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Davect06607 09-19-2013 09:31 AM

rebuilt Chevy 350 break-in issues
 
Hello all, let me start out by saying Thank You. I have been readings articles/wiki here for a few years and have learned alot of great information.

I decided to rebuild a chevy 350 for my '85 k10. Started with a 2 bolt main. Disassembled the block and took it to a trusted enigne shop. Block was cleaned, bored .040 over, crank polished, rods recondition, and cam bearings installed.

Block recieved all new bearings, oil pump, Summitt Pistons w/moly rings, freeze plugs, double timing chain. Pistons were just oem replacements and fel pro head gasket.

For cam, went with a Comp Cams Xe 262h, Hydraulic Flat Tappet. New hydraulic lifters, pushrods. Plenty of comp cams cam break in lube was used, 2 packets.


I reconditioned a set of 993 smog heads with; 2/3 angle valve job,new valves, ptfe seal w/guides cut, comp cams 1.254'' spring/locks/retainers, intake & exhaust ports matched, 1.52 roller rockers w/polylocks (was used). Studs was not replaced, threads were good.

Stock 70's GM dual plane aluminum intake manifold.


Problems begun when attempting to break in cam. I had a edelbrock carb with stock setting on the shelf for years, been using a pig rich holley. went with the edelbrock for first start. No good, all valve timing was off, and barely had any compression. Readjusted timing again and again and again. This whole time turning the engine over by hand, wiping all my lube off my cam.

Cranked aqnd cranked (eventually killing 2 batterys) the engine trying to get it to fire. Confirmed fuel and spark. Couldnt get it to catch at all, even with starting fluid. Threw the edelbrock across the garage floor and tossed in the gas loving Holley and a new ebay distributor.

Voila she rumbles to life, but sounds like ****. Adjust timing to 32' at 2250 rpms, ran it like this for 10 minutes. My assistant was blipping throttle and she died, went to restart and starter isnt engaging.

A week later, readjust starter/flexplate spacing. Start it up, and hear a loose rockers. Pull valve covers and readjust them all once again. Total run time maybe 5 minutes at 2200rpm.

I am about to mess with her again tomorrow, gonna try to get at least 10 more minutes of break in completed. Then change oil (Rotella-T w/comp cams additive was used for break in) and try to get her to idle. Once she is idling, pull valve covers and readjust rockers, and confirm any wiped lobes.

Basically what are my chances that the cam is wiped out? Im giving myself 50/50.

Sorry for the book, but wanted to include everything, and thanks again ALL. :welcome:

bygddy 09-19-2013 11:54 AM

How are you trying to set valve lash at this point?
First and foremost confirm your firing order, there is almost zero chance that an untouched stone stock edelbrock wouldn't have fired right up and run fine. Love em or hate them, they do work.....
As for your valve lash, here is a post that I def stole then copied and pasted, I use it on anything with a smallesh cam and once the cam is broken in I will go back and use a cut open valve cover and do it the old fashioned way.
These are the 2 things I would look at, confirm firing order, reset valve lash, then drain oil, add a comp additive PN#159 and rottela 15/40
Then get it fired and back to 2500+rpm for a complete 20-25 min......then drain oil, replace filter, another comp additive and new oil and drive it.


" With the engine OFF and spark plugs removed so that you can rotate the engine with less effort.1. Get #1 piston to compression TDC, Cam gear at 12 o'clock crank gear at 12 o'clock.2. Adjust the intake valves on cylinders 1, 2, 5, & 7 by loosening the rocker nut until play is in the pushrod then just take the up and down play in the pushrod and tighten the rocker nut 90 degrees3. Adjust the exhaust valves on 1, 3, 4, & 8 in the same manner.4. Rotate crank 360 degrees to get cylinder #6 to compression TDC, Cam gear at 6 o'clock and crank gear at 12 o'clock.*5. Adjust the intake valves on 3, 4, 6, & 8 in mentioned manner6. Adjust the exhaust valves on 2, 5, 6, & 7Getting the '0' lash is the same as I posted originally. Use the "up and down" rather than "spinning" the pushrod. You will find it to be much more accurate."

Davect06607 09-19-2013 03:53 PM

I will try that method again for valve adjustment. This was the method i used to do the first adjustment on the engine stand. Was doing the "adjust #1 rockers when #6 rockers are moving" method now. Also read about the polylocks, as in getting another 1/8 or 1/4 turn once set screw is secured.

Good idea on changing the oil again, i will definetly do that as well.

Firing order was confirmed, found TDC on #1 then dropped distributor and ran wires from there.

Thanks for the help, Momma has been getting after me lately, she wants her driveway back!

bygddy 09-19-2013 05:07 PM

Quote:

Originally Posted by Davect06607 (Post 1773434)
I will try that method again for valve adjustment. This was the method i used to do the first adjustment on the engine stand. Was doing the "adjust #1 rockers when #6 rockers are moving" method now. Also read about the polylocks, as in getting another 1/8 or 1/4 turn once set screw is secured.

Good idea on changing the oil again, i will definetly do that as well.

Firing order was confirmed, found TDC on #1 then dropped distributor and ran wires from there.

Thanks for the help, Momma has been getting after me lately, she wants her driveway back!

At tdc (compression) #1 pull your dist cap and confirm the rotor is facing #1
You may be off a tooth or 2 there.

bygddy 09-19-2013 05:10 PM

And last but not least, the "spinning" the pushrod method almost always results in exsessive lash. Its not as easy as it sounds.
Use the jiggle up and down method, its going to be more accurate in your case.
A little loose is better then a lot tight.....it can be reset after cam break in.

Davect06607 09-23-2013 07:39 AM

Quote:

Originally Posted by bygddy (Post 1773626)
And last but not least, the "spinning" the pushrod method almost always results in exsessive lash. Its not as easy as it sounds.
Use the jiggle up and down method, its going to be more accurate in your case.
A little loose is better then a lot tight.....it can be reset after cam break in.

Ya I made this mistake the first time around, had no compression in the engine, when cranking by hand. All the valves was too tight.

Davect06607 09-23-2013 07:52 AM

Update: Changed oil & filter, added more Comp Cam additive. Did my valve timing with the method suggested above (threw out polylocks and used oem nuts, #2 cylinder rockers had came loose again).
Confirmed firing order once again. Fired her up, set timing to 32* at 2250-2500 rpms, ran for 25 minutes with no issues! Temp was not an issue, highest i seen was 194* (185* t-stat).

Finally a full break in completed. She sounds real good, real good throttle response. Now I am on the positive side that the engine is ok with no wiped lobes, we will see though.

Thats all i got done, next is to change oil & filter again. Then get the Holley carb fine tuned so she'll idle. Once i get the idle established, I would like to adjust the valves again when running (and to confirm any wiped lobes)

Before that I have to figure out this starter dilema, got the classic grinding with occasional start. With a Delco oem starter and an aftermarket mini. Tried swapping in a variety of shim and still same. End of the week, I'll be looking into that more.

Do you recommend another bottle of comp cams additive with next oil change?

techinspector1 09-23-2013 10:27 AM

Quote:

Originally Posted by Davect06607 (Post 1781962)
Do you recommend another bottle of comp cams additive with next oil change?

Yep, ~1200 PPM ZDDP for the rest of your life..... (or until you come to your senses and install a roller cam). :thumbup:

1Gary 09-23-2013 08:48 PM

Look into nicked teeth on the flexplate.

Davect06607 09-29-2013 11:47 AM

UPDATE: Momma is happy once again, lol. She got her driveway back.

Finally got to spend another day on the truck.

Starter issue resolved, spacer only on outward hole to move starter closer to flywheel (all teeth are still good, luckily).

Spent a few hours on the Holley 650 carb and getting it too idle. Had fuel dribbling from primary boosters, Floats levels were good.
Ended up being not enough initial timing, so i was compensating with the idle adjustment which was pulling the fuel from the booster.
But for **** and giggles, I threw the edlebrock 1405 back on. And voila! Runs beautiful now with this carb.

Initial timing at 18*, all in with 36* by 3,200rpm. Used the middle springs from an Accel HEI spring kit.

Been driving it the past two days, trying to get some miles on her. It is running excellent, Im so use the old worn out 6 cyl (350 w/2 low comp. cylinders).
Having really laid into her yet, I'll give it a few more weeks for that. But she wants to spin the 33's, even with the 3.08 rear end. This cam has a bit more 'lope' then I thought it would have, still sounds incredibly good though.

I plan to rack up a few hundred miles like this then pull v.covers once again to adjust valves while running. And I'll play with the timing a bit more then.
I would be surprised if I have a wiped cam lobe now, but we will see.

Took the truck to work this morning, and had to crank the truck over a few times to start. Fuel pressure, I am losing fuel pressure somewhere when engine is off. The gas filter is empty (fuel draining back down the line) once she has sat for a few hours. No apparent gas leaks anywhere. Running a mechanical pump to cheapo regulator (set at 5psi) to gas filter, to edelbrock carb. Any thoughts?

bygddy 09-29-2013 11:57 AM

Quote:

Originally Posted by Davect06607 (Post 1798314)
UPDATE: Momma

?.........

Davect06607 09-29-2013 12:13 PM

Quote:

Originally Posted by bygddy (Post 1798330)
?.........

lol, damn. You saw that.

bygddy 09-29-2013 12:52 PM

Quote:

Originally Posted by Davect06607 (Post 1798386)
lol, damn. You saw that.

Lol.....i have hit "enter" myself by accident......even worse when your texting the wife and hit send by accident when your trying to erase something stupid your about to send.
Glad you got it sorted out and running well. Your timing is likely pretty close as it sits now. I have a 1405 on my 306 in my Comet, I borrowed a 650DP last week just to try it and honest, the edelbrock seems a little smoother, easier start up etc, maybe even a touch crisper, but good lord it feels like its down a cyl in comparison to the Holley.....its sooooo much stronger with the 650 on it. Good luck and enjoy it, its satisfying when it comes together.

1971BB427 09-29-2013 02:03 PM

I think you'll be fine without any additive to oil, but that depends on your oil of course! Too much zinc is bad also, so don't go overboard on breakin oil or additives! I use Brad Penn oil in my flat tappet engines, and I put lots of miles on them. It's the old Kendall factory, and is made to specs for early flat tappet type engines.
I'd want to know the location and positioning of the various components to comment on the fuel draining out. Offhand it sounds like maybe the needle on the floats isn't sealing well, which will let fuel leak into the engine, but also let fuel siphon back to the tank.
I'm still not a fan of adjusting lifters with engines running. It's based more on hearing them click, than really accurate adjustment. I agree with the spinning the pushrod to set lash; as that almost always ends up in things being too tight. Make sure you've got 1/2-3/4 turn after zero with these crummy lifters every cam maker supplies today. The wire clips will pop out if they don't have the extra turn, and then things will get ugly! I've had problems with them, as it took me awhile to understand what was happening to these late style lifter clips.

prostreet6t9 09-29-2013 03:01 PM

[QUOTE=1971BB427;1798657]I think you'll be fine without any additive to oil, but that depends on your oil of course! Too much zinc is bad also, so don't go overboard on breakin oil or additives!

X2! Dont read to much into the whole oil thing. I've done many non roller engines that have gotten lots of miles with no camshaft failures.

No doubt roller cams are the best.. But the Hyd and solid cams have they're place also. I do use some additive for break in but after the drain and refill I've never used any more additives.


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