Rebuilding the engino on my P20

[Guest labaglia]

Hello everyone

This is the second time I write on this post, the first time everybody here has been very helpful in helping me find out that one of my rear axles was too short ....

After a summer of seldom driving due to excessive oil burning I even got pulled over by the cops.. thank god I was not driving a 92 civic cause they would have showed no mercy.. ) I finally took the decision of taking the engine out for a rebuild. I already know I have no compression in one of the cylinders and new rings gaskets etc.. are guaranteed to be changed, I will also check the transmission at the same time of course..

I will take my time during the winter, but here is were I would like your help :

Since the engine is out already I would like to try and get a couple more HP out of it.

So what can you suggest as simple mods that coud get my L6 a little more performant? Do you know if there are "performance" parts for this kind of engine ?

Thanks

[Jim Saraceno]

It seems to me that in a former dicussion on this forum, the best way to get more power is to use duel exhaust and duel carburetors. You can also shave a little off the head to make higher compression.

Some will also bore their cylinders out to .060" to get a little extra displacement, but I would think that would make that much difference.

[greg g]

If you look at the spec sheets on flat head engines from the early 40's through the late 50's you will note that the compression ratio went from 6.1 to 1, to 8 to 1 in 1959. The HP rating on the 59 engine was 135. So if you are looking for more umph squeezing the air fule mix tighter makes for a bigger bang. It has been suggested that you can remove .090 in from the head block area and still run regular gas. Additional removal of material will require premium fuel. When I did my engine the machine shop removed .040 from the head, and .010 from the block. With .030 oversized piston the numbers calculate to about an 8 to 1 CR. I am also running dual carbs but I believe the bulk of the increased power comes from the higher compression ratio.

Putting more fuel/air into the stock compression ratio won't yield much increase in HP

[Normspeed]

The only thing I might add to the above suggestions would be, while the engine is at the shop, have the cam reground. Good time to have that done, and it will compliment the less restrictive dual intake and exhaust.

With those changes on a fresh engine, you'll have a nice perky little 6.

[Guest labaglia]

Thanks

i knew that I would get good suggestions here!

Can't wait for next summer!

Anybody knows were is the best place to look for the ontake/exaust an carbs?

Are there any online stores that sell them?

Thanks

[Don Coatney]

Anybody know were is the best place to look for the ontake/exaust an carbs?

Are there any online stores that sell them?

Thanks

Contact George Asche. Not available on line. (814) 354-2621

[Normspeed]

I got my offy dual intake manifold from Car Products, PO Box 96, Paragonah Utah 84760, 435-477-8213. The manifold with fuel line kit and linkage kit was under $250. He also sells the correct size air filters (2 5/16 carb flange) for around $10 apiece.

Carbs, you already have one, and for the second one you can find them on ebay frequently. Rebuild kits are available and cheap.

Split exhausts you can either buy a stock one that's been split, like mine, or Fenton style headers already made for duals.

[48mirage]

I bought a '49 D30 all stock. I picked up an intake and exhaust manifold from a '54 plymouth. I had the exhaust manifold modified for a second outlet. I did not seperate the 2 halves so the heat riser still functions. For carberation I had an adaptor made from a piece of aluminum and installed a holley 94 2 barrel carberator from a '56 Ford. Mounted 90 degrees from the original position I was able to use my existing throttle linkage with only a minor adjustment to the length of one rod. I chose this particular setup becuase I could use the exhaust manifold heat tube for the choke on the Ford carb. About any Holley 94 with a manual choke would have been just as easy. This made the linkage and intake mods very simple (and cheap). It really woke the gal up. I also picked the head from the '54. It was the later head and was already higher compression but I had it milled a little more. I have not installed it yet. When I open it up I expect I will find other things that need attention and I want to be prepared for them when I get to that point.

http://www430.pair.com/p15d24/mopar_forum/attachment.php?attachmentid=2420&d=1180732703

[hkestes41]

I bought a dual Offy intake and cast iron headers and HEI distributor from Langdon's. http://www.stoveboltengineco.com/ Don't have them on the engine yet will be doing that in the next month or so.

[Normspeed]

48mirage, I like your car. That's a slick installation on that carb. HK, you got a real good price on that package, didn't you?

[hkestes41]

48mirage, I like your car. That's a slick installation on that carb. HK, you got a real good price on that package, didn't you?

Yeah Norm, it wasn't too bad. It was $1200 including the ceramic coated headers, header flange and seal kit, heat plate, intake, carb linkage, new carter/webbers, carb adaptors, air cleaners, HEI, high voltage coil, spark plugs, and side covers.

Tom Langdon was very helpful when I talked with him and was a wealth of information. It was also great getting everything in one place. I had found bits and pieces of the package at a little lower prices elsewhere. But when I started looking at the hassle of multiple orders and shipping costs from several places just didn't make sense.