Engine overhaul

 First question is what is your desired horsepower? 

 First bit of advice is to not bore/drill the cylinders any larger than absolutely necessary.  The maximum should be 30,000s of an inch, but do not let your engine builder just do that as a standard approach. Keeping the cylinder walls as thick as possible is important for engine durability. You might need custom sized pistons but it doesn’t sound like you are on a restrictive budget  

 With your research you likely have some basic guidelines established. What are they? 

 Carburetor or EFI ?

 Flat tappet hydraulic cam shaft or hydraulic roller or solid lifter ?

stroker engine?

 Iron heads or aluminum ?

Intake manifold short enough to allow use of engine screen or are you willing to discard/modify the engine screen?

 If you are seeking specific recommendations we need to better understand what you anticipate building 

Larry 

Andreas, I think you need to think about the look from your new engine. Should it look stock and should it be a "better" original motor or something special modern?

For the 3.77 gear , I would go with a stroker 393 kit . You can use your 4V heads , but they are a lot of work to make them going. Mill the pedestals and some port work is in my opinion the way to go.  Stay at about 10.7 : 1 compression rate because of the thin block walls .

TM makes nice stroker kits , also I love the nice pistions from him.  He done a internal balanced kit for me and it was realy nice.

When you stay under 6500 rpm a restricor set for the oil is enough.

Better is to bush the lifter holes.

Where are you located ?

Sorry, I have probably not given enough information. I want to keep the original look, no injection system, carburetor. I would like to use the existing 4V heads or the Aussie heads. The original engine cover should still be usable without modification. Regarding the topic stroker, I do not know very much about that.

@gt4peter, I‘m located in Germany

Thank you

Andreas

I assume your 4V heads are open chambers?
You can keep them but you need special pistons to obtain a sufficiently high compression ratio. You should also know that it is more expensive to have them modified to fit roller rocker arms, bronze valve guides, stainless steel valves with good springs, than to buy ready-made aluminum cylinder heads.

You haven't told us if you want to build your engine yourself or have it done by a professional? If you want to build it yourself, you should know that there are a lot of parts to choose and buy in the US and it takes a long time.

Do you have read the threads of Georges on the forum, it's a very precious mine of informations:
https://pantera.infopop.cc/top...d-performance-tuning
https://pantera.infopop.cc/top...mber-4v-heads-q-code

Here is the configuration of the engine I am building myself:
- original block 4 bolts reamed to 4.020 "
- forged Scat crankshaft 3.75 stroke (383 CI)
- 6.25 " Scat I forged connecting rods
- Rosspiston custom forged pistons
- Original heads with ports slightly ported by me and bronze guides
- Special Bullet camshaft according to Georges specifications
- hydraulic roller lifters
- Compcams roller rockers
- Ferrea and Manley stainless steel valves

- Holley 750 cfm #9379 annular boost

- Blue Thunser intake manifold

- europa GTS headers

It is also necessary to install liners in the tappet bores to improve the lubrication of the engine (Wydendorf Machine)

The block and cylinder heads are currently with my machinist for the reaming and installation of bronze valve guides and the modification of the pedestals.

I have a transmission with the original ratio of 4.22 / 1

Hello, Rene,

yes, they're open chamber heads.
First of all thank you for the information to everybody. Yes, I read the articles. That is the reason for my request here in the forum. There is so much information that I am overwhelmed with it. I would like to build the engine myself, I have professional support. I also have time, because my Pantera runs perfectly with the crate engine. I am only unsure which components I should buy and which combination harmonizes well.

Thanks
Andreas

Andreas, nice to meet you here ! I am located in Austria / Vienna.  If you need any help please fell free to ask via pm .

Andreas hi

I can talk you through the document from George, as I used it to overhaul my engine. It is not so complicated just a decision making.

Well I used modern alu heads due to cost..(ref René above)

regards from Stuttgart

Matthias

I suppose if you want to reuse the iron heads it is to keep the original appearance? So you stay with a carburetor feed?

To choose the right configuration, I think you need to set a power and speed target. With a ratio of 3.77, I think the maximum power at 5500 rpm would be good, it would be around 85, 130, 180, 225 and 270 km / h on the various gear.

With my configuration, Georges thinks that I will have 490 hp at 6100 rpm but I will already be happy if there are only 450.

If that helps I can communicate to you by PM all the references, the suppliers and the prices of what I have chosen.

Hi Rene, hi fellow members,

I'm also rebuilding my engine and thinking about getting a stroker kit from SCAT. I'm undecided between the 383 CI and the 393 CI assembly. Why did you choose the 383 CI?, Why did you prefer Ross pistons over the AutoTec ones supplied with the set? Did you need a camshaft with a small base circle for the necessary clearance?

THX, Carlo

Note that it’s easy to lose horsepower in your exhaust system, and some of the more common offerings can be restrictive.

Think about the trade-offs there too.  

Rocky

I took a lot of advices from Georges because I am not a motorist but I was an engineer and his explanations seem to me all to be coherent from a technical point of view.

So, 383 CI rather than 393 to have a shorter stroke, therefore a smaller rod angle and therefore less stress on the walls of the cylinders which are THE weak point of the Cleveland blocks.

RossPiston pistons, always following George's advice, except that the custom pistons that Rosspiston delivered to me don't have the full circular skirt !!!

I contacted them and they told me that even in the case of full skirts, the pistons being very slightly oval, the skirt does not press on the cylinders walls and the pressure is not reduced. George's explanation would therefore not be good according to the brand he recommends ??? I admit that I don't know who to believe, even if Rosspiston's argument seems valid to me.

No camshaft with reduced base circle because the crankshaft outside diameter   is roughly the same as the original; the stroke is increased by reducing the diameter of the big side of the connecting rod, 2.10'' instead of 2.31'' for the original ones (Chevy SB rods)

This option I believe came out after George's recommendations. 

https://www.tmeyerinc.com/prod...sembly-351c-stroker/

This "centralign" design supposedly helps with some of the rod issues while dealing with Chev style rods in particular. Tim has helped with quite a few very nice Cleveland builds, I plan on trying his rotating assembly when I start my build.

It sounds interesting and the price is reasonable.

Thank you for the information. Beautiful pistons!

Cheers, Carlo

Interesting. Why would Chevy rods be offset from the piston centerline, I wonder?

Maybe a topic for another thread. 

I stayed away from a stroked engine due to the complexities of the parts selection. An engineered kit like that would have given me more confidence, especially if you could talk to the kit supplier, and he had good answers to all your questions....

Rocky

Honestly I used the "George formula" with stock crank and rods, ARP rod bolts and Wyendorf lifter bushings, Ross pistons, Trick Flow heads, my engine runs fantastic and makes more power than I can really use on the street.  I do however run 180 degree exhaust so I don't think the exhaust is creating much of a bottleneck.  I did the rebuild work myself minus the machine work of course.

I very much believe in George's formula, especially with stock crank and rods, and think the lifter bushings are a must. What I am saying is that I think this rotating assembly takes care of some of the other concerns that George has mentioned before in regards to strokers if people are choosing that route.

I have owned two or three cars with a weight / power ratio, driver included, of 3kg / hp and I wanted at least as much with the Pantera, so I want around 450hp but without having to run too fast, hence the choice of a slight strocker which, according to George, saves 500 rpm.
I chose to keep the iron heads, even if they are a little more expensive and maybe work a little worse than modern aluminum heads, because I like the idea of the rustic american engine over 50 years old , all in cast iron, which still produces not far from  80hp per liter (80hp / 61 CI).