Dodgy Camshaft?

[Zedman]

 

 I thought I'd share this....

My 1981 Avanti II had stood sheltered but unused for 17+ years before I got it in 2015 and only started once by me as the happy new owner. It's been under Frames-swap since then. It was a supposedly a genuine 65k Miles old car and is in spectacularly good condition inside. Originally, I figured to leave the engine alone, but ought to at least change the nylon timing gear and investigate the issue of 'soft cams'. The fact that it had 'Anti-Foulers' on nos. 2, 7 & 8 sparkplugs made me leery.  Well, the engine is being stripped despite "when do you stop mucking around with stuff" self talk.  Lo and behold the condition of some of these Lifters.... and I haven't got the Camshaft out yet!...😬

Just 

 

[wildfelr]

RQB3263/81/305  ..WELL IVE BEEN THERE DONE THAT...10 YRS AGO I DID THE TOP (VALVE JOB)  AND REPLACED TO CAM ETC.  DOUBLE ROLLER TIMING CHAIN, WATER PUMP ETC... IF I REMEMBER RIGHT  ALL THE SBC USE THE SAME CAM...I PURCHASED A CRANE TORQUE/RV CAM AND LIFTER/VALVE SPRING SET... I HIGHLY RECOMMEND THE RV/TORQUE GRIND REGARDLESS OF MFG... I ALSO USE SHELL ROTELLA T4 SEMI SYN OIL WITH ZDDP ADDITIVE (10 YRS DOING FINE)  ..RECENTLY REPLACED INTAKE MANIFOLD WITH EDELBROCK AND ALSO HOLLY 550 CFM CARB I THINK OR MAYBE ITS A 600 I DONT REMEMBER.... BE ADVISED HOOD CLEARANCE COULD BE A PROBLEM AS MY CARB/ MANIFOLD IS TALLER THAN STOCK AND PURCHASED FROM SUMMIT..... ALSO HAD MIKE MYERS INSTALL TRUE ALL STAINLESS DUEL  EXHAUST.....ALL THIS TOGETHER MADE A HUGE IMPROVMENT IN AN ANEMIC 305... BEST WISHES ....BILL IN FLORIDA

[Zedman]

Hey Wildfelr- I wont be flogging the Avanti in any way when it's done and it has a very low Rear Axle ratio. That RV/Towing Cam is a good pick, then? As a matter of fact I'm keeping my eye out for an original GM manifold without the EGR valve flange (not a repro), a non-ECU controlled Rochester carb and an aftermarket HEI Distributor. Wanna see if I can convincingly ditch all the Smog controls and AIR pump and make it look OEM.

[wildfelr]

RQB3263/81/305....YES 3263 NEVER SEES 75MPH AND CRUISES AT 65 AT 1750RPM WITH 700R4 OVERDRIVE....THAT TORQUE/RV CAM IS FOR LOW SPEED CRUISING....PERFECT FOR US....WITH MY 2:72 REAR GEAR AND OD TRANS...I CANT THINK OF A BETTER COMBINATION.... AS FAR AS THE MANIFOLD I GAVE ONE AWAY WITH THE NON ELECRTIC Q-JET....THE Q-JET WELL PLUGS LEAK AND CAUSE SLOW STARTING.....THERE IS ALSO A KIT TO BLOCK THE EGR VALVE  I GAVE  THAT AWAY ALSO.... SO THAT IS WHAT I THINK OF THOES TWO ITEMS ....3263 NOW HAS AN HEI DIST AND IS COMPLETELY DE POLUTED.... NO INSPECTION IN FLORIDA.... IT ALL ADDS UP TO  PROFORMANCE AND FUEL ECONOMY GAINS.... WILDFELR IN FLORIDA

[John D]

sorry to hear. my 79 350 seems good, and when I changed the rear seal I noted it is .010 under so it's been freshened. But If I ever go into it I think I'd have to upgrade to roller lifters. 

[Zedman]

Been looking briefly at rollers but because all the springs need to be higher rates and I'm only looking for a vanilla Cam profile I decided against the expense. Found two 'CompCams' kits that durations  bode well & with reasonable cost (in Australia, that is 🙃) that comes with Cam, Cogs, Chain Springs,- the lot so will probably pick the one that is closes to original Chebby Spec.

I got the Right hand Head off today and found bores virtually ridgeless so a hone and re-ring might suffice...  A boil-out of block and heads plus new bearings and hope to heck the crank is not scored.

[wildfelr]

RQB3263/81/305 ...THERE IS NO NEED FOR ROLLER LIFTER IN A SBC  CRUISER/DAILY DRIVER ... YOU CANT MAKE A SILK PURSE OUT OF A SOWS EAR .... 

BUT THATS JUST MY OPINION.... BILL IN FLORIDA

[ronmanfredi]

On 9/15/2023 at 7:37 AM, Zedman said:

 

 I thought I'd share this....

My 1981 Avanti II had stood sheltered but unused for 17+ years before I got it in 2015 and only started once by me as the happy new owner. It's been under Frames-swap since then. It was a supposedly a genuine 65k Miles old car and is in spectacularly good condition inside. Originally, I figured to leave the engine alone, but ought to at least change the nylon timing gear and investigate the issue of 'soft cams'. The fact that it had 'Anti-Foulers' on nos. 2, 7 & 8 sparkplugs made me leery.  Well, the engine is being stripped despite "when do you stop mucking around with stuff" self talk.  Lo and behold the condition of some of these Lifters.... and I haven't got the Camshaft out yet!...😬

 

Here are a couple of thoughts on your engine.  If you have a 4 speed auto (200r4 or 700r4) you will lose your lock up convertor if you replace your ccc carb/distributor combo.  I've read where you can install a toggle switch to turn on the lock up converter though.  I didn't like that idea on my 82 305 (99k miles), so I rebuilt the carb completely using parts from Quadrajet Power company, replaced the O2 sensor and everything works correctly.  I did replace both electronic solenoids in the carb as well.  The EGR and smog pump can easily be removed, manifolds plugged up.  I also kept the carbon canister and valve assembly to keep that working too.

Spark plug anti foulers makes me wonder if the engine had piston ring problems.  You know you need a cam and lifters and I'm guessing the oil pan and rear main seal is leaking some like mine was.  If so, then it would make sense to do an in frame overhaul replacing the rings and bearings (as long as the crank looks good).  I replaced the timing chain on mine, front seal, oil pan gasket and rear main seal to eliminate all oil leaks.  You can remove the oil pan in the car by removing the bell crank (mounted to the cross member from the bottom) and moving the arm assembly off to the side. (requires disconnecting the tie rod ends and hydraulic cylinder from the steering arm).  Once the pan is off, you can check the bearing condition decide what to do.  Edelbrock makes a matching torque cam for it's non EGR 2101 intake.  I didn't do the cam, but did add the intake since the stock one was leaking water around the cylinder head due to extreme corrosion.  The manifold is 1/2" taller than stock, and the lowest profile that they offer, so I had to make changes to the air cleaner since it was touching the hood just a little.

Hope this helps.

 

[Zedman]

I removed the engine ages ago and am dismantling it for inspection and go from there. I'm likely to overhaul the TH350 trans (nope, no OD) as well. Gotta find/make a suitable puller for the Harmonic Balancer....

[ronmanfredi]

4 hours ago, Zedman said:

I removed the engine ages ago and am dismantling it for inspection and go from there. I'm likely to overhaul the TH350 trans (nope, no OD) as well. Gotta find/make a suitable puller for the Harmonic Balancer....

Check Oreilly Auto Parts for the puller that you can rent.

 

[Zedman]

On 9/18/2023 at 1:16 AM, ronmanfredi said:

Check Oreilly Auto Parts for the puller that you can rent.

 

I'm in Australia, Mate- 🙃 (antipodean smiley) O'Reilly's isn't part of our landscape. I'm going to collect one right now one cos I'm getting jack of making everything. You would never know if there were any leaks on this car because my import freighter  steam cleaned it to death before shipping across the ditch. I'm replacing and reconditioning everything that has oil or grease on this Avanti anyway.

[Zedman]

Finally got the Camshaft out. A quick look at it revealed about four Cam lobes worn down severely- It's junk. After looking at the number of ruined Lifters, I wonder why more lobes aren't worn. Looking at my options for a replacement and leaning to very 'stock' conservative grinds. The Nylon sprocket and chain will be replaced too.

[wildfelr]

RQB3263/81/305  ... A MILD UP GRADE TO AN RV CAM PROB NOT AN MORE $$ AND YOU WILL APPRECIATE THE PROFORMANCE IMPROVMENT....FOR ALL PRACTICAL PURPOSES CAMS AND LIFTERS ARE PRETTY CHEAP.... I PERSONALLY SEE NO REASON TO GO BACK STOCK WHEN THERE IS SOOOO MUCH ROOM FOR IMPROVMENT IN A 305 ...... WELL THATS MY OPINION AFTER 60+ YEARS OF DOING THIS $#&?%@.......1961....BEST WISHES  BILL IN FLORIDA

[ronmanfredi]

20 hours ago, Zedman said:

I'm in Australia, Mate- 🙃 (antipodean smiley) O'Reilly's isn't part of our landscape. I'm going to collect one right now one cos I'm getting jack of making everything. You would never know if there were any leaks on this car because my import freighter  steam cleaned it to death before shipping across the ditch. I'm replacing and reconditioning everything that has oil or grease on this Avanti anyway.

My bad,  I didn't look at your location.  For a cam, I would recommend:

"Edelbrock Performer-Plus Camshaft #2102 is designed for 265-400 Chevy V8 engines from 1957-86 and produce optimum torque from the low-end to the mid-range. Performer-Plus camshafts should be matched with Performer manifolds for vehicles operating from off-idle to 5500 rpm. The Performer-Plus #2102 is a smooth idling cam for daily drivers, trucks, vans, RVs and 4x4s. You can expect a major improvement in throttle response and torque." 

My cam was good so I didn't change it but I did go with the 2101 intake manifold that goes with this cam. The 2101 intake is 1/2" taller than stock which required me to get a different air cleaner top and shorter filter.  The intake did make a difference in performance by itself. 

[Gunslinger]

Not knocking the Edelbrock camshafts in any way...much to offer as they're designed to work their own products....but you might look into Lunati Voodoo asymmetric camshafts...a bit on the pricey side but offer a great deal of power without the rough idles associated with higher lift cam profiles.