Here's the deal. 02 lq4, 88k miles. It is mostly stock with intake and cut out cats, but in the future I plan to do a turbo setup and make 500-550 on say 8-10psi from small twins or a larger single.

Couple months ago I had an issue with really bad gas, and the truck wouldn't start up easily at all. The last of the 3 days that I tried running the tank of gas out, I had some backfiring through the intake trying to start it, and apparently bent 3 pushrods pretty severely in an S shape. I drained the gas, replaced all the pushrods, injectors and plugs and it seemed okay again with a little more valvetrain noise.

I've been through 3 or 4 more tanks of gas now and it seems that I must have a bad lifter, the noise is very noticeable on cold start and is still noticeable up until about 3krpm even when warm. Also the last couple of days the oil pressure gauge has started to flicker rhythmically with engine rpm, anywhere under 1500rpm and levelling off normally around 2000rpm.

So I figure that if the lifter is this bad, it has probably damaged the cam. I dont want to disassemble the truck without having most of my parts on hand first to limit downtime. So I am trying to plan what to order ahead of time.

1)For the cam, I was thinking of throwing an ls6/z06 cam in because people here say you can get them cheap. But I'll be damned if every time I bid on one on ebay the bids skyrocket to almost 200 bucks. Even if I were okay with paying that for a stock cam, there are never any with buy it now, and I dont have time to sit by the computer at auction close to try and win. Since I have forced induction plans, what recommendations do you guys have for a budget cam? I would not be opposed to buying a custom grind or a regrind like some of the people sell here and on ebay if the specs will be more favorable than the stock cam, but less than a new comp cam etc. I do not want an aggressive cam as I want a smooth idle and good driveability with no surging or dying, though a moderate lope would be fine.

2)FOr the lifters, I see LSX Performance on ebay selling some "GM High performance lifters". Are these anything better than stock? Are they ls6 or ls7 lifters or something? Any other recommendations for lifters (again on a budget, not looking to rev over 6krpm).

3)I've also read that the plastic lifter trays should be replaced, whats the best source for those?

4)Since I have to pull the heads, I thought about changing the valve springs and possibly the valves. Everyone talks about the ls6 yellow valve springs, anything better recommended? What should I expect to pay? Best source for these? Again, no aggressive cam to worry about.

5)I've read that the ls6 valves are superior to the stock valves. Do they fit my 317 heads, and if so, is it worthwhile to change them when I am doing the springs? What should I expect to pay for these? Best source?

6)Head bolts and head gaskets. Other than autozone/etc., any recommended brands or suppliers? Upgraded head gaskets that are not terribly expensive would be a good idea since I plan to go FI.

7)I see a whole slew of parts suppliers sponsoring this forum as well as selling on ebay and the internet. Who would you guys recommend to buy most of this stuff from, preferably all from one shop? I am hoping to stay in the $500-750 range for this entire repair/project. I dont care if some of the parts are used...

8)Back in the summer I was trying to pull my passenger side exhaust manifold and could not manage to get the dipstick tube to pull out of the block despite all my pulling and wiggling. I did not remove the starter to try and pry it out there, though. I am not sure if I can pull the head with the manifold and dipstick tube still there, so is there some trick to this? My truck is AWD so of course I would like not to have to pull the oilpan etc.

Thanks in advance for all your help guys. I build rotary engines but I am a little out of my element with the newer gen3 engine parts interchange and such.

 

1)For the cam, I was thinking of throwing an ls6/z06 cam in because people here say you can get them cheap. But I'll be damned if every time I bid on one on ebay the bids skyrocket to almost 200 bucks. Even if I were okay with paying that for a stock cam, there are never any with buy it now, and I dont have time to sit by the computer at auction close to try and win. Since I have forced induction plans, what recommendations do you guys have for a budget cam? I would not be opposed to buying a custom grind or a regrind like some of the people sell here and on ebay if the specs will be more favorable than the stock cam, but less than a new comp cam etc. I do not want an aggressive cam as I want a smooth idle and good driveability with no surging or dying, though a moderate lope would be fine.

The Z06 cam would be perfect for a turbo setup. They are well known for being turbo friendly. Keep an eye on the classified section here and over on ls1tech. They pop up occasionally, and usually sell for $150 or less.

2)FOr the lifters, I see LSX Performance on ebay selling some "GM High performance lifters". Are these anything better than stock? Are they ls6 or ls7 lifters or something? Any other recommendations for lifters (again on a budget, not looking to rev over 6krpm).

There's two types of lifter upgrades available. The LS7 lifters can generally be had for about $100 or so. Check Scoggin Dickey, they are a site sponsor www.sdpc2000.com

There's also the Cadillac Racing lifters, but they are much more expensive and are really only worth it if you plan to turn 7000 RPM or up. These usually go for about $300 a set. Not really worth it unless you're building a road course engine that sits at high RPM for long periods of time.

3)I've also read that the plastic lifter trays should be replaced, whats the best source for those?

I don't see any reason to replace those.

4)Since I have to pull the heads, I thought about changing the valve springs and possibly the valves. Everyone talks about the ls6 yellow valve springs, anything better recommended? What should I expect to pay? Best source for these? Again, no aggressive cam to worry about.

$50-60 will get you a new set. Scoggin Dickey carries them too.

5)I've read that the ls6 valves are superior to the stock valves. Do they fit my 317 heads, and if so, is it worthwhile to change them when I am doing the springs? What should I expect to pay for these? Best source?

I can't answer this question for you, but again, check SDPC...they should be able to answer your question.

6)Head bolts and head gaskets. Other than autozone/etc., any recommended brands or suppliers? Upgraded head gaskets that are not terribly expensive would be a good idea since I plan to go FI.

Unless you want to go thinner or thicker to change your CR, stick with the stock gaskets. They are very good. I'm running stock gaskets in my boosted 408 with no problems so far.

7)I see a whole slew of parts suppliers sponsoring this forum as well as selling on ebay and the internet. Who would you guys recommend to buy most of this stuff from, preferably all from one shop? I am hoping to stay in the $500-750 range for this entire repair/project. I dont care if some of the parts are used...

For OEM parts SDPC is probably gonna be your best bet. If you go with an aftermarket cam or heads or whatever, a lot of the performance shops will sell OEM gasket kits with their stuff. I'd probably get it all from the same place though. You generally save money that way, and if you spend enough sometimes you can get them to throw in the low cost items for free.

8)Back in the summer I was trying to pull my passenger side exhaust manifold and could not manage to get the dipstick tube to pull out of the block despite all my pulling and wiggling. I did not remove the starter to try and pry it out there, though. I am not sure if I can pull the head with the manifold and dipstick tube still there, so is there some trick to this? My truck is AWD so of course I would like not to have to pull the oilpan etc.

The dipstick tube is easy. There's a 15mm bolt that secures it to the cylinder head, then it should just slide up and out. You don't need to unbolt anything lower on the engine.

 

When you tear it down, I recommend turning the engine over by hand and making sure that all of the pistons are coming all of the way up. It is possible that a connecting rod got slightly bent if the engine hydrolocked due to the cylinders filling up with unburnt fuel. This could cause a piston slap from the piston rocking in the cylinder, (which may be your noise) yet the engine could run fine...I've seen it before on some different manufacturers vehicles.

 

Thanks for the thorough reply. I am looking at that fellow's cam copies/regrinds in the FS section and will likely get one of those unless there is some reason not to. Then check with your recommended supplier for the rest.

I had the 15mm bolt out. I pulled, wiggled, twisted, and it would NOT come out. I as afraid I would break it and then be stuck with a non driveable truck, so that's where I stopped. I don't think that anything short of a prying method would get mine out. My truck was from up north, and there is light rust on some of the frame and suspension parts.

 

Ahh that would make sense. Well that's all it is *supposed* to take to get the tube out

 

Interesting. Would this condition go along with the oil pressure issue I am seeing? My engine always made 60+ on cold start, 40 at idle, 60 by 2krpm and 75+ above 3000. Now I am seeing the same pressures, but a flickering guage anywhere below 2k. To me, that seems more like a lifter that isnt maintaining proper contact and losing pressure for a split second.

 

If there is a bearing issue it could affect the oil pressure, or the oil may be diluted with the unburnt bad gas...did you change the oil after all of this happened? That could be the whole problem (that would be way to easy and cheap of a solution though lol)

*EDIT* or the diluted oil may have affected the oil pressure sender...there's a few different scenarios it seems

 

I am very sure that I do not have any fuel dilution issue, it's a GM v8 and not a rotary, lol.

I compression tested each cylinder and changed the sparkplugs right after the pushrod issue, and there was no excess fuel being blown out. The only wet plugs were the 3 that were associated with the 3 bent pushrods, because fuel was being injected but not much air was being let into the chamber.

I run full synthetic and it feels and smells normal, no excess fuel dilution.

Would a bearing issue not affect oil pressure across the board, rather than on a per-rotation basis?

 

Lifters....... LS7, stockers, Melling, Comp (Direct replacement). Do not touch the Comp R's!!!!!!!!!!!!!!

 

for 115 bucks, these "gm performance lifters" from lsx performance on ebay are looking nice to me...