What was wrong with this cylinder? (pics)

Topic: What was wrong with this cylinder? (pics) (Read 7590 times) previous topic - next topic

What was wrong with this cylinder? (pics)

Reply #15 – March 31, 2013, 11:43:07 PM

Yeah, magnets on fish tape didn't work as it's in the cat. Unbolted the exhaust but it's too heavy to lift and pull solo. I will have to wait until tomorrow to get a helper to lower the exhaust.

So the head gaskets - run as is above?

What was wrong with this cylinder? (pics)

Reply #16 – April 01, 2013, 12:44:49 AM

Quote from: Seek;412288

Yeah, magnets on fish tape didn't work as it's in the cat. Unbolted the exhaust but it's too heavy to lift and pull solo. I will have to wait until tomorrow to get a helper to lower the exhaust.

So the head gaskets - run as is above?

Fel-Pro 1011-2? I've got a set on mine. They looked like that and sealed fine with the Edelbrock heads.

What was wrong with this cylinder? (pics)

Reply #17 – April 01, 2013, 01:39:01 AM

Quote from: thunderjet302;412298

Fel-Pro 1011-2? I've got a set on mine. They looked like that and sealed fine with the Edelbrock heads.

Yep. Expensive suckers, but will work fine NA.

What was wrong with this cylinder? (pics)

Reply #18 – April 01, 2013, 05:45:57 AM

The CR is not the factor on weather you can use lower octane.(TO A POINT)My car has a true CR of 9.2 and i run high test and 23-24 lbs of boost. Reason being the cam decides the sweep compression pressures. Basically the easiest way to explain this is simple. If you have an engine with a true 10-1 CR and the valves never close you sweep compression pressure is ZERO!! basically you select the CR by the cam and induction system you design. You dont choose a CR then select a cam or induction system. Thanks!!

Example an engine with 10-1 CR at sea level should get 147 LBS of cranking pressure. But depending on the cam this might not be true and people dont factor in the cam profile. Using compression numbers does not factor out to CR. CR is a mechanical figure and a set number. Sweep compression pressures are totally different. Just saying.

What was wrong with this cylinder? (pics)

Reply #19 – April 01, 2013, 11:21:08 AM

Quote from: TOM Renzo;412304

The CR is not the factor on weather you can use lower octane.(TO A POINT)My car has a true CR of 9.2 and i run high test and 23-24 lbs of boost. Reason being the cam decides the sweep compression pressures. Basically the easiest way to explain this is simple. If you have an engine with a true 10-1 CR and the valves never close you sweep compression pressure is ZERO!! basically you select the CR by the cam and induction system you design. You dont choose a CR then select a cam or induction system. Thanks!!

Example an engine with 10-1 CR at sea level should get 147 LBS of cranking pressure. But depending on the cam this might not be true and people dont factor in the cam profile. Using compression numbers does not factor out to CR. CR is a mechanical figure and a set number. Sweep compression pressures are totally different. Just saying.

The cam isn't changing. Moving up .5-.6 on the static compression ratio with aluminum heads should run on 87 octane as the irons did at the lower compression. All else being equal, the change in static compression will pretty much increase the dynamic compression linearly (about as close to linear as one can get).

So explain how the final compression isn't going up 6-7% is everything else stays equal?

What was wrong with this cylinder? (pics)

Reply #20 – April 01, 2013, 01:18:43 PM

IT WILL i know that!!! But i just wanted to point out the difference between sweep and actual. Some people dont realize the difference., just saying!!

What was wrong with this cylinder? (pics)

Reply #21 – April 01, 2013, 05:18:46 PM

Yeah, I agree. I do seem to see people bringing it up all over the place the last couple years, even in places where it doesn't really belong. It's better to have the information than not though.

As for this thing, I'm not sure I'll get it fired off tonight since I have numerous things to change and swap out before bolting the motor back together, but I'll get there. I plan on changing the oil immediately with the old filter left in there (using cheap oil). Then I'll change it again with my good oil after a few miles just because I hate the idea of ANY coolant mixed in there. It will smoke a bit though, as I've slathered oil on everything that isn't a gasket surface. Also haven't fitment-checked my valve covers. I want new ones, but I may have to grind the casting inside my stock Mustang covers a bit to get them to work for now.

I'm just hoping for a smooth idle - there's no reason the Mustang cam shouldn't be able to idle smooth without any detectable stumble anywhere.

Also, the orange colored exhaust valve wiped right off with a dry paper towel. It basically cleaned up while the other ones have a hard white film that would need chemicals. The orange valve was like a fine surface rust. It confuses me as it seems it'd blow right off in combustion, but the car was driven just 2 days before it was pulled apart.

What was wrong with this cylinder? (pics)

Reply #22 – April 01, 2013, 05:41:56 PM

Quote from: Seek;412301

Yep. Expensive suckers, but will work fine NA.

I think I spent less than $40 for the pair. They work great NA but I've heard they have issues with boost. The 9333PT-1s are better in boosted applications.

Thinking back to when I pulled the GT40Ps off of my car I believe it had one funky looking exhaust valve as well. It was on cylinder #2 and it was a differnt color than the rest of the exhaust valves. I have no idea what it was as the engine ran fine and had good compression.

What cam were you running before? The Comp Cam I have idles pretty much as smooth as a stock HO cam and pulls harder up top. I've never had a hesitation issue with it.

What was wrong with this cylinder? (pics)

Reply #23 – April 02, 2013, 02:34:57 AM

I've only used this '89 HO cam since moving away from the stock motor. I was tempted by some cams a month or so ago, so I had NO idea what would fit since I had the heads milled quite a bit, and I didn't know where my pistons sat in the bore. I'd probably want to move up to a 408 rather than swap the cam. Also I found that Chuck's motor mounts appear to make the motor sit HIGHER than the stock hydraulic mounts, so that will make me need to re-think fitting a larger motor under the stock hood.

Anyway, I'm not sure why my intake valve's sweep is a bit off center versus the exhaust. Previously it was easy to shim in the difference with pedestals. Now I don't know with stud mounts? The below was with 6.700" pushrods and solid lifters. Very narrow sweep, but the intake valve is a bit off center.

The sweep is a pretty low 0.045".

What was wrong with this cylinder? (pics)

Reply #24 – April 02, 2013, 02:43:36 PM

I should also add, I forgot to use my reducer bushings that I purchased. Although these heads were supposedly drilled out to 1/2" and the 1/2" studs were included in the shipment, I pulled one nut and CANNOT get the 1/2 to 7/16 bushings to fit. I then tried the 1/2" studs and they also aren't even close to fitting in the hole. The hole appears larger than the ones in my GT40P heads, but also a lot smaller than a 1/2" bolt would take. I can't get my caliper to get me a good measurement since the jaw isn't long enough, but the holes in these heads appear to be closer to 15/32. They are exactly between 7/16 and 1/2".

What should I do? I have the dowel pins in for the centering and everything originally torqued well. If I pull the heads to have them opened up to the full 1/2" so I can use the reducers, I will have to re-purchase $85 in gaskets that I'd need to special order. Can someone provide real insight on the need for the reducer bushings? Looking on Google, it seems many experienced builders claim the reducers aren't needed, but they can't hurt - the dowel pins locate the head and the bolts just clamp the head down. Others that appear to know less on the subject say that you need the reducers, period.

My machine shop was more worried about the arp washers. He told me I should be fine without the reducers (he originally recommended I get them) with my information above, but recommends adding an additional grade 8 washer to each stud to make sure that the nut doesn't cause the washer to bowl into the hole.

Anyone with actual experience with engine building have any suggestions? Tom?

On another note, the machine shop also would like to see if I can get the wear pattern above closer to the center, even being only 0.045" sweep right now, and run two different pushrod lengths if needed. Many seem to think the above picture should be good to run as is. Since the TW heads have more of an angle on the intake valve (IIRC), the slight exhaust bias might help counter the side loading that the angle would produce?

What was wrong with this cylinder? (pics)

Reply #25 – April 02, 2013, 03:02:54 PM

If I remember correctly the Trick Flow heads have a smaller opening than ½” for the head bolt holes. The holes are stepped with the top being small and the lower part being larger. The idea is that the reducer washers won’t be necessary on 289/302 blocks. If you’re running a 351W all you have to do is bore the hole the extra ¼ way through to get the size to ½”. So basically if you’re running the heads on a 289/302 you don’t need the reducer bushings.

The Edelbrock heads I used had ½” holes so I used ARP bolts and reducer bushings. They fit right in the bolt holes no problem.

As for the pushrod issue it looks like you may need slightly shorter (6.650) pushrods to center the mark on the valve tip.

What was wrong with this cylinder? (pics)

Reply #26 – April 02, 2013, 03:27:20 PM

I assume you mean shorter pushrod, not longer.

I'm still not sure if any changes are needed? No matter the car, it seems we want the narrowest contact path and that the position shouldn't really matter. Narrow meaning that the rocker is pretty much perpendicular with the valve and pressing down on it evenly. To get a perfectly narrow contact path in the center of the valve, you need perfect pushrod length and rocker arms.

I will get some more checking done tonight, but there is a good chance that a shorter pushrod will make the contact path a bit wider.

What was wrong with this cylinder? (pics)

Reply #27 – April 02, 2013, 03:42:34 PM

I liked this example found of contact area versus contact point:

Lay a pencil on your desk, eraser end facing you. Push on it with the tip of another pencil, in the center of the eraser, exactly in alignment with the pencil. Which way does the first pencil move?

Now push on the eraser out near the edge, but still, in exact alignment with the length of the pencil. Which way does the pencil move?

How much did the pencil's motion change?

Now push on the eraser in the exact center but in some direction other than exactly in alignment with the pencil; say, 20° off its axis. Which way did the pencil move?

Conclusion: which change made more difference: moving the contact point, or moving the relative angle of the force?

What was wrong with this cylinder? (pics)

Reply #28 – April 02, 2013, 03:49:42 PM

Quote from: Seek;412427

I assume you mean shorter pushrod, not longer.

I'm still not sure if any changes are needed? No matter the car, it seems we want the narrowest contact path and that the position shouldn't really matter. Narrow meaning that the rocker is pretty much perpendicular with the valve and pressing down on it evenly. To get a perfectly narrow contact path in the center of the valve, you need perfect pushrod length and rocker arms.

I will get some more checking done tonight, but there is a good chance that a shorter pushrod will make the contact path a bit wider.

Yes I meant shorter. I just had a brain cramp. I fixed my post. :hick:

You could try a shorter pushrod but I'm not sure how much of a difference it would make.

What was wrong with this cylinder? (pics)

Reply #29 – April 02, 2013, 05:47:35 PM

Another thought - the checks above were with a solid lifter. If I were to use a 0.030" (3/8 turn) preload on hydraulic lifters, it would essentially move the mark that much toward the intake side, correct, and help the exhaust be more in alignment. This would provide a good average between intake and exhaust.