Flathead Crate Motor

[pflaming]

Go back up a couple of posts to Don Coatney's dual carb set up. The back carb has the link I am referring to. He has the link on the back carb but not on the other. Interesting and perplexing.

[bearheart]

As a newbee to flattie Mopars I am really impressed with how you guys can make them so pretty. Thanks for sharing

[JBNeal]

I've been contemplating the pcv system for the flathead and recall something out of place on the 230 that's in my 1 ton. When I found it, it had a crankcase filter (looks like p/n 627488) and no draft pipe, although it looked like it had some sort of tube on it at some point. This filter is standard on big trucks for that year, as well as all export trucks. The guts of the draft pipe crankcase filter are very similar to the guts of the oil fill tube crankcase filter. I have replaced the draft pipe crankcase filter with a donor draft pipe just to match it to the setup on the 218 I have in my '48 1/2 ton.

I recall that Chrysler's pcv system on the 318, 360, etc. pulled vacuum from both banks of the V8. One bank had the pcv valve that used a vacuum port from the air cleaner body. The other bank had a crankcase filter that used a vacuum port form the throttle body.

Knowing this, I'm wondering if the flathead needs a filter between the pcv valve and the crankcase. I'm thinkin' that sludge might build up in the pcv valve & the lines and restrict vacuum.

Anyhow, the next time I'm at the parts store I'm gonna try to get some better ideas on what's available that could work. I'll post pics & p/n's with any 'breakthroughs'.

[41/53dodges]

just exactly how much does a duel carb setup improve performance anyways?

[48Dodger]

In simple terms "performance" means how strong your Torque number is. HP is a number used to determin Torque. You can think of HP as the engine's ability to replenish the cylinders with gas. As the RPM's rise, the carb falls behind for the demand of gas. With the second carb you get extra help, or, better perfomance. The gearing is the Torque, but is really the finally answer of all the components front to back. If you think of a bulldozer, completely geared to knock a building over, can do it with 80-120 hp. Why, because the relationship of the rods to the crank are providing the leverage and low RPM's. In otherwords, if you compared a 450Hp 340 engine, to a 450Hp 440 engine in the same car on the 1/4 mile.....the 440 would win due to its torque advantage (leverage from the rod/crank relationship). Gas mileage has become a measurement of performance, but in most "performance circles" it's not.

48D

[41/53dodges]

i know the mechanics of it all, i just wondered if anybody had any numbers as far as improvements on a dyno or something.

[greg g]

I ran my dual carbed 230 on a chassis dyno last year. I can't say know what the numbers mean as the chart puts in a number representing HP needed to push a vehicle down the road at 50MPH supposed to represent the aero and frictional losses. Of course the book doesn't have a number for a 46 Plymouth so we left it out. But pickups and suv with not much aero were in the 35 to 55 area. Also I did not run a full RPM pull, I limited it to 70 mph on the rollers which if I rember right was 3340 RPMS. Peak factory HP was supposed to be at 3600, and was flywheel hp. My engine is a 56 which was rated 125 stock at the flywheel.

The results at 70 were 77HP at the rear wheels, so if you use the + 35 to 55 for areo, that would give me 105 on the low end and 125 on the high end. Again this is rear wheels not flywheel, Conventional widsom would give you a 25% frictional loss between the fly and the wheels so stock should have been 90 or so. So I think that says I picked up some HP along the way. Other mods were .050 milling of the head / deck, and a .030 overbore. Single exhaust 2 inch ID and turbo flow muffler.

Seat of the pants, more grunt all the way through the gears, noticable increase in 40 to 70 mph acceleration in top gear. And better gas milage by 4 MPG. I also put taller tires on which would normally give slower acceleration, and less throttle response in third.

Probably the biggest gain was through the milling which increased cr from 7 to about 8.5, and allowed some more timing advance, a run about 6 BTC initial.

Hope that answers your question. By the way in 56 there was a 2bbl optional intake, which accordnig to the charts raised hp from 125 to 131. I don;t think thee were any cam or CR changes between the engines at the time.

[Buford Solomon]

Forgive my ignorance, but what the heck is a "crate motor?" I've seen this term used elsewhere, but nothing in the context here or elsewhere really provided a definition.

Thanx

BS

[Young Ed]

A new motor in a packing crate

[greg g]

I think in this case he was refering to the crate like stand he made to work on / store his engine. Check out the pics in his first post. In modern terms it usually refers to the plug and play GM and Ford engines you can pick up down at the local drug store.

[greg g]

I think in this case he was refering to the crate like stand he made to work on / store his engine. Check out the pics in his first post. In modern terms it usually referst to the plug and play GM and Ford engines you can pick up down at the local drug store.

[Young Ed]

There are mopar crate engines too. 340s 360s 426 hemis 528 hemis v10 viper engines

[John-T-53]

Haha, from the point the pics were taken, this flattie was a plug-n-play unit; it just dropped in and went. At the time I think I was trying to mentally get past the months of rebuilding and detailing, including building the crate, and move forward as if the UPS guy had just dropped it off.

2300 miles on it so far...

[JBNeal]

Forgive my ignorance, but what the heck is a "crate motor?" I've seen this term used elsewhere, but nothing in the context here or elsewhere really provided a definition.

Thanx

BS

I reckon I found a Crate Motor...any takers?

Edited March 24, 2010 by JBNeal
added picture

[Tony WestOZ]

I reckon I found a

Crate Motor...any takers?

That engine has been around for awhile now and he still has not sold it.

I don`t care what he says, an engine this old should be opened up and inspected.

I have a NOS engine which had been in supposed dry storage and I am luck I open her up. Fine rust on all surfaces, specially around the rear crankshaft seal. Managed to clean it all up but all the seals have had to be replaced as well as gaskets.

Just hope mine looks as good as John`s when its all back together.

Edited February 16, 2010 by Tony WestOZ

[MBF]

That town is about 100 miles from here-I know the area pretty well. Take a 0 off the price and you'd probably own it. But you'd still have to open it up. I bought a used slant 6 for my pickup last fall that was adverstised as running great-no noises-good oil pressure. Opened it up to find it full of sludge w more cylinder wear than my own engine. Only paid a couple of hundred bucks for it but it s still sitting on the garage floor-rebuilt my own. A buddy of mine bought an engine that was supposedly rebuilt from a reputable garage. We put it in his truck and started it and it smoked like a chimney and shortly after threw a rod. The seller forgot to mention that despite all the machine work that was done to it-that it was underwater in a basement for a short period of time. Live and learn I guess.

[Young Ed]

Well sometimes they are worth looking into. Dads 63 valiant had a tired /6 in it that was way more modern then the car. Buddy of mine had a lead on a 6 out of an a100 that was fairly recently rebuilt and for sale cheap. They told us $50. When we got there they took even less because they decided to keep the carb off it. Now due to some other circumstances we ended up pulling the head and having a look and that engine looked brand new inside. Runs like a champ! Other circumstance was no vacuum and poor idle. Checked and rechecked everything including pulling the head to look at the valves. Finally after that we got ahold of my buddy he asked the previous owner and found out it had a hi-po cam in it.