Cam timing off? Who rebuilt it?

 

Xj, what makes you think the valves are hitting the pistons ? has the engine been disassembled again ? what pistons were used ? what timing set was used ? As RedNeck asked, are we sure cam timing was correct ? That cam is not large by any description, which would make me think either the wrong pistons were chosen, the wrong crank was used, or the timing chain is a tooth off. LSG

 

Hmm, pretty sure some one more knowledgeable then me will speak up. But I thought the 302 needed the 2M crank. So when you say the pistons are stock, is that stock 302 pistons or stock 289 pistons? Since it sounds like you are using 289 Crank and 289 rods in a 302 block and not sure on pistons?

 

Well to be honest, this was the brief discussion I had with the shop today and haven't had a chance to follow up. This is what they told me and I know I'm missing some of the details from the conversation (I should've taken notes). It all comes as one top-end kit and I'm assuming my pistons are stock (didn't see any codes on them as the motor was only taken to a short block). The kit is designed for a 289-302 and I have a pretty much stock 289 setup. My estimate is that there was an issue with the original block and all the contents were moved to this newer, later block.

 

Check it with a borescope. How many miles on it since the engine was put together. Don't think it would last too long if they are. If they really are hitting, rocker arm ratio off?

 

Check the push rod length if they were replaced, as there were a few different options used over the years.

 

What heads are you using and what are the valve sizes?

 

A 74 block shoud have about 0.022 more deck height than earlier ones. I think this lasted from 74-77. So if valves are hitting some thing is way wrong.

 

SO many variables, deck height, head thickness, head gasket thickness, piston type, pushrod length, valve timing, valves themselves. SOmeone needs to go back to basic principles. These motors and cars are like archeological digs. Its hard to know what someone else did in the past. Heads get milled to raise Compression Ratio, deck blocks, decide to use chevy valves to increase what ever and I even met a machinest that offset grinds a stock crank when he rebuilds it to get a tiny stroke advantage - people do lots of interesting things and the wrong combination... Personally, if there is an impact issue, head removal and clay is the only way I would feel comfortable solvign the problem.

 

Exactly.

 

Were the push rods or rockets substituted or replaced?

I typed that last night but it just posted. Oh well.

 

Xj, several questions. What happened to your iron 65 289 heads ? Those are sought after by folks looking to build higher compression small blocks, guys like me. If the shop didn't give them them back to you, they owe you some serious money. Ford hasn't made that casting for more than 50 years, and it would be a serious mistake to let them disappear. Do you know if you came in with a D4 block ?

Heres an idea. Maybe your valves aren't hitting the pistons at all. Maybe you have a bad combination of parts. If your valves were hitting the pistons, it would NOT run fine. But suppose your guys lost or damaged your crank, or unintentionally mixed it up with a 302 crank ? If one used a 2M 302 crank, with a 1.500 throw, and the common rebuilder shorty flattops at 1.585 tall, and your C3 289 rods @ 5.155 long, you'd have an assembly height of 8.240, and your D4 block is 8.224 tall. You still have the gaskets @ 0.035 ish, but as the pistons rock aT TDC, they can lightly tap against the heads. Seen it happen to folks who weren't aware of the finer points of the baby Windsors. I'd be pulling the heads and checking for witness marks. LSG

 

I'll remember to grab those heads, thanks for the info on that. The entire short block remained untouched during the rebuild (the motor was actually really clean and ran really well), so the only thing really modified has been the top end and cam. I've been visiting the shop about once a week to see how things are going, too.

I don't know if the block has been decked at all, but the heads are brand new Edelbrock E-street #5023, the pushrods are 6.805" long, the pistons are stock, head gaskets are 0.045" thick, and the valves are 1.900" intake and 1.600" exhaust.

We suspect it's an issue with the cam, in that the wrong cam was sent in the kit but we won't know until pulling it back out and looking at numbers. We'll contact Edelbrock after Christmas to see what other things could be going on before pulling it.

As a note, I looked over my old cam and was wondering if you guys could help identify it. The only things I see on it are CWC 1206, on the end it has 910914 stamped, D3 C3 between the distributor gearing and lobe, and a D1 and 4 on the other end. I measured the lobes to have .245 and .260 of lift, too. Thanks again for all the help.

 

The CWC stands for Campbell, Wyant & Cannon (a company that casts camshafts and is a subsidiary of the Textron Company). Hard to say who ground it, but with lift numbers like that it was probably a generic replacement cam for the '74 motor.

 

Xj, if your shortblock is untouched, your engine is not rebuilt. But keep in mind that valve & piston collisions usually mean an engine that runs badly, if at all. You'll want to look for witness marks. And you'll want to pick up your original 65 289 heads, put them in a box, and ship them to me ! LSG

 

Since I’m impatient and I can’t let things wait until after the holidays, I was looking pics of the assembly and wanted to throw things by the more knowledgeable here. The first pic shows the top of the more minus the intake manifold. Looking closely, you see the #1 exhaust valve is open, the #3 intake valve slightly open, and the #7 intake valve full open. Now, I could be way off on this but wouldn’t that mean it’s a 351 cam with that firing order? Also, the second pic shows the cam being installed and I know it’s hard to tell just looking at pics but it looks pretty big in terms of lobes. Maybe I’m grasping at straws here but just thinking of possibilities. Thanks for the help and Happy Holidays.

 

The change in the firing order didn't cause your problem. The pistons are still going up and down in the same sequence they went up and down previously but now instead of specific pistons going up on the compression stroke they are going up on the exhaust stroke and vice versa.

 

But if the timing is off then wouldn’t that be an issue in terms of cam and crank? Maybe I’m just grasping at straws.

 

I can't tell open from closed in your pic ,but i had Jegs house brand of the 448/472 cam with the 351W firing order in my old 289 so that alone isn't an issue it would of course need to be wired as such

 

Any SBF can run either the 289-302 or the 351w -5.0 HO cam. The only difference is were the plug wires go on the distributer. My backup 289 has a cam with a 351 firing order.

 

Thanks for the info. Does that cam look like it might be 351 though? If it’s the wrong cam, it may be much higher lift than what’s supposed to be in there.

 

The size of the engine has no bearing on the can lift numbers.

 

Right, but if it’s a 351 cam, that’s not what was supposed to be sent and it could have higher lift numbers as we which could be causing the interference. It was supposed to come with a 302 cam.

 

In your op you posted the lift numbers. If you know the lift numbers then no, it being of 351w firing order is of no consequence to this issue.

 

The shop aparently did not degree the cam or they would know if it was the wrong one.
Not the best of signs imho.
Given that it would seem to either be the wrong cam or the valve relief fly cuts in the piston may not accommodate your new heads valves. But 1.90/1.60 are standard sizes?
Do you know what valve sizes you were running in your old heads?

 

Did I miss something? It would seem that, at this point instead of speculating, it would be logical to yank a cylinder head and throw some clay on top of a piston......

 

Basically the firing orders are interchangeable. On a carburatored car it's just a matter of changing plug wires. On a EFI, spark plug and injector wiring. The EFI would still run even if you didn't swap injector wiring, it just wouldn't run as smooth at some points. The 351W/5.0 wiring goes back to 1932 on Ford's first V8, the Flathead. The Flathead center cylinders on each side shared a common exhaust port. This way adjacent cylinders sharing the same exhaust port don't fire one after another giving the port a chance to breath. This firing order also makes the engine run smoother from a vibration standpoint.

On the crank and cam aligning dots it doesn't matter if they're both at 6 or 12 or 6&12 or 12or6 since it's a 2:1 ratio and all line up at 12&6.

Unless the dots were not strate up at 6 or 12 but at some other spot you shouldn't have issues. If in fact the valves are hitting the pistons, you may have one at 6 and one at 10 or some other odd ball location. You can use a straight edge to check the dots.

Oh Merry Christmas!

 

All, thanks for the help. Here's an update to the situation. To be safe, we decided to pull one of the heads and clay a piston to make sure 100 percent what was going on and sure enough, there is contact on the edge of the intake valves. You can't really see any contact on the pistons but I've attached a pic of them anyways. Needless to say, I'm not sure where to go from here. I don't know anything about the pistons but they have 040 stamped on them so the block has been bored over (most likely when it was rebuilt years ago, before I owned it). It's frustrating that something that is supposed to just bolt to the motor and go, doesn't. On a personal note, I tried to be responsible and not get carried away and go over the top in order to keep the costs down. In the end, I should've just gone with a crate motor. Regardless, here I am.

So here are the options that I can see so far:
1. Crate motor. Pros: new, good motor that I know works and has power. Cons: expensive and now I have to try and sell my old motor and parts.
2. New pistons. Pros: new pistons means I can go with a stroker, more power. Cons: expensive, time consuming and now I'm piecing together a motor that could lead to more problems.
3. Put the stock heads back on. Pros: cheapest, quickest, easiest. Cons: I'm left with an intake that's not that much of an upgrade from before, and a warmer cam so all this money was spent for minimal power gains.

The original goal of this project was to clean up the engine bay and replace the gaskets of the motor so it wouldn't leak anymore. I figured since the motor would be out already, why not add some power (hence the kit). Unfortunately, nothing is ever that easy. Thanks again for the help.