88 TBI

Hello everyone I have a rather odd question. It's more of a... has anyone ever done this before and what were the results kind of a question than a question where I actually need the professional engine builder machine shop dissertation. I already know that answer, what I'm asking / looking for here is anyone who has done this and what were your results. Ok here we go and I'm not hopeful... Lol

I was planning on doing a timing chain on my 88 305 TBI and I started hearing a noise. It sounded like a knock and it was coming and going. If the engine sat there idling it was fine and sometimes if I revved it it was fine but sometimes it had a very weird knocking sound. So today I was able to find someone knowledgeable and had them give it a listen. Turns out the noise was coming from the lifters, apparently they are bleeding off while it's running. I then noticed as soon as I shut the engine off all the valves close and those valve springs are from 1988. The engine has good oil pressure 30 to 45 PSI around 15 PSI at idle and from what I can tell all the push rods are spinning. The engine was not ticking it just had a weird knocking sound. We finally determined the sound was the lifter knocking on the cam. It may sound strange but we pushed on the push rod end of the rocker arm and we were actually able to partially compress the lifter while it was running and there was the noise. It's actually not a knock or a tick it's kind of like a hollow donk donk donk... Sorry best I can do... Lol

With that said I have a brand new set of lifters with all the assembly lubes, the valve springs on this thing are so weak you can push them down with your hand so they would be perfect for a second break in. I was thinking put the new lifters in, throw the timing chain on spin it over and see what it looks like. I'm thinking if the push rods are spinning I'm gonna go with it. I even have an old Performer TBI intake I'm going to throw on top...

SO if anyone been been successful or unsuccessful at swapping new lifters onto a good old cam please let me know.

8t2 z-chev

I Put new lifters on an old cam once as a teenager in 1985 and got away with it-tried it a 2nd time and glitter in the oil,so that one had to come right back apart for a proper new cam and lifters...Is this in a pickup?-cars had roller cams starting in '87

ShiftyCapone

iTrader: (7)

New rollers are fine to use on your motor. One of the many blessings of hydraulic rollers.

88 TBI

Yes this is in a pickup and it's a non-roller cam. I kind of have a process I'm going to go through and if anything looks sketchy I'm just going to abort mission.

Right now it's more of not having a proper place to work on it.

88 TBI

I'm pretty sure it's a non-roller cam.

ironwill

You can't put new flat tappet lifters on a used cam; they'll wipe and send metal all throughout the engine. If you're certain you don't have a rod knocking, at least replace the cam and lifters (and the timing set) as a unit.

All that being said, from the remainder of your description, it sounds like you may be facing a total engine rebuild.


Whatever you decide, good luck going forward.

T.L.

I've always heard that you can put new lifters (flat-tappet) on a *GOOD* used cam, but not old lifters on a new cam...

88 TBI

Hello and thank you for your reply. Number one you absolutely can do that and it can work if all conditions are satisfied. If the cam is not damaged or worn and it's just the hydraulic part of the lifters they can be replaced IF THE CAM IS NOT ALSO DAMAGED.

Unfortunately, you're doing exactly what I asked people not to do. I've been an automotive machinist my whole life and I understand the proper way to do things. Again, what I was asking is if anyone has ever done it and what were the results. Just to clarify, I AM NOT asking the proper way to do it, I was asking if anyone ever did it this way and what were the results either way.

88 TBI

I've heard exactly the same thing over the course of my life and I know people who have done this, some with good results some not so good. I didn't really get into it with them why it did or didn't work it was just things I heard over the years.

​​

T.L.

To answer your original question directly, when I changed the cam in my F*rd to one with different specs, I gave the old cam (Comp 268H) to a friend. It had only 4,000 miles on it. He installed it in his freshly rebuilt 302 along with new lifters. He's never had any problems with it...

88 TBI

Thank you for that very direct, clear and concise answer. That's all I was really looking for. I truly believe if the wear pattern on the cam is good and you follow proper break in procedure as if it were new there should be no problem.

Now with that said the oils today are different so I would definitely back way off on the spring pressure, ZDDP it and coat everything with a mixture of cam break in lube and ARP moly lube. It's only running at 1500 RPM for 20 min and if you really want to have a successful go I would do everything to help it live.

I think every situation is unique but I would say in most failed cases the cam was also worn too far along with the lifters and they just failed to see it or saw it and didn't know what they were looking at.

​​PS : I'm very sorry to hear about your F*rd problem... We all have something, mine is called worn out timing chains on a J*#p.... Which smells shockingly familiar except the cams on the Joop are ok... The lifters were ticking and the 16 ft of chain however is not...

T.L.

My F*rd runs great. I just wanted a different cam. Of course it would run even stronger if I had known back then what I know now...

88 TBI

Sir you just said something right there... Hindsight is like a freight train right in the face...

88 TBI

So I must give an update, it rained early yesterday and looked like it was going to rain all day so nothing got done.. well as far as taking things apart. I went to see an old engine builder friend of mine and when he pulled out his melling book and.... Well we started looking at cam specs and when he looked up a stock cam for a 1988 305 pickup truck.... I have no words... I mean in all my years I've never really had the interest to look up the exact cam specs on a stock cam for a 305. 🤢🤮

He recommended something that's a bit of an old school torque cam ( MTC-1 ) and it looks like it would work very well. I can't believe I can get it for $86 shipped right to my house from AutoZone online. By using their 20% discount and just seeing those stock cam specs 😱 that was enough to push me over the edge. I think a full valvetrain swap is in order at this point...

I guess if anyone has used this MTC-1 cam please let me know. I would still like to know about my original question if anyone has ever had success with the lifter swap only ...

Tom 400 CFI

I have swapped lifters only with fine results when a lifter failed (collapsed). I'm not sure how it's relevant though, if you're changing the full valve train?

sofakingdom

iTrader: (1)

The MTC-1 is just a generic copy of a copied generic copy of a generically copied copy of a generic cam from the early 70s. 204°/214°, .420"/.442" or some such. It's also the Summit 1102, the Edelbrock Performer, and any number of other generic part #s. Works fine in the LG4 and L03. You're not gonna go out and run with the Pro Stocks or anything like that, butt it'll be a nice bump, as long as you also do the exhaust; EVERY PIECE from the heads to the street. Otherwise nothing you can do to the cam will make much difference, except if you put in too much, it'll slow the car down from stock.

Fast355

iTrader: (2)

In a truck that 305 with TBI would probably run better with a CCS-2 or CS-274 cam. The ubber basic 350 camshaft that came in the almost every small block in existenc including the 350 TBI truck engines and the 305 Crossfire TBI cars. While the 204/214 grind is mild, it is not quite mild enough that the 1988 TBI ECM will want to run it correctly with the stock tuning. The 350 cam being 194/203 @ 0.050, 112 LSA and 0.390/0.410 lift will run considerably better than the 178/194 @ 0.050 on a 109 LSA with 0.350/0.385 lift that the 305 came with. The 350 cam will also not require a spring upgrade which the 204/214 would. The slinkies GM used for flat tappet cammed truck valve springs just do not have the seat pressure and open pressure to adequately control even that ancient 204/214 grind. The basic old 350 cam is very similar in specification to the 191/196 @ 0.050, 111 LSA, 0.412/0.428" lift L30 305 Vortec that was recycled out of the iron head LT1 and the 350 Vortec truck engines.

88 TBI

Yes this cam has been around since the dawn of time under every name and part number that has been mentioned. I bought the springs that go with the MTC-1 accidentally a few years go so I was surprised I had the correct set. They were supposed to be stock. I also had Dynamic EFI upgrade my ECU about 3 years ago so the stock tune is long gone. I still need some help with understanding the EBL and Tuner Pro but whatever tune was in when it came back works very well so far. I believe I talked with you about that in the past. I also installed my TBI Performer intake that I had for over a decade. My TJ-11's are still sitting on the shelf waiting for me to figure this Flash EBL system out.

By the way, I'm in the Wilkes Barre Pa area if anyone wants to give a hand with some tuning tips it would be GREATLY appreciated. I even offered to pay but no takers. I should have it ready to fire up today so we shall see how it goes.

88 TBI

Hello and thank you for the reply. I know exactly what you are saying, after I thought about it and compared the cost of the new cam ( $86.00 shipped ) vs. the pitiful cam specs on the stock cam and I realized I could get something so much better for $86.00 so it was a no brainer... I was thinking the cam would be much more. I also have an engine that I'm building for the truck but it's not ready yet so that was another cost factor.

Anyway, with all that said I spent the past few days cleaning, painting and checking everything that might cause any issues. I'm happy to say the old cam / lifters, timing chain set, timing cover and valve springs will all be heading for the scrap bin...

sofakingdom

iTrader: (1)

"Stock" covers a fair amount of ground when it comes to springs. Stock TBI springs, or Vortec ones, aren't even enough for a stock TBI cam; butt the old stock "Z28" ones, will work fine on that other cam.

Main thing you gotta be careful of now, is break-in. the engine MUST NOT idle, or even go much below 2000 RPM, for the first 5 minutes or so of it running. Which means, NO half-assing ANYTHING; NO "I just wanna make sure it runs"; NO slap it together and hope for the best; NO randomly stab the distributor and then be out in the ozone with the ignition timing; NO NO NO NO NO NO NO NO. Gotta be PERFECT the instant you first hit the key.

Check whatever timing mark setup your new cover has. The tab MUST match the mark on the balancer, otherwise your "light" and all that, is USELESS. Your stock tab is welded on at about 12:30 to the crank CL; butt most of the ones that bolt on are designed for the old-skool location at about 1:30. This gives an automatic instant infallible ERROR of around 30°; meaning, if you use "light" and "mark" and all that, and you "think" your timing is at say 10° advanced, it's REALLY at 20° RETARDED. It will run like crap and overheat like a Sumo wrestler in a wool winter workout suit lifting weights for an hour in an un-air-conditioned gym, except it'll only take about 2 minutes. Also, if your new on is "krome", be prepared for all kinds of leeeeeeks, at the front seal, the front oil pan rail, and even the main gasket. I'd strongly recommend re-thinking the idea of replacing it. You'll be money and trouble ahead if you just clean up your old one.

88 TBI

First off I started this project last Wednesday with the intentions of covering every single thing you mentioned and then some.

Back three or four years ago I bought the valve springs for the STOCK cam but I bought the wrong ones they are actually the Z28 springs that go with this MTP-1 cam. I found a stock stock stock timing cover and balancer off another 305 so trust me I didn't put any aftermarket krome crap on this engine. The old timing cover had a hole cut in it when the harmonic damper slipped and slid back against it. That's been gooped up for about 15 years so I scrounged up another stock balancer and cover. The timing chain and gears are a NEW Cloyes set.. I don't really understand what you're saying about the old stock Z28 springs on the other cam?? The MTC-1 cam?? And forget the Z28 nonsense they're Melling VS-380 springs for whatever cam they're recommended for.

I'm also with you on all the startup procedures, basically fire it up and get it up to about 1500 RPM for 20 minutes while checking everything. The harmonic damper is set to zero on the timing mark and I even painted the groove white on the balancer.. I dropped the distributor in pretty much exactly the way it came out and the plug wires lineup perfectly. The whole TBI had a new kit put in it also. I'm a little bit OCD when it comes to this stuff and I could be a little **** about cleanliness so trust me there's a reason it's taking me a week to do this project. Not sure I mentioned I also put an Edelbrock performer TBI intake on it with a transdapt TBI spacer. There has just been a lot of little modifications due to what I've installed.

Keep in mind I'm an automotive Machinist not so much a mechanic but I've been doing this for many years so I'm not really a noob EXCEPT when it comes to the dynamic EFI. If you'd like to be helpful with that please let me know I pretty much have everything else under control....

So far I'm waiting on a cap and rotor and a few other minor details and it should be ready to fire off. Also thank you again for your concern and helpful tips on the whole process, I really appreciate it.

sofakingdom

iTrader: (1)

Yes. They work just as well on any stock cam including the TBI ones, so there's no problem with using them in that way. They're adequate for the Melling ("other") cam as well, although if the ones you have now have lots of miles on them, I'd go ahead and renew them anyway. Not sure what the specs for the Melling springs are (being "replacement", not even sure whether they publish them after the manner of "performance" mfrs) but you can check them easily enough with nothing more complex than a scale, some way of measuring their height, and a drill press. Ideally you want about 110 - 120 lbs at 1.700" height (the nominal stock installed height), and no more than about 300 lbs at 1.200" height (.500" lift). Any spring that gives that sort of numbers will work fine.

When you install them, use "positive" valve guide seals. NOT "umbrella", and the O-ring isn't necessary. Leave off the splash shields and the factory "rotators" on the exh valves. Stack up shims, or use spacers, to get as close as you can to 1.700" installed height without going to any less. Shouldn't be hard to get them all to 1.70" to 1.71" with off-the-shelf parts and a few moments of patience.

Nowadays LS6 springs or the various drop-in upgrades for them, and the Comp "adapter retainers", are another popular spring option; a MUCH better setup than a straight 1.25" OD spring.

Easiest way to line the dist up PERFECTLY is, set the crank to the exact spot you want #1 to fire at (10 or 12° BTDC would be my guess as to a good starting place... I'd rather have slightly too much advance for 1st startup and break-in than any too little) by rotating the crank in the forward direction only to take up any chain slack there might be, pull up on the dist shaft as far as it will go and turn it hard CCW to take up all the slack out of everything in the dist, and adjust the dist body until the little "teeth" on the star wheel line up with the ones on the pickup coil. Tighten it down there, butt leave it loose enough to be able to adjust later.

New stock timing cover is the best way to go. Glad to hear that. I hate "krome" ones. Too bad too many people get all wrapped up in "looks" and overlook common sense. Esp when the base steel under the krome rusts in about a week, and starts blowing the krome off in flakes. Which is one of the most brutal source of leeeeeks with those POSs.

For a 1st startup I prefer to assemble the car COMPLETELY; valves adjusted as well as I can get them (all 16 set on their exact "heel" of the lobe plus ¼ or ½ or ¾ turn depending on what's in it), fluids full, wiring clipped into all its places, hoses tight, air cleaner on, EVERYTHING complete and finished, in place and ready to drive; shut the hood; pour an ounce or so of fuel into the throttles; and reach in the window to crank it up. Kinda symbolic in a way I suppose, even if not "necessary"; always used to amaze customers when I did it like that back in the day with them watching, when they're used to seeing other techs struggle to get a new motor to even run at all, much less be READY to back down the driveway and go for a test drive within 5 minutes of first turning the key.

Can't help you with EBL (Dynamic EFI) if that's what you've got. Instinct suggests you won't need all that much tuning with that cam if it was already dialed in. Lots of other folks have it though so someone no doubt can help you out.