I have a 1970 Cutlass Convertible 442 Clone with a transplanted 455. The past owner tells me the engine was built by an engine building company and has a little bigger cam than stock with small valve 'E' heads. (It has a nice lope to it) It has an Eldebrock intake with a 4bbl and long tube headers with a full 2 1/2 inch exhaust (flowmasters and crossover pipe). The trans is a TH400 followed by a 3:23 rear posi gear. I'm not sure of the tire height. I would think this combination would give me plenty of performance. I've had high performance cars in the past (manual trans only) so I know what a really fast car is. My last car would run mid 12's in the 1/4 at 118 mph on street tires. My clone drives like it has a lumbering big block with maybe 300 hp. While it has a posi rear, there is no way the engine will spin the tires. What am I missing here? The car is a dog. Any suggestions other than swapping out the heads for the Edlebrock aluminum heads and a bigger cam? I can't believe I don't have better performance. Is this typical with a heavy convertible? Perhaps I have my expectations set wrong. Thanks for any help you can provide.

 

Check the obvious first. Is the timing correct? Is the carb working correctly? It might be a low compression later model 455. 71 and later were low compression engines and if it was built to the low compression spec's that might be the problem.

 

Sounds like they may have installed a low compression engine. May have too big a cam for the low compression you have. The cam may have been installed wrong, not up to the spec sheet for the cam. Timing may be way off. Carb not opening all the way. What carb is there?
Small valve "E" heads are great for the street. May even have very restrictive mufflers.
For the most part, I think you have a low compression engine of which they installed "fel-pro" blue thick head gaskets of which makes it even lower compression.

Gene

 

Thanks for the suggestions guys. The block is definitely a 1970 455 according to the numbers on the front by the Oil fill tube. THe carb is a Holly vacuum secondary with an electric choke. I'll check the timing, see what CFM carb I have and make sure it's opening all the way. I hope that is the problem beause those are easy fixes. Thanks again.

 

Low compression engine? My '71 Olds 98, a low compression 455, spins the tires like crazy, from a complete stop or a very slow roll, and the carb hasn't been touched after the car sat f/ 10 years, all original w/ 93,330 miles. The 98 weighs 4700 lbs on the registration. There is something "WRONG" with your engine. Is it running on all the cylinders? Yes, check compression, vacuum, and so on. Read the plugs to see what the heck is going on w/ that engine.
Hard to believe that a 455, w/ headers, a cam, an aluminum intake w/ a 4 bbl. won't turn the tires. I say there's something wrong w/ the engine.
Yes, check the carb, but check the vital signs; compression and vacuum, and read the plugs. If there's something really wrong, it'll show up. Are the secondaries opening? Running on the primaries would do it.

 

Timing!!!!! I bet thats the problem. Bring it over on a nice day and ill tinker on it with you! Looks like its gonna be nice for the next week, I was thinking of taking my olds out for a spin Im in North Aurora,il

 

Are you sure it's a 3.23 rear? My buddy just bought a 78 T/A with an Olds 455, Performer, Headers, Small Cam and Edelbrock heads. Wouldn't spin the tires come hell or high water. Found out it had a 2.56 not the 3.08 he thought it had. Check that as well as everything else everyone has mentioned here and let us know what you find.

 

Even with a peg leg rear end and 2.56s a BBO should roast at least one tire. Oldsguy had a 1969 Delta 88 with a stock 455 and 3.08 peg leg rear end and it would roast one tire all day long.

Definitely check your timing and carburetor. Buying Edelbrock heads and throwing them on would be a waste of money unless you just have a desire for aluminum heads.

 

Thanks to everyone. The next couple of weekends are completely booked so I'm not sure when I will find time to check everything. I will also eventually check the rear end but the seller gave me the number of his mechanic who installedd the 'O' type rear end and the mechanic confirmed it was a 3.23. I've never had an Olds 455 before so I don't know what to expect. This has all been very helpful and I will definitely post my findings and results of changes.

 

The oil fill tube is easily changed (and frankly should have been removed when the block was re-machined and cleaned for rebuilding), so that doesn't prove anything. Check the VIN derivative stamping on the block. Of course, it the engine has been rebuilt, it really doesn't matter what block they started with.

Are you sure your secondaries are opening? Verified the choke is fully open?

 

Hey Bob

Just give me a call sometime ill stop by and see if we could figure it out.


Josh

 

It should be a mid 13 to mid 14 second car and close to 100 miles per hour in the 1/4 mile. I've seen open plenum intakes like the Olds torker really hurt the low end torque.

 

Since it has a little bigger than stock cam, it might need degreeing.

 

"The oil fill tube is easily changed (and frankly should have been removed when the block was re-machined and cleaned for rebuilding)"

Funny thing, Mike (the guy who owns the shop) actually likes to leave them in. Says it makes a great "handle" for handling the block.

 

A 323 gear and a cam with a nice lope to it could be the problem, you may need a higher stall torque converter and a lower gear out back. Try and find out exactly what RPM range the cam is for.

 

I always screw them up if I leave them in.

Of course, I also screw them up when I take them out...

 

I had a 2.56 posi behind a very mild 455 and I couldn't keep tires on that car. 300' burnouts were the norm in that thing.
Check the timing. If you have an HEI start at 18° BTDC and take it from there.

 

I suppose the ideas that the cam needs degreeing and that it's the wrong one, and probably the timing, etc. is great. I'm thinking that the guy should just check the vital signs first. After my "tripping out" when I read, "must be a low compression engine" and "I bet it's the timing," like someone should come to that conclusion, and gave my old boat as an example, I came back to my senses and asked if the secondaries were opening. No knocking intended, but what happened to "FIRST THINGS FIRST?" Checking to see if the engine is sound, if the compression is good and even across the board, checking the vacuum, and reading the plugs. These three things will give you a good starting point, before you go checking/changing any settings, ie; timing. A car like the one this guy describes should turn the heck out of the tire(s) reguardless of the rear end. Don't need to be around/have experience w/ Oldsmobiles to know that one. W/ the guy sounding new, give him some starting points that won't have him thinking that the engine builder installed the wrong components or set internals up incorrectly. Give him some path that won't cost him any money and that'll help him find his problem, at the same time giving him info about the condition of the engine in the car that he just spent his hard earned cash on. Don't mean to sound shitty, but what I read made me think that conclusions were being jumped to just by what was posted, conclusions that would take hands-on testing and checking, and much more than reading afew sentences. First things first.

 

X2 Plus check the timing like everyone has said.

 

Hey guys. I am new to this site and new to Oldsmobile 455's. I haven't owned a cutlass since buying one new in 1972 with a 350 Cu.In. As far as big blocks go, I've been running with the Chevy crowd for 18 years but now I'm back and happy about it. And thank you for suggesting I start with things that don't require tearing down the motor. The guy I bought the car from can't find a cam spec sheet or a manufacturer or number. He bought the engine already completed from what he says and had someone else drop it in. I will start with a compression check, plug check and make sure all 4 bbls are opening. . It will be easy to check the timeing if the engine was assembled correctly. It only has about 8000 miles on the rebuild and they are not hard miles as far as I can tell. I can also jack up the rear and see how many revolutions the driveshaft turns with one turn of the wheel. That will give me some idea of the rear gear without having to take it apart. I'll post the results when I get them. I hope you guys aren't mad at each other and thanks again for helping out. By the way, it does have a 6AL MSD ignition and distrtibutor and fires right up, revs fast and idles well. Obviously that doesn't mean everything is hunky dory.

 

ARE YOU KIDDING???????? We're super pissed at each other and it's all your fault!!! Just kidding, good topic. I feel that the topic shows different people and their first reactions to reading about a problem they can't physically put their hands on. It was good. Thanks.

 

OK. I did the preliminaries and here is what I found. The rear gear is definitely a 3.23:1 and the tire height is 27". What is odd to me is that the timing seems to be stuck. The timing mark on the balancer is about an inch (at least) beyond the end of the fixed timing tab so I can't tell what the initial timing is. When I reved it, the timeing mark didn't move. I took the distributor cap off and discovered the whole thing is coroded and rusting inside. The car must have sat a lot. The cap terminals were coated with green corrosion and one of the springs that determine the timing advance (no vacuum port - electronic) was rusted. The mechanism seemed to be working properly but I think I need to pull it and have it serviced. The Holley has all 4 barrrels opening correctly. I have two more questions for you. I couldn't see the bolt that holds the distributor in place becasue the distributor sits to low on the back of the engine. To save me from mounting the engine to look over the back, does anyone have a tip on how to get a distributor wrench on it without climbing on it? Also in a drawing of where the number one cylinder is on the distributor along with all the rest in firing order sequence, the number one cylinder is shown on the back towards the firewall. My number one cylinder is on the front facing the carb. Is is installed 180 degrees out of sync? It seems to run OK or doesn't this matter? Thanks everyone. By the way, all the plugs were exactly alike. They are not fouled and are all black indicating a rich setting. I haven't done a compression check yet.

 

If the internals on the distributor are corroded and nasty then you should definitely clean and service it. The easiest thing to do would be to buy a new set of points from the auto parts store. They are about $8.00 and install with a few machine screws.

A GM distributor wrench should fit easily on the distributor hold down bolt. Sometimes it is easier to fit it on from the driver's side of the car. Put it on before you start the car so you aren't dodging the fan and alternator. Then once you start the car you can just reach back and loosen the distributor.

 

W/ all you've been doing, I'm sure you can remove the distributor and clean it up. Just becareful to remove everything carefully and reinstall all the components in the exact order/placement they came out. It's just a matter of cleaning it up completely. In the future, the use of a vacuum gauge will tell you more than any other single check you can do, atleast on the pre-computer aged cars. Sounds like the engine will only take some basic maint. to get it running well again. ...and beable to burn the heck out of the tires. Good Luck. I'm looking foreward to seeing a picture of a big "burn-out."

 

A stuck mechanical advance will certainly add to a performance problem. Just before you pull out the distributor, CARFULLY mark the firewall or the back of the intake manifold with chalk or a piece of tape exactly where the rotor is pointing and drop it back in the same spot, it'll fire right up.

 

I have a good Points distibutor we could try that out. If your not getting advance, then thats your problem. Fix the distibutor and you problem will be fixed.

 

Wow, you guys are hooked on this site. Thanks for the quick response. This is certainly more fun than working...

I guess the next test should be the vacuum and then I'll pull the distributor for servicing. What should the difference be between manifold vacuum and carb vacuum? Thanks for the tips.

 

You know that the distributor is a problem area, so pull that and clean it up first, and then after you get it back in, check the vacuum and inturn the vitals of the engine. You're on your way f/ sure.

 

Manifold vacuum should read maximum at idle with the throttle plates closed. You will have 0 ported vacuum at idle. Ported vacuum increases as the throttle opens. Vacuum advance should go to ported vacuum.

 

Use the "full vac. port" (from manifold) to check vital signs. If you're not familiar w/ a vacuum gauge, use the booklet that comes w/ the gauge. It'll give you a laundry list of what you can check, and even set, and how to do it.

 

Here are the latest test results. I took the distributior apart and cleaned it up, changed the springs and put the correct bushing in it and it seems to be working correctly. The initial advance is at 16 with a total of 37.
On to the compression check. The engine was warmed up, all the plugs were removed and the carb butterflies were held open. Here are the readings.
Cyl. 1 160
Cyl. 2 162
Cyl. 3 155
Cyl. 4 152
Cyl. 5 155
Cyl. 6 155
Cyl. 7 153
Cyl. 8 149.

Can anyone comment on what this indicates? I read somewhere the compression should be around 180. I put all new plugs in it last week and only ran it long enough to set the timing and do the compression check. The plugs are already black. So really rich. I can't find any numbers on the Holley that correspond to any on their web site. It has no tag on it. I'm thinking a 650 would be plenty for this engine with the "E" heads. If I adjust the idle mixture scews to the highest manifold vacuum and jet it down a couple of sizes for starters, am I going in the right direction? Is there anyway to tell the cfm of a Holley when you can't find any numbers? Or maybe I'm not looking in the right place. By the way, how do I post a picture on this thread? I'd like to show you an electrical connection close to the throttle lever and it makes contact with the throttle lever when it is at WOT only. I've never seen one of these before. I'd like to post a picture of the carb. Thanks for all your help.

My next test next weekend will be the vacuum test.

 

The compression test numbers show it's got less than 15% difference between the cylinders so that's good. Since we don't know what cam shaft it has or the actual compression ratio we can't rely on them for too much more but since you said it has a healthy lope the cam is probably a few steps over stock. The engine probably has under 10-1 compression but that's just my guess. What's the vacuum reading at idle?

The Holley should have a number at the front of the air horn stamped in and should say something like "3310-1" or 4780" or something like that. Find that and we can tell you what it is. The switch you say is contacting the throttle is probably a kick down switch for the turbo 400. Since the car is a clone it wouldn't have a factory kick down switch at the top of the gas pedal so someone either bought an aftermarket one or got an older model from the junkyard or something.

Have you repaired the distributor and taken it for a spin yet? I'll bet it's a lot peppier than it was before.

 

dry then wet (w/ a squirt of oil).

 

THanks 44T. I'm am down with a sinus infection and barely was able to watch the big game yesterday. I plan on hooking up a vacuum gauge sometime this week and I'll post it then. Thanks for your comments and for identifying what the electrical connection is. That sounds right.
Regarding the distributor, I havn't taken it for a spin yet and tonight we are supposed to get 2 -12 inches of the white stuff. I won't take it out in bad weather. About all I can comment is that it starts right up but isnt' quite as quick on revving as before. I do feel safer with it being set correctly.

 

Rest up, it'll be there when you're well. I have strep throat myself right now. Winter sucks.

 

Hello again. I have discovered a new problem. First of all, here are the stats given my latest efforts installing new plugs, checking all the vacuum hoses (AOK), making sure the rear barrels on the Holley Avenger 770 are opening, checking the squirters, cleaning up the distributor and testing the advance while in the car, setting the timing to 16 at idle (750 rpm) maxing out at 37 degrees. I've checked the fuel pressure and it is slightly over 6 psi and holds steady. The vacuum is 13 hg at 750 rpm idle and maxes at 22 hg at 2000 rpm which equates to abour 45 mpg. You may remember the engine is a 455 with long tube headers. The new plugs all look the same and the compression check showed all cylinders within a 15% variance. By the way, it really gets up and goes now (TH400) with all I've done but still can't spin the rubber.
Here is my newly discovered problem that I could use some help with. After the engine warms up to 185 degrees and the oil is holding between 25 and 30 lbs of pressure everything seems to be great. Then if I turn it off using the key, it won't crank normally and definitely won't start until is has cooled down for about an hour. Then it starts effortlessly. If I try to start it before it cools down, it cranks exactly like the timing is too far advanced. It pops and spits through the carb and cranks with great difficulty (erratic) and it will not start at all. I don't know if the engine heat is boiling the gas, if I have vapor lock or if the starter (aftermarket reduced size) is too hot. It may be suffering from multiple problems. I can't figure out the popping through the carb. I've double checked the timing once I can get it started and it is perfect. I am fighting a lot of frustration. Thank God it's winter in Chicago and I don't have the itch to drive it. I will have to crawl under the car and see how close the starter is to the headers and perhaps install a heat shield just to eliminate that potential cause. The guy I bought the car from didn't have any receipts so I can't tell when things were replaced. He says he didn't drive it hardly at all over the past 3 years - just enough to keep it lubricated. As an exmple, the Holley has 3270 stamped on the choke horn. Does that mean it is a 1970 vintage? The aftermarket starter looks new from the outside but with no receipts, who knows?

 

Your starting problem is common with headers on an Olds.....you can try a heat shield and make sure starter is a high torque and has a HD solenoid. There is a solenoid relocation kit available too. Was it ever established what cam specs are and your rear gears? Timing is a little advanced for street and crap gas.

 

Thanks. I will start with the starter and see if that cures it. I did verify I have a 323 posi rear end. The TH400 is tight. I can't detect any slippage even when pushing it through the gears. I will not be able to get cam specs but with all that vacuum, I can't imagine it being very radical. I'm guessing it is pretty much a stock profile. When it warms up outside, I plan to pull the value covers just out of curiosity to see if it has stock stamped rockers or rollers. I don't have a clue about the starter but I will get the make and model next weekend and track down the specs. I am running premium gas (93 octane with 10% ethanol) and have MSD ignition (6AL), coil and distributor. What is your recommedation for timing? As you know, I can adjust the maximum advance, when it comes in and how fast. I am currently running a light siilver spring with a light blue spring and a blue bushing which allows 21 degrees of advance. MSD shows this set up as having all the timing in at 3000 rpm. With the timing set this way, I am experiencing a slight bog right off idle which wasn't the case when the timing was stuck way above 16 degrees off idle. The accelerator pump is adjusted correctly (no play) and moves at the slightest touch of the throttle. I am thinking about putting in the black bushing limiting advance to 18 degrees and moving the base timing to 18 degrees. Any thoughts on this?

 

If any of you are still reading this thread, I finally took the power steering bracket off so I could read the number stamped on the block pad just in front of the # one cylinder. I still can't read the entire number but the digit preceeding the letter in the3rd position is a '1'. I think the first number is a 3 and the letter is a Z. I believe the Z means it was produced in Fremont, CA. So it appears I have a 1971 455 built in California. Could this be part of the reason I don't have all that torque and power all of you seem to have? Do any of you know any of the factory specs of a 1971 block? It has E heads on it. There are no emission parts on the engine. The intake manifold is an aluminum Edlebrock (aftermarket). What I'm asking is "Are there any differences in the block if it was built to the emission standards of California in 1971?" If I rebuild it, is there any reason (other than money) that it can't be re-built with the performance of a W30 engine? Thanks again for your help.

 

If you go to 442.com, there is a ton of historical and technical information pertaining to Olds, including all of the SN and date code info, engine variations, all that kind of good stuff. Take a look and you should probably be able to find out about your blocks history and what it specs out at. Also thought I could share my recent issues with my 1972 455 because I had a lot of the same problems with mine like you are describing. It happened after I put on a rebuilt q-Jet. I started screwing around with the timing and idle mixture sYcrews, and it got to the point where it was really bogging down and it wouldn't start until it cooled down. Turned out that I turned the timing and idle speed up too high to compensate for my mixture being off. Once I fixed the mixture, lowered the timing to about 10 BTDC, and corrected the idle speed, no more heat soak and no more bogging. I have a virtually stock 455, high cruising gears in the rear and I can still smoke the fat drag radials that were on this when I bought it ( I am going to be getting rid of these 50's and the standard front tires, all mounted on some Centerline auto drags if anyone wants to trade for some SS's....PLEASE!!)