Mopar 273-4bbl Combo

[James L Miller]

Originally Posted by Don Anderson

X2
Matt Steen @ 507-532-2436

I finally got in touch with Matt today. We had been playing phone tag for a few days. He gave me the advice of using a 318 block (he preferred an X block, not many of those around with the unbored 3.91" bores) and sleeve it down to 273 bore sizes. I think I agree as I was talking to my machinist in Tampa and he did a quickie sonic check and got wall thickness in the .160"-.180" range with standard bore blocks. It looks like Melling has some 1/8" wall sleeves that would fit in a standard bore 318 that would get them down to NHRA specs. He also seemed to prefer the 302 heads over the 920 heads. He is building a 273 stocker engine now. Matt had run the 273-4 engine as a stocker many years ago and said it was making around 330-340 HP back then.

So it looks like we either hard block the 273 blocks or sleeve a 318 down.

[Rob Ayres]

PM sent. Call me

[Greg Reimer 7376]

Back in high school, 1968-1972, two Mopars were around that were somewhat overlooked in the days of 383 and 440 Roadrunners,GTX's,Challengers, and other brand big block cars. One guy had a Dodge Dart GT, 273,4barrel and a 4 speed, and he never ceased to amaze everybody with what that little pocket rocket would do. He beat a lot of unsuspecting cars with it. Another small block fun car was the 70 Duster 340 with a 4 speed. that would give 350 Camaros and 396 Chevelles fits. It's not that I don't like Chevelles, I'm up to my eyebrows in them, but some of these other combinations are worth looking into. The Bushmakers prove that every time they show up.

[Charlie A]

Originally Posted by Rob Ayres

PM sent. Call me

You should call Rob.

[James L Miller]

I've known Rob for many years. He drove my old Joe Ralph Thompson AWB Plymouth when a mutual friend had it. I bought that car from Fred and I had posted photos of it and Rob saw it. He described it as a scary car with the straight front axle and regular gear box. I've never actually met Rob in person, but have exchanged e-mails for about 15 years. I had that article in a Hot Rod magazine when I was a kid. I guess the Mopar world is small enough where you get to know the other Mopar guys. Rob has a mid-1960s Impala that he's running with his son.

[larrylomascolo]

I had a friend who,s dad owned a 68 dodge dart,273 4spd,hub caps,14 inch bias ply green with black vinyl roof,we would take it out after his dad went to sleep,pushing it down the road,We raced a few guys with the dart and that little screamer being bone stock was impressive,good combo but like Paul said get your wallet out

[James L Miller]

Boy, everyone is telling me to get the wallet out. I think I have $40 in there or maybe a bit more. It looks like the rods and pistons might be some of the big ticket items. It looks like Melling has some 1/8" wall sleeves that would reduce a 318 stock bore (Ø3.91") down to the 273 range (Ø3.66" or so). I'm thinking using Hardblok in the wimpy 273 blocks will be a cheaper way to go. The Hardblok is about $100, sleeves are around $20-40 each, plus machining. I'll see what my machinist/engine builder wants to do, but the Hardblok looks like a less expensive way to beef up the thin cylinder walls. I wonder if the later 273 blocks had thicker cylinder walls?

[Paul Wong]

delete

[Terry Bride]

I'm slowly working on this same combination for a 66 Barracuda.

You need to keep in mind that the sleeve will need a step to retain it in the parent bore. You can't stick a 3.910" O.D. sleeve into a 3.910" bore. There will be nothing to support the sleeve. You will need a sleeve with enough oversize beyond the parent bore dia. to allow an adequate step to register against. I have not found any straight sleeve with enough wall thickness to do this. In this case, the only way to do the sleeving correctly is to get a set of flanged liners and counter bore the deck for the flange.

A custom sleeve will be an expensive investment along with some fairly substantial machining costs but in the end, you will have a block that will maintain it's bore size for many re-hones.

I will have to sonic test the 1967 273 block I have to see what it has for thickness.
In the mean time, I am saving up to purchase the pistons and maybe sleeves.