2 brl carb and hopping up engine

[Lou Earle]

" In 1956 Plymouth offered a 2 barrel carburetor option which gave about 8 more HP over the standard single throat. A less restricted exhaust would have probably yielded a similar amount. " Per Greg in earlier posts on split manifolds.

Now that I have run the daylights out of the engine in my 48 4 door taxi ( I have been flagged down a lot in Dublin Ga people wanting actual rides!) guess what. After sustained driving at over 55 mph of about 8 or 9 hours now ( speedo broken you know) it Idles and runs great burns a quart about every 300 at over 60- just like they did when new.

So- here is the deal I want to budget hot rod it!

I have the following:

2 Barrel intake off of something

Asche split exhaust

Unmilled head- It is unmilled isn't it Tim?

Anyone got any Ideas what carb the 56 used? or any suggestions for a replacement- Webber??

All suggestions welcome

PS Also are these mods possible in the car? I am wondering how in the hell to get to those manifold bolts.

Lou

Lou

[Lou Earle]

To get 8 to 1 compression how much to shave off head?

Lou

[greg g]

I believe the carb was a carter BBR similar to the ones on the small v8s from MOPAR. You could also get one of those carb adapters from langdon's and run a carter webber like Blueskies has (also from Langdon)

As for CR if your head is a stock P15 at 6.7 to 1, you probably need to get .050 to .060 off to get near 8 to 1. There is a chart somebody has that shows this. On my 56 230 engine, I started with 7.6 to 1, I took .030 off the head and .010 off the block. With the .030 ovsized pistons, my machinist did some calculations on his sliderule, and figured that my engine is now about 8.1 to 1.

Here is the adapter from Tom;s catalog its 15 bucks;

[Dennis Hemingway]

This is the 2 barrel carburetor on my 48. Someone here said that it looked like one off of a Falcon. Sorry for the bad photo but the car is still in the body shop so I cannot get to it for a better shot.

Dennis:(

[Don Coatney]

To get 8 to 1 compression how much to shave off head?

Lou

[mackster]

How about for a 1953 Desoto flat six does anybody know?

[greg g]

likely thesame as the chrysler.

[Eric47Dodge]

Thanks for posting the head-milling chart. That's something that should go into the tech archive. Eric

[Frank Blackstone]

Diets are suspended for today so enjoy your meals. Just not to much that you can't fit under your ride. Oooops, too late. Health and Happiness too all. Frank

[Don Coatney]

How about for a 1953 Desoto flat six does anybody know?

Mackster;

Desoto and Crashler engines differ in 53-54 only by the length of the stroke. Crashlers used a longer stroke increasing the displacement from 251 CI to 265 CI. I have installed a 53 Desoto engine in my 48 P-15. I did not do any head work when I first assembled my engine. I have sence picked up a "Spitfire" head and plan on giving it the full treatment prior to installing it.

The only difference in a Spitfire head and the original is the raised Spitfire logo cast into the top of the head.

[Normspeed]

That's gonna look great on your motor Don. I was wondering, on your present setup did you do any grinding on the area where the intake meets the block, to smooth out airflow? I intended to do that on mine but was in too much of a hurry to get it running.

[Don Coatney]

That's gonna look great on your motor Don. I was wondering, on your present setup did you do any grinding on the area where the intake meets the block, to smooth out airflow? I intended to do that on mine but was in too much of a hurry to get it running.

Norm;

Nope. Like you I wanted to hear it run and run it did!

[mackster]

Mackster;

Desoto and Crashler engines differ in 53-54 only by the length of the stroke. Crashlers used a longer stroke increasing the displacement from 251 CI to 265 CI. I have installed a 53 Desoto engine in my 48 P-15. I did not do any head work when I first assembled my engine. I have sence picked up a "Spitfire" head and plan on giving it the full treatment prior to installing it.

The only difference in a Spitfire head and the original is the raised Spitfire logo cast into the top of the head.

That is awesome Don! I think everything I need you already Have them now I am jealous:D

[Normspeed]

Oops, sorry Lou, we wandered a bit from your post. The manifolds can be changed with the motor in, but it's sure easier with it out. The risk is possibly breaking off a stud, and doing the R&R on that with the motor in. How long have your manifolds been on the motor? Maybe they'll come off easy. On my P24 there is also a removeable fender liner piece that makes access to the area easier. Does yours have that?

If it were me, I'd watch the bay for an original type carb. I'm sure they must be out there. I'll bet it would be a smooth running modification. Factory engineering and all.

I gotta head out for turkey dinner but I do have a 1946-56 Hollander book and I'll check it for you later. I think it was a Stromberg 2 barrel.

" In 1956 Plymouth offered a 2 barrel carburetor option which gave about 8 more HP over the standard single throat. A less restricted exhaust would have probably yielded a similar amount. " Per Greg in earlier posts on split manifolds.

Now that I have run the daylights out of the engine in my 48 4 door taxi ( I have been flagged down a lot in Dublin Ga people wanting actual rides!) guess what. After sustained driving at over 55 mph of about 8 or 9 hours now ( speedo broken you know) it Idles and runs great burns a quart about every 300 at over 60- just like they did when new.

So- here is the deal I want to budget hot rod it!

I have the following:

2 Barrel intake off of something

Asche split exhaust

Unmilled head- It is unmilled isn't it Tim?

Anyone got any Ideas what carb the 56 used? or any suggestions for a replacement- Webber??

All suggestions welcome

PS Also are these mods possible in the car? I am wondering how in the hell to get to those manifold bolts.

Lou

Lou

[Guest jtw3749c]

Just a little input. I have this carb that is on the adapter that was shown earlier in this post, but the carb is a Holley. It is one of a dual carb setup.

JT

[greg g]

Based on the linkage showing it looks like it may have been mounted as the front carb in a dual set up. Can you post another pic from a little further back.

I believe the carb shown is a Holley Weber. These were used on a lot of late 70's small cars like the Ford Pinto, Mercury Capri, V6 Mustangs. etc. They were made under liscence by Holley for Ford Motors, and Carter for MOPAR small cars.Don't know the glow rate on these, but I believe they have adjustable or easily changes jets and metering rods. The v6's they were used on were in the 2.5 to 3 litre range so a single one may be a little small for the 3.7 (218) or 3.8 (230)

[Normspeed]

Hollander isn't much help on this. It lists group 21 carbs for all 6 cylinder 56 Plymouths, and those are all 1 barrel 1 1/2" bore, either Carter or Stromberg.

Maybe they would list some 2 barrels for the 57-58 flatheads but my book only goes to 56.

[greg g]

The information I have seen said that this was a single year (56) option for Plymouth, I don't think Dodge offered it as they had a V8 option already.

Didn't some of the Chrysler/DeSoto long block engines have a 2bbl? What series was it???

[Plymouthy Adams]

The L8 was a duece..being sam location and linkage set up..use one of them...

[bob westphal]

Alright, here is the question no one has asked. The milling chart shows the amount needed to mill off as .050 to achieve a 7.5 ratio on an engine with a stock 7.0 ratio. Does that mean I need to mill off .150 to get 8.5 or is the amount variable due to shape of the chamber?

[Normspeed]

Hollander does mention a 56 Power Package but they don't say what carb it used. That must be the one Greg.

The information I have seen said that this was a single year (56) option for Plymouth, I don't think Dodge offered it as they had a V8 option already.

[greg g]

Careful. In a conversation I had with George A, he said the anything more than .090 would require premium gas. I wouldn't think that a CR of 8.25 to 1 would require Premium, as most of today's cars are in that range and run on regular. That said, I would thing that .090 or less would put in the 8+ range.

The other questio is which engine, and how much space there is in the cylinder when the piston is at TDC. I noticed quite a difference between the 218 where the piston stoped with about 3/32 left and the 230 which was very nearly flush. So the same milleing on the head would yield more CR on a 230 than on a 218. Also if you have bored the cylinders and added oversized pistons, these will yield more squeeze also. So it more thna howmuch to take off the head that contributes to CR. Remember you can deck the block also.

So .020 off the block and .050 off the head, is the same as .070 off the head

as far a volume left in the combustion chamber.

[bob westphal]

In a thread I made a little while ago I said:

--------------------------------------------------------------------------------

Alright, here is the question no one has asked. The milling chart shows the amount needed to mill off as .050 to achieve a 7.5 ratio on an engine with a stock 7.0 ratio. Does that mean I need to mill off .150 to get 8.5 or is the amount variable due to shape of the chamber?

----------------------------------------------------------------------------Greg G. said:

Careful. In a conversation I had with George A, he said the anything more than .090 would require premium gas. I wouldn't think that a CR of 8.25 to 1 would require Premium, as most of today's cars are in that range and run on regular. That said, I would thing that .090 or less would put in the 8+ range.

The other questio is which engine, and how much space there is in the cylinder when the piston is at TDC. I noticed quite a difference between the 218 where the piston stoped with about 3/32 left and the 230 which was very nearly flush. So the same milleing on the head would yield more CR on a 230 than on a 218. Also if you have bored the cylinders and added oversized pistons, these will yield more squeeze also. So it more thna howmuch to take off the head that contributes to CR. Remember you can deck the block also.

So .020 off the block and .050 off the head, is the same as .070 off the head

as far a volume left in the combustion chamber.

This is good info but still doesn't answer my question. The chart shows

that on a 218 you need to take off.050 to get a .5 increase in c/r ratio. Does that mean you need to take off .100 to get 1.0 increase in c/r and so on for more c/r?

[greg g]

You might want to give GEorge A a call.

[james curl]

I had the top of the block milled to straighten any out the surface and milled the head .090. I used the stainless steel 235 cu in Chev I/6 exhaust valves which stand proud above the surface of the block, I had to releive the head over the valves to achive .060 clearance over the valve at the top of it's lift. I used solder around the diameter of each valve and rotated the cam through all of valves then measured the thinest part of the solder until I obtained .060 over every valve. If I had used the original Plymouth valves it would not have required as much work. I run regular gas and 4 degrees initial advance with out pinging.