Hi for all,

Last year I mostly rebuilt my 305. It got ported heads, B-Body LT1 cam, 1.6 Comp Cams roller tip rockers (yes, I checked all the clearances and it was fine, I got them for decent price and they should be quality product, so I decided to give them try). I cleaned and reused old lifters. Engine worked fine after first startup - I had heard about cam swaps and how changing the cam would make the car undriveable mess. Nothing like that - car accelerated fine, ran slightly rich, but no other anomalies

After working the engine in with thicker mineral oil I changed to 5W30 FS and I found that lifters started to tick. Actually two of them. When I cleaned the lifters, these were the ones that had most deposits inside too. So I ordered new set of Delphi lifters, changed them, slapped ported Edelbrock Torker II intake on it too (I know, I know, but I had it almost for free and it's almost only aftermarket intake that is about same height as stock TBI intake), and called it a day.

And now the car was undriveable mess - it needed about 10 degrees ignition initial timing for idling acceptably smooth. But it hesitates, has almost no power, backfires and stumbles. I guess typical symptoms of LT1 cam swap and stock PROM. Changing initial timing does not change the driving quality much.

What makes me curious - how the car ran fine before the last two steps? I have no ideas for this.

Second thing that makes me curious - one valve is ticking slightly even after new lifters. It is quieter than before, but it ticks. I tried to adjust it more - got engine running, and slowly turned the nut, but after one full revolution the ticking remained. I have no guts to turn it more at the moment. What could be cause of this? Same valve ticked much louder before too, so I guess it's not the lifter's fault.

 

You should have never put that intake on your engine!!! That is a single plane intake, which kills low end torque big time!!!! Buy a performer tbi instead or stick to the stock intake. Do you have headers? When headers leak they tend to make a ticking sound too. When you have the intake off turn the crank until the lifter is all the way to the bottom then adjust the rocker nut until the push rod does not turn than do a half turn. repeat this procedure until all valves are adjusted. All carb intakes run like crap on tbi, why did you change it? TBI is very sensitive to mods and if you do not know how to mod TBI ask around buddy an we will gladly help you out! Your cam swap is fine, slap that performer tbi and get headers, full 3 inch exhuast, and 84 camaro dual snorkal intake. Trash or sell that worthless intake to somebody with a race car.
TBI intake+headers+tune+gears=one torquey 305!!!
Torker 2 intake + L03TBI=One slow POS!!!!!!!!!!!!!!!!!

 

Come on. I know that single plane would kill SOME of torque on low revs, but my other vehicle has SP+TBI combo from it's birth and it is driveable as any other. I don't think that only intake is the one to blame. I have read of guys using Torker II and TBI and they did run fine even on street.

I got headers, that was first mod that I did years ago

And I know how to adjust valves, I did it correctly and because of that I did ask, why one valve still ticks. I know, it's valve not leaky exhaust, because I used stetoscope to check it out.

 

That's not entirely correct, but generally large runner single plane intakes do not work out very well on LT1 camed 305 - you loose bottom end. Torker Intake is a single-plane, low-rise design that can give you top-end horsepower, but low RPM torque is compromised. As for ticking sound - lozantius is correct on exhaust leak. Some headers have uneven flanges which are prone to leaks - also check your header bolts as they tend to loosen over time.

As for intake go back to stock TBI intake for now - it is not a limiting factor under 4500 RPM. Above 5000 RPM small intake ports may limit air flow. Just about any modern designed dual plane intake (2101, etc) will provide sufficient flow up to 5500 RPM. The dual plane - heated design will keep stock calibration from going nuts. The 305 torque plateau should be between 2500 and 4800 - this is where you want to shift.

//RF

 

A 305 TBI will not lose an ounce of low-end torque with a single plane, I know I have tried it. Dual planes SUCK for a TBI application. I ran a Weiand 7525 in a 305 Q-Jet application and later a Victor Jr Vortec with a 454 TBI on it. Both of them would break the tires loose in a heavy G-van with a stock torque converter and 3.08 gears and pull hills with the torque converter clutch locked in OD. Stock intake is measurably restricting it by 3,500 rpm.

 

Fast

He is in Estonia - his choices and availability of intakes is very limited. No disrespect to you OM, but let get this guy walking before he can run 100 m dash at next Olympics!

//RF

 

FYI-- I have always heard this MYTH that a single plane intake hurts low-end on a TBI engine and it is just that a MYTH. Tweak the ae and air/fuel mixture for both intakes and it will make the same low-end torque. With substantially more midrange and top-end HP.

This was the vortec head 350 in my van with an edelbrock 2116 dual plane intake and stock LT4 cam.



Same exact setup with a very mild cam upgrade and 2912 victor Jr. If I was going to lose low-end torque, don't you think I would lose it from more than 12* increased duration at .050" on both intake and exhaust as well as from the single plane. Its only a 9:1 350 BTW!

 

Thats my point exactly, shouldn't go trashing an intake that will work perfectly well with a little retweak to the chip.

 

rmx

List your engine particulars in detail.
CR ?
Headers ?
TB ?

 

Well, mods that I have done:

1. 14x3" Fram Air Hog, planning to replace with CAI in future.

2. Stock throttle body with slightly raised fuel pressure (couldn't get injectors running without few larger drops before raising fuel pressure to about 1 bar, running slightly rich after that, but not too bad)

3. Homemade 10mm TBI adapter, Edelbrock Torker II intake, port matched to heads.

4. Ported and port matched stock heads, shaved about 0.5 mm. Ramps still there and mostly intact. Intake ports finished with 40 grit paper rolls, exhaust side polished smooth. Fel-Pro OEM replacement head gaskets. Compression ratio maybe just slightly higher than stock (9.2?).

5. 1994 B-Body LT1 cam

6. 1.6 ratio Comp Cams roller tip rockers, Comp Cams 249-981-16 springs, stock sized valves, new valve job.

7. Flowtech short headers, dual Magnaflow cats, 2.5" catback (planning to change to 3")

8. Stock PROM at the moment

Does it make sense, that after cleaning old lifters, they leaked and for that reason the valves didn't open fully and my stock PROM did survive the mods?

 

Hydraulic lifters are designed to bleed off oil when lifter is ridding on the base circle of the cam lobe (valve is to closed in position ). For better - complete explanation regarding hydraulic lifter operation see:

http://holdenpaedia.oldholden.com/Hydraulic_Lifters

The ticking noise could be coming from multiple sources - it is very hard to say. With the flat tappet lifters this was usually a sign of worn cam lobe, not the case with roller lifters (with stock cam, reasonable spring pressure). Some valve train noise is to be expected with roller cam - the lobe ramps are aggressive when compared flat tappet. How loud is this noise - can you post a video??

Stock EPROM can not be altered - unless you have taken it out, removed protection label and inserted under UV light and tried to reprogram it in PROM burner. It should be just fine.

Fuel pressure of 14 PSI (1 BAR) should be OK for now.

Do you know (or have you looked into) how to burn your own EPROM chips???? Have you looked into EBL conversion??

//RF

 

The noise is not too loud, but its audible. When I listen it with stethoscope, then it is pretty strong metallic "click". I try to make a video, but I'm not too sure if my phone is any good for this, I have no video camera.

I know how to erase EPROM with UV eraser, I know how to use the programmer, but my cheap one don't write 2732 or 2764 EPROMs even it's documentation says so. So at the moment I am in the middle of finding new one. I know basically what I should check and change too and always I can ask from here.

EBL conversion is out of my budget at the moment

 

Your combo worked on your van but lets get realistic here buddy first of all you have a 350 with vortec heads with EBL flash, plus the supporting mods to reap the advantages of a single plane intake! The guy lives in Estonia and has a stock 305 with a b-body(whimpy cam) installed!
He is rocking a 305 with a mild low end to midrange torque cam on a intake that was designed for midrange and top end power. This combo is a major mismatch, and the best intake for him is a dual plane intake. The B-Body cam was designed for low to midrange torque and that intake/LT1cam combo on a 305 engine will be a SLOW PERFORMER!!!! ENOUGH SAID!!!!!! Follow my advice or continue to waste this guys time trying to make that intake work on a tame setup. Save this guy the heartaches and waste of time, or post up your setup so he can duplicate it.

 

Well, my truck has 4.3l V6 and single plain with TBI. It is slightly slow under 1800-2000 rpm but it's driveable. I don't know what are the parameters of the cam, but I guess not too "high performance oriented". So I really don't believe, that intake is only one to blame.

 

I am sure its drivable but yes you lossed low end torque. Go heads up with another firebird with the same engine and you see nothing but tail lights. On my car i ran the stock TBI intake with a LB9 off my wrecked Iroc and it pulled hard, but when i went to the edelbrock TBI the torque was way better and helped my RS dipp into the low 14 1/4 mile range. Save the torker for a built race car engine not a stock engine.

 

Forget 2732 (A) or 2764 EPROM - this ancient UV technology is better left for history books. What you need is

1) TunerPro ver 4.xx - for editing BIN files: http://www.tunerpro.net/

2) Take a look at your ECM locate a service number - You can download BIN file Definition for 1228746 ECM (or equivalent to yours): http://www.tunerpro.net/downloadBinDefs.htm

3) G2 adapter from Moates http://www.moates.net/g2-memory-adap...g-spacing.html

4) Get 2 x SST 27SF512 or 27SF256 - should be available in EU from parts distributors. Check your programmer documentation and see if can program above chips

5) Build ALDL cable. Google is your friend.

6) Get a spare 8746 ECM for your thrid gen.

7) Download WinALDL

Suggest that you read a comprehensive sticky - introduction to EPROM tuning.


Build ALDL cable (or if funds are available buy one). Install WinALDL or use RT version of TunerPRO to gather data logs of ECM parameters while engine is running.

Get spare ECM - it is like having an insurance policy! Yank out original UV EPROM. Install G2 Adapter. I also like to install ZIF socket in place of supplied DIP socket. There is less of a chance of breaking or bending chip leg.


//RF

 

Did you not notice where I said I used a Weiand 7525 under a Q-Jet on a mostly stock 305 HO and had ZERO issues with torque in a heavy G-van, just more midrange and top-end performance. The LT1 B-car cam is a hotter cam than I had in my 305.

Look up Dewey316s combination, he was doing quite well in the torque department with a Single Plane and TBI.

 

Are those RWHP and torque curves? What do estimate the drivetrain loss at?

 

Those are rear wheel hp and tq numbers. The van had a 700r4, a 9.5" corporate 14 bolt rear-end, 2 piece driveshaft with carrier bearing, and in all but the last 365 HP dyno pull, the mechanical clutch fan cooling the engine. I figure with the fan in place I was losing a solid 20-25% through the drivetrain.

 

Fast, I thought there was drivability issues with a single plane intake and TBI? Keep in mind I live in Canada and would like to drive the car all year round (hot, cold and everything inbetween). I ended going with a Preformer RPM so I could plumb coolant under the plenum as per rbob. FWIW my 350 is 10:1, 218/224 @ .050 113* and lift in the .550 range. It made just under 400 FWHP (91 octane) with a carb on the engine dyno... Would love to see your numbers at the wheels of the 1988 Caprice the engine is in.

 

Well, after so much time passed I let you know that my car is drivable again.

The worst problem cause was actually somewhat off timing marks on aftermarket damper. After setting the piston to real TDC, the timing mark on damper was about 8 degrees off.

More timing problems were caused by false detonation reading - after intake swap the air cleaner touched slightly the hood and caused some noise that knock sensor read as detonation.

I replaced the injectors lately and now need to work with fuel map to compensate the flow rate difference somewhat. But the car is drivable with some small issues