop and go driving, it'll have quite a bit more torque at low rpm, say until 2700rpm. After that the 02 cam may be better.

The 01 cam is quite similar to the 440HP camshaft, and that used to be the ticket for a 383, use the carb and cam from a 440HP_ engine in a 383.

In conclusion, the 383 is very easy to overcam and the good cylinder heads make it unnecessary to use such a big cam, so I'd stick with the 01 cam.

Think about the newest American V8s making really good power with camshafts that range from 197 to 211 degrees at 50 lift on the intake. That's because the heads flow so much better.

One more thing, the Voodoo cams are three-bolt cams meaning they need a 3-bolt timing set.

R.