289 head swap

Last September my 302 was running poorly due to bad valve seals.
During the winter, I decided to breathe new life into the heads.
During teardown I noticed the heads were 1977 cast smogger heads, they had to go. (boat anchors)
I had a pair of 289 heads (1965), cleaned, pocket ported, K-coded, 1.94 chevy intake, 1.60 chevy exhaust,
Z28 beehive springs, hardened pushrods, shaved .010 to make upwards of 400 ponies.

 

Spring pads don't look like true k code heads but they'll surely be a world better than those bigger chamber smog heads. With 4 valve reliefs and pistons down below deck like that, might be getting close to making 10:1 compression. And unless it's a much bigger and peakier cam close to or over 240 degrees @.050?.. I'd guess maybe around 310-320 horse with that smaller more restictive performer manifold. An open 1" tall spacer will help it make more power and rpm a little better.

 

Here is a short video of it's first run since the swap.

 

The picture of the single head was when I was doing the valvetrain geometry for the rockers.
First, the heads went back into the machine shop I was working to have spring pads recessed.
With 6.800 pushrods, the cam was 292 degrees @50 with 498 lift.
What manifold do you recommend? I already have a 1 inch spacer.

 

I would suggest getting rid of the plastic gas filter. Had one rupture/broke off at the nipple, sprayed gas all over the engine until the car stalled. I was lucky to be only about 1/2 mile from home, but still had to get on the hook,. I was very lucky didn't set car on fire.

 

292*@.050???

That sure sounds fishy.

 

You definitely need better heads. You did upgrade but even a gt40 head would be an upgrade from what you have there and get you closer to your goal.

 

290/290@50 with .444 lift (before head swap)

 

290.0 has to be your advertised duration not duration @ .050 tappet lift.

Best dual plane intake would be a Weiand Stealth or the Edelbrock Performer RPM. Personally, I like the Stealth.

 

Yep.. most likely 292 @.006 lifter rise. Not nearly as aggressive a lobe design as say a 270 @.006 roller cam but still a decent sized stick for these little motors.

From all I've seen and read.. the Weiend stealth has better casting and machining quality than Edelbrock rpm but performance is nearly identical either way you go. Probably have to forego the spacer with either choice though as those manifolds are already much taller than the regular performer manifold and barely fit as is.

Wasn't trying to diss your combo.. just a cynical realist by nature, is all. Good sorted 250 horses getting to the ground in one of these lighter cars should feel like 300 or more in many other heavier ones. Put some rear gear in it and have fun!

 

Hard to believe since the Edelbrock is made in USA and the Weiand made in China. Not saying you're wrong though. Just the first I've heard of it.

 

Yeah.. not everything is as it would seem Larry. I've ground, ported, and welded on both. Sent several edelbrock parts back due to casting blems and poor machining. Casting porosity can rear its ugly head too but by the time you get that far into it the return policy becomes moot and needs puttied or welded whenever accessible. Edelbrock went downhill when it became a big marketing venture greedfest for his kids. Not many alternatives though unless you want to take your chances with china made copies.

 

What I have learned about Chinese made parts is the company having the product made dictates the quality. We get cheap garbage because they ask for it. Could be Weiand is holding up their end and specifying a superior product. We sell a boat load of import cam lock in aluminum and stainless and short of weight they are on par with the domestics. This is because PT Coupling has them cast with the very same alloys used in their Enid, OK facility. Even domestic product can be garbage when corners are cut in the name of profitability.

 

I have a stealth on the Comet with a 1/2 inch spacer. There may be enough room for a 1 inch. I like the older Stealth castings, as they had rear water crossovers and a couple of tapped openings. It allows you to hook your heater hose and/or temp sensor in the back. Just my preference. If you go Edelbrock, a RPM or old F4B design, don't waste resources on a Performer.

 

Yep, exactly. My jab was mainly aimed at the companies who outright steal and copy intellectual property conceived and sold by others. Procomp, now called Speedmaster, is notorious for that type of theft.

The biggest thing most people fail to realize is that in order to lawfully print the American flag on a product only requires that a measly 30% of the entire product needs to be manufactured.. or simply just assembled here. Whole thing could be made elsewhere and then shipped here in pieces and/or with only minor additional machining required. Toss it in the foreign made box and viola.. American made. Stockholders and upper mgmt makes tons of money and they all get big bonuses. So as you say, it's not so much where it comes from.. but the amount of greedy corporate hands that have touched it on its way into the box.

End rant. lol