lower intake disassembly and diagnosis

Don W.

Don W.

Stab it and steer it
Re: lower intake disassembly and diagnosis

The "stoppers" I'm talking about clip on the rockers so they don't spray oil. That way you can run the motor with the valve covers off and check for loose rockers.

Just watched the vid. I'd say, FWIW, my truck ticks louder than that.
 
Quickstop [UK]

Quickstop [UK]

Combating adversyty.
Re: lower intake disassembly and diagnosis

I just had the privilege of riding in a stock Sy and there was none pf the ticking that mine has so I have to conclude that there is something amiss.

850s on order - I'm into it now anyway :)
 
Quickstop [UK]

Quickstop [UK]

Combating adversyty.
Re: lower intake disassembly and diagnosis

randy merritt said:
1.52 ratio rocker sound like non-self aligning Comp rocker. Don't want to jump in with BS, but do you have guide plates? I just went through this on a Vortec swap. Rockers I bought with set were Comp stamped steel 1.52 roller tip rockers. These are non-self aligning. I am having to order a set of full roller, self-aligning 1.5 rockers. Don't know if this helps or not. BTW, I did a lot of reading and research before my head, cam, injector swap (underway), and best I can figure, the 875 lifters are a better design, but are noisier. I decided to go with the 850 lifters.
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Thanks mate.

I got the Comp Cams full roller 1.5s with self aligning tips. Initially the 1.6s I had were not seating on the valve and were pressing the spring cup. I thought that might have made the noise but when I started it, there was little to no improvement.

I concur re the 850s. I did the same research and went with reliability/strength but it sounds pretty crappy with the 875s.
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: lower intake disassembly and diagnosis

If you are lacking performance, it could also be a bad valve/guide. I had this happen to me on a freshly built 350 in my old 74 Monte Carlo. I had spent a few k on the motor and couldn't get it to run right nor could I get rid of the ticking sound. I got my Vette and the heads went to the motor for that. When the ticking was still there the heads came off and discovered the loose valve. It was re machined and the valve/guide replaced and after 10 minutes of run time or so it was back. I had to throw the heads away and have the original heads from the Vette re-worked.
 
Quickstop [UK]

Quickstop [UK]

Combating adversyty.
Re: lower intake disassembly and diagnosis

God I hope it's not that. Hmm. You've got me thinking. Can I check with the heads in the truck? Would a comp test tell me anything? Can I do the comp test without the cam/valvetrain set up?

I was thinking maybe the valves are closed so I would get max compression anyway. WIll give it a go....
 
bezerk

bezerk

New member
Re: lower intake disassembly and diagnosis

you can't do a compression check if all your valves are closed. leakdown test is what you can do
 
Quickstop [UK]

Quickstop [UK]

Combating adversyty.
Re: lower intake disassembly and diagnosis

Update:

I got some new 850s from eBay and did a bit more reading on here. I decided to install a set of used good GM lifters after reading about failures of the 850s and 875s. The 875s I removed had two very easily compressible lifters which should not happen unless they are bad. I read that a few people have had bad lifters and some time in syty chat convinced me not to use the 850s either – they are not actually made by GM.

Corvette Forum issues

I replaced the lower but decided to pull it almost immediately. I wasn't happy with the first install of my lower intake for two reasons:

1) I didn't follow the torque tightening sequence (didn't know there was one)

2) It looked like the coolant passage at the front dvr side was not sealed properly.

Sooooo..

I pulled the intake and replaced the gaskets and tightened it all correctly.

The torque sequence for the lower intake is:

FRONT PASS side: 11, 6, 4, 2, 8, 10
FRONT DVR side: 12, 5, 1, 3, 7, 9 (edit – I need to verify this – it’s in the service manual if anyone has one but I don’t have that here. PM me and I’ll update this post)

I did a comp test after I had adjusted all the valves according to the TDC E/I then BDC E/I adjust method. NB – stock lifters require 1 full turn past 0 lash. I was a bit nervous with that but I got 165lbs compression on number 1. :woot:

So I connected everything else back up and started the truck after fighting with the distributor for ages. (Dis gear upside down.... :oops:)

Got it in eventually...

Truck ran great! I had the valve covers off and could hear a ticking - dammit! I then got my engine stethoscope out and heard it coming from E/I #3. The lock nuts turned out to be loose so I adjusted them until the ticking stopped.

I think that it has gone! Problem solved!

I replaced the valve covers as well and found that I can remove the driver side without dismantling anything else so I can adjust as required.

Conclusion: The new 875s I got didn’t work 100%.

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Interesting piece of trivia.
The Royal Flight in the UK for the Royal Family doesn’t fly with any brand new parts on the aircraft. Due to the mean time before failure curves, they take parts, use them and once they have been used for a period to make sure they haven’t broken immediately, they stick them in the Royal aircraft.

I imagine Obama and other VIPs do the same.

One to consider when buying used vs new parts. I’ve had bad sensors and now lifters straight out of the box…..
 
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blacktyaffair

blacktyaffair

Donating Member
Re: lower intake disassembly and diagnosis

Congrats on getting the pos running quietly! You sure do have some bad luck with new parts maybe you'll have better luck from now on.

Upside down distributor gear? Now that is special.
 
bezerk

bezerk

New member
Re: lower intake disassembly and diagnosis

bundie said:
:rotf::rotf:

glad you fixed the noise mark!!

now go to santa pod and break some shafts!
Click to expand...

he needs to bring that thing to drachten, i spent many hours on that truck, brought it over twice, no he should give me the joy to blast the cladding off of his truck.

Cheers Mark for your steadyness to fix your truck:tup:
 
cat-vi

cat-vi

Ty Wannabe
Re: lower intake disassembly and diagnosis

Way to go, very interesting, BTW I dig the "boost parking" video, even the dog was wondering what the f... :)
 
Raist103

Raist103

Engine Killer, iPhone Killer, Lawnmower Killer
Re: lower intake disassembly and diagnosis

maybe im having a brain fart but what the hell is E/I #3
 
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