GTX motor progress... UPDATE... VROOOM!

[471_Magnum]

Hey 471 Magnum-----Could you talk a little more about some facets of your engine design. You said that you ended up with a 9.3:1 CR. You are using 452's milled down to end up with 84-85cc chamber. And the pistons had a CH of 2.067. Did you have the block deck milled at all? If so, how much was taken off and did you measure the resulting deck height? Assuming a stock deck height of 10.72, your pistons should be sitting approx. 10 thousands in the hole (assuming std stroke). What thickness head gasket are you running? Was you block bored? How much? Where did you buy your pistons and what is the part number---you said they are 12cc dished----were they special order? Are you running a standard stroke of 3.75 inches and using standard rod lengths of 6.768 inches. I am curious because I don't see how you ended up with a 9.3:1 CR. I was using the calculator at the following link:

http://www.kb-silvolite.com/calc.php?action=deck

Sorry to barrage you with so many questions but I am trying to sort out my own engine build right now. Thanks.

Heads are 452s milled to 85 cc (I checked them). Rods are 440 source H-beams (6.760"). Pistons are KB836 ($439 from Summit). Block has not been decked, but was line bored and taken 30-over. Head gaskets are Mopar Performance-sourced Fel Pro 1009s (9cc).

I didn't check the deck with a bridge since I knew these pistons would put me at about 9.35:1 at the highest. A quick check with a depth mic showed about 15 thou down.

So CR is probably somewhere between 9.2 and 9.3.

Got the clutch adjustment taken care of, fixed the exhaust pipe clearance and retorqued the oil pan bolts. Too late for a test drive though. I'll get it out tomorrow night, weather permitting.

[471_Magnum]

Got home tonight and installed the missing washer and clip.

Made another quick test loop, then stopped for a inspection. No apparent problems.

I then went for a 20 mile drive. Car runs great. I did a couple of moderate blasts, running it up to about 4500 rpm. Pulls very strong. 

I need to move the throttle cable to a different hole on the Holley, as it is a wee bit aggressive now. Hard to modulate the throttle and clutch for smooth shift. Easy fix.

Also see a slight oil drip around the oil pump. I'll retorque those bolts, and hopefully that will resolve that issue.

I think that pretty much closes the book on this motor build (knock on wood).

I'll log some more break in miles over the next couple of  weeks. Once I'm comfortable it's broken in, and I've installed a rev limiter, I'll really whale on it. 

[Charger-Bodie]

looking forward to seeing some rubber hangin from the 1/4 panels

[firefighter3931]

Excellent news Jim !  The xe274 appears to be a good match for your combo ! 



Ron