Breakin on newly rebuilt 302 FT cam engine starts and dies after 2-3 minutes

[Rockstar Bronco]

Thanks Bowsher. Mine is a 74 block with FloTek heads. Only removed .030 shim. Spring seat is intact. Pretty sure I'm on track with the valve train. Just ordered hardened pushrods.

I acknowledge that I started this when I misnomered my rockers as "non-adjustable" in my OP, but let's clear up the "adjustable vs non-adjustable" rocker arm confusion once and for all, b/c I'm getting varying claims from all directions about it. My understanding (correct me if I'm wrong) is that if you have threaded rocker studs with a lock nut and ball washer on top of the rocker arm (my oem Ford), that is an adjustable setup. You have three contact points: the rocker stud (fulcrum), the pushrod, and the valve stem. You tighten the nut to zero lash + 1/2 - 3/4 turn and you're done. That's how I've always done it (maybe 6-8 times over 40 years of building cars as a hobbyist- never had a problem). Conversely, what I understand to be a non-adjustable rocker is where there's a pin that goes through the rocker the other way (parallel to the head), where you have no room at all for adjustment.

Hoping a qualified member will set this straight. TIA!

 

[73azbronco]

I'm just saying, lash and pushrod length aside, if it starts and hits 2000 rpm for seconds, then stalls, its most likely fuel or spark. Valve lash would result in rough running or no start at all, or the dreaded start rev die with no delay.

 

[73azbronco]

Thanks Bowsher. Mine is a 74 block with FloTek heads. Only removed .030 shim. Spring seat is intact. Pretty sure I'm on track with the valve train. Just ordered hardened pushrods.

I acknowledge that I started this when I misnomered my rockers as "non-adjustable" in my OP, but let's clear up the "adjustable vs non-adjustable" rocker arm confusion once and for all, b/c I'm getting varying claims from all directions about it. My understanding (correct me if I'm wrong) is that if you have threaded rocker studs with a lock nut and ball washer on top of the rocker arm (my oem Ford), that is an adjustable setup. You have three contact points: the rocker stud (fulcrum), the pushrod, and the valve stem. You tighten the nut to zero lash + 1/2 - 3/4 turn and you're done. That's how I've always done it (maybe 6-8 times over 40 years of building cars as a hobbyist- never had a problem). Conversely, what I understand to be a non-adjustable rocker is where there's a pin that goes through the rocker the other way (parallel to the head), where you have no room at all for adjustment.

Hoping a qualified member will set this straight. TIA!

Picture worth 10,,000 posts

 

[Rockstar Bronco]

You're right, AZ. I have painting to do early this week, but plan on having the motor back together by the end of the week. Will follow up then ...with pics and update. Maybe post a video link?

 

[Rockstar Bronco]

Well, I finished all my painting (which went well), followed by 2 days of reassembling this motor, and now 2 days of hell trying to keep it running... Installed the new hardened pushrods, set the lash, replaced the battery and coil. Discovered bad ground on choke ...moved that to good ground. Started right up and ran for about 3 minutes, then died again. I'm using a cheap HF timing light (Cen-Tech 40963) with advance dial on it. This is new to me and didn't notice that it was advancing the 1st time I used it, so timing was advanced +20 over what I wanted in the beginning b/c the light was set at 20 degrees adv. Here's what has me vexxed about it. My whole shop smelled like a chemical factory fire, as my header paint was being completely torched off (smells worse than plastic burning and still stinks badly the next day). Strangely, it wasn't burning up close to the heads, but down almost to the collectors. I know what you're thinking, BUT timing's running about 28 degrees +/- at 2200 rpms, which is where I need rpm to stay while breaking in this new flat tappet cammed motor. I do have vacuum advance connected. I've tried it both ways, on and off, but since I'm timing it at 2200 rpms, I don't think it matters. Or does it? Sprayed 1/2 can of carb cleaner through it, just to see what that might do. That didn't kill it, but it petered out about 45 seconds later. I'm setting rpms by turning in the idle screw and then varying it (on the few times it's stayed running for more than 2 minutes). Initially, it starts up fine and seems to run well in the beginning, but gradually, it starts to sound like a tractor, like its binding up or the timing is all wrong, and becomes more difficult to start. I was methodical about installing cam and timing set but it sounds like timing is off. I was also very careful to ensure plenty of end ring gap when I installed the new Hypereutectic pistons. At a complete loss with the header paint going up in flames. That's a sign that fuel is burning late, in the headers. How is that happening? Hopefully this dings a bell in somebody's head. Just trying to get the motor broke in and this is NOT the time to be dealing with all this starting and stopping 15 times. I'm at the end of my rope here. Exasperated beyond words... mainly b/c I've been working 16 hr days for 8 months, and spent ALL my money (and credit cards) to finish this project... now winter is breathing down my neck and suddenly it's one problem after another.

PS: Tried to upload pics, but this site only allows you to post a link to a url? Sorry, I don't live in "the cloud".

 

[bmc69]

Thanks Bowsher. Mine is a 74 block with FloTek heads. Only removed .030 shim. Spring seat is intact. Pretty sure I'm on track with the valve train. Just ordered hardened pushrods.

I acknowledge that I started this when I misnomered my rockers as "non-adjustable" in my OP, but let's clear up the "adjustable vs non-adjustable" rocker arm confusion once and for all, b/c I'm getting varying claims from all directions about it. My understanding (correct me if I'm wrong) is that if you have threaded rocker studs with a lock nut and ball washer on top of the rocker arm (my oem Ford), that is an adjustable setup.

The studs that are 5/16" thread on top are non-adjustable rockers. They have a shoulder where they transition to 3/8" diameter. The adjustable rockers have a 3/8" thread and 3/8" locking nuts. Both styles have ball washers, the former having a 5/16" hole and the latter a 3/8" hole.

 

[Rockstar Bronco]

The studs that are 5/16" thread on top are non-adjustable rockers. They have a shoulder where they transition to 3/8" diameter. The adjustable rockers have a 3/8" thread and 3/8" locking nuts. Both styles have ball washers, the former having a 5/16" hole and the latter a 3/8" hole.

These are Flo-Tek heads with 3/8" chrome moly studs, top to bottom.

 

[73azbronco]

You have to be a paying contributor for us to see pics. Like $12 a year.

You say verified timing, have you placed #1 on TDC, verified by watching valve train with valve cover off? Then step through rotation and watch where dizzy is pointing at TDC for #1?