The Dodge Challenger Message Board

Hi guys, i have a friend with a 1971 Vert,which have a 340 engine
which is done and tired.-
My friend is on a budget but i recommended him go thru a mild performance list of parts...what parts do you recommend ?

Any advice will be well appreciated !

- Pistons and Rings set (.30 over)
- Complete Bearings
- Oil Pump
- Fuel Pump
- Lifters or tappets (This have tower from what i see_)
- Rocker arms
- Valves

- A matched set of :
Edelbrock Carb + Intake manifold+Camshaft RPM Performer
- Valve springs to match the cam specs
- Gaskets

Thanks any info will be really appreciated !!!!

I'm helping a friend do the same thing.
Start with the required machine work on the block, and chose the pistons accordingly. Beware of the new piston choice.
340 normally had high pistons and open chamber heads (the pistons protrude above deck and into the head).
The replacement KB piston is made like that too.
It's possible to get Diamond flat-top pistons (from Hughes). And thus use closed chamber heads to keep compression around 10 (it may be cheaper to buy new heads than to rebuild the old ones, so look at the piston type/head type/block work at the same time).

My friend's block needs a bit of work (the bores look fine, but the decks are of different heights (close to one mil shorter on one side!)

I would also suggest new heads, rebuilt iron heads can be had for $500 a pair (http://www.aeroheadracing.com/id6.html )

Hughes engines has a couple nice cams for the small block, my friend will probably take the HEH1928AL camshaft and 4600-P
heads (I modelled the engine and got a simulation result of 335 HP at 5500 RPM with manifolds and this cam, with 9.5 C/R).

The 20-212-2 cam from Comp is similar (that is the stock replacement from Comp for the 340ci). And the HEH2328AL cam is good for a trifle bit more power (and the 20-223-3 from Comp is similar to that one).

The biggest improvements on the simulation though, were the prepped heads and putting on (small-tube) headers (went from roughly 340HP@5500 to 400HP@6000 and from 375 lb.ft to 413).

The deck surface on a small block can be way out.

A friend of mine had his 340 re-bored and the bore cutter went right through the side of the cylinder. This was because they assumed the deck was level and it was not. So the bore cutter went down at an angle.

Always get the deck leveled with the crank centerline first.

airfuelEddie wrote:The 'Man' for true .904 MoPar cams is Scott Brown,(1-616-499-6223), he's a pleasant and very knowledgeable man to deal with. Unlike the above supplier

I never said Hughes was nice. But being the [person] he is, if he had shitty products too, we sure would never speak of him around here.

I have a camshaft from Scott Brown on my white Challenger, but I would not recommend a Scott Brown cam for a budget rebuild, or a near-stock rebuild, because Scott's shafts are rather at the other end of the spectrum (all-out racing, wild overlaps, agressive ramp rate).
Besides, in the last 2 years, he's been extremely difficult to reach (since he closed down Straightline Performance to join Copetition Components, and I heard he left the latter a while back on moparts)

Hi we are back on track !





My friend finally agreed to do the rebuild so we pulled the engine off the car ...

Im currently looking for rebuild kits but the bore sizes are strange to me
im a GM guy so im not sure what's what we need,the machinist told us that the engine is no good for .30 over ..so we might do .60

Im searching here :
http://www.summitracing.com/search/Year ... rd=rebuild

Thanks !

Anything over 40 thou is possible but not ideal as these blocks were cast as light as possible to save weight and material costs so the cylinder walls can be pretty thin (varies from block to block). Piston ring seal and block strength can be poor if the cylinders are too thin. Probably not an issue if the car is not raced though.

[quote="dave-r"]

A friend of mine had his 340 re-bored and the bore cutter went right through the side of the cylinder. quote]

Ouch........nightmare stuff.

I have had 3 blocks .060 over with no problems. Not race engines though.

Thanks , which kit do you recommend ?
and btw why does it vary from block to block
how can i know the difference ?
The other option we have is to go back to standard by sleeving it...
what you think ?
Thanks !

All castings vary from foundry to foundry, batch to batch and mould to mould. Some are just better than others for various reasons and some are cast with thicker cylinder walls than others. They can be checked but for us normal guys it is usually not needed.

Chrysler say go no bigger than 40 thou over. But plenty of people have gone 60 thou over with no problems. If it was a serious race engine though you might be better off finding a better block. Otherwise just go for it.

Thanks, we'll do it
It won't be a race engine at all