need help

 

we are going to need a lot more info, engine specs, and anything else you can give.

Larry

 

Also need what you are using for a carb, distributor and what the timing is set to?

 

Compression?
Heads?

 

Hi Larry and thanks. New to this site and all of the info didn't seem to make here. We have rebuilt a 455 into a 488 which should produce about 450 h/p with a eagle stroker 6 months ago and it is lacking torque and horse power no matter what we throw at it. The motor is fitted in 1974 Australian muscle car, a Holden Torana which weighs 3000 pounds and is street registered but not legal for that size motor. As we have limited room in the engine bay it is fitted with standard exhaust manifolds which we know is a problem but it is not all of this motors problems. After the motor was rebuilt it felt good and responsive but as we know you don't know what you have till you put it down the track. The car ran a 14.1 at 103 mph and no matter what we did EG (timing, jetting and valves settings) it still ran the same times. The standard motor use to run the same times. We were advised on assembly of the motor to advance the cam timing for more torque so this was the first thing we change back and degree the cam to the specs supplied on the card. Of to the track and once again there was no improvement in performance. We decided to change the 770 avenger carby to a 850 hp and still no improvement. After talking to the engine machinist he feels that it could need more compression but I am sick of throwing money at the motor for no result. The motor is driving a turbo 350 with a 3200 stall convertor to a ford 9" with 3.5 gears. Here is a list that is done to the motor

Eagle crank
Eagle rods 4.5 stroke
Mahle pistons 22 cc Invert dome
Deck height is .010
Static compression is 10.06
Rotating assembly is balanced
Mondello JM25-28 cam
Valve lift is Int 523, Exh 544.
Duration @ 50 is Int 234, Exh 244
New lifters
3/8 push rods
Roller rockers
Edelbrock Heads posi flowed approxamently 300 cfm?
Edelbrock torker manifold ported and posi flowed and spiral cone
Holley 770 avenger or 850 hp carbies
Hei distributor
Thanks Paul

 

What was your cam advanced to? What are you running for timing, total mechanical, initial, locked?

I know this sounds like a stupid question but I have to ask. Is your throttle opening all the way? Cause by my calculation your HP=233

What's your 60' time and where is your torque convertor flashing to?

 

I'd think that cam is too small for those inches.
Ask Cutlass EFI -

 

The cam was put through a degree machine which will give you reading in thous and this cam was straight up and down at 82 thou and I was advise to assemble about 88 thou. It came out at 90 thou which I think is 4 degrees. Yes we are getting full throttle. The distributor is locked up at 19 degrees. initial is at 10 degrees And advances to 36 degrees at 3000 rpm. The convertor starts to take up at 2200 rpm and the best 60 foot was 2.077 with no wheel spin and the 1/8 mile was 8.973. The 1/4 mile we ran14.059 at 94.85 mph

 

Rockers installed correctly and not collapsing the lifter plunger down to nothing? Back off on a rocker while it's running and see if the RPM comes up or if the rocker starts chattering. Put a dial indicator gauge on the rocker tip and verify the lift number while rotating the engine by hand.
Have you verified that timing with a 'dial back to zero' timing light or is that what someone said it should be?

 

All are good suggestions. You'll need to verify everything, everything. Does it run smoothly otherwise? Do a compression check as well just to make sure.

Has the trans been rebuilt as well? Even though it may seem to shift o.k., if it's bad it'll sap all the power out of everything. I have personally experienced a bad tranny making a huge difference in performance, twice.

Otherwise maybe a trip to a chassis dyno is in order. They can check your air/fuels as well.

And that cam isn't too big or too small. You could've gone bigger but that's not your problem. My guess is it's the tranny.

 

you moght need a bigger fuel pump.

 

The only weak link in your parts combination is the lack of headers but that isn't costing you the 200+ HP you seem to be missing. Like others have said, go through and check everything. First I would check cranking compression in all 8 cylinders. Make sure all of the plug wires are in order and firing, carb is getting wide open throttle etc. It's not a minor adjustment that's holding it back that far. That thing should be deep into the 11's

 

I've seen torque converters do this also, I had a buddy that was fighting the same issues last season.

In addition one of the other members had some issues with an improper cam install but his engine would not ever idle well.

 

Hi guys and thanks for all your great ideas but we have checked them all. The fuel pump is a electric 145 gph and we have 6 psi constant and it not starving for fuel. The compression on a cold motor is 180 to 190 in all cylinders, as the plugs are very hard to get to and I hate to burn my hands. The tranny was new from the rebuild but we also thought of the same problems so after 5 hours of work, as we have to remove the motor to remove the tranny and convertor. We had them inspected and rebuilt but no problems where found. We have checked all valve train operation and timing and that is all fine. When we set the rollers, we adjust #1 when #6 exhaust valve is fully open and then #5 exhaust valve fully open to adjust #8 and so on through the firing order with a 1/2 turn of preload on the roller. We even thought that we may of been supplied the wrong cam, EG( lifter bank angle ) but after checking its all ok. At the moment we are running the motor a bit rich but this still does not explain for its lack of performance. As for when a motor is designed it should come near to the horse power your after and you should be able to tune the rest of the h/p it should have. It has been 20 years sense I have rebuilt and played with high performance motors but the principles are still the same.

 

Have you verified TDC on the balancer?

 

Yes when the motor was assembled we checked with dial indicator to the top of the piston and found the balancer was out buy 1 degree. When we adjusted the cam back to the specs on the card we use a piston stop and the balancer had not moved.

 

When you talk about the cam in thousand's, how do you come up with that?
Did you use a degree wheel to install the cam as per cam card.
I have had two cams from Mondello/Engle cams, of which would not degree in.
I hate to say, but your problem is in the cam. I would get a custom one from CutlassEFI/Mark. I would go hyd roller. just my opinion.

Gene

 

Its similar to degreeing the cam. The cam is placed into a machine which is hooked up to a computer and rotates slowly so that it does a profile of the cam lobe. It calculates the lift of the cam at TDC and gives you a measurement in thous. You need 2 dial indicators ,1 for the piston for TDC and 1 for the lifter to see what lift you are getting and then you can move the cam to its correct position. It makes for an easy way to degree it when you are assembling the engine with the heads off and on a stand.

 

That seams all well and good for the cam. Sounds like you will get all the info you need to make sure the cam is what the cam card says.
But how did you degree the cam in the engine itself, what timing chain set did you use ? You need to degree the cam to the crank you have with the timing chain set you are using.
If you are using a cheapo timing set, I have seen them as far as 10* retarded or even 10* advanced and every degree in between. I had a cam one time, that was run on a cam machine and was good, but in the engine would not come close to what the cam card said, best i could figure the cam gear pin was off.
How did you degree the cam in the engine?
Gene

 

When I changed the cam back to the spec card I used a degree wheel

 

did you degree it off the #1 cyl intake lobe.
Did you advance the cam ? Or install as per cam card.
Did you have the same problem with the other cam?

Gene

 

Originally the mondello cam was advanced but when I reinstalled it, it was to the cam card specs with a degree wheel. When we installed the other cam it was installed to the card specs with a degree wheel and still no improvement. Using the thou method it is similar to say (.050 at 234 duration). Place #1 dial indicator on the lifter and find the heel of the cam and zero it. Rotating the bottom end till # 1 piston is at TDC by #2 dial indicator and see how much lift you have. In this case it was to be 82 thou. If it is not correct you adjust it using the bottom sprocket.

 

Your cranking compression would tell me that your cam timing is probably correct but people make this harder than it needs to be.

Here's a simple formula;

234@.050, divide by two, that's 117.
Say you want to install it on a 108 intake centerline. Then just take 108 from 117, that's 9btdc. That's what you should see on your degree wheel at .050 tappet lift.

 

Thanks very much cutlassefi for explaining that and a quite easy way to work out. I will have to remember that way myself. The cam was degree in and the motor runs fine and sound great, but has any one given any thought to the compression. Do we need more to get it to perform.

Paul

 

Was the block milled to obtain a certain piston height?
Olds blocks can leave the piston as much as .020 'in the hole'!
Which pistons are you using? How deep are the pistons dished?
Have the heads been milled?
What head gasket?
What cam overlap?
All pertains to compression.

 

Most of the info at the start of the thread except for the gasket thickness which is .040"and no the heads have not been milled.

Paul

 

I would believe lifters are hyd Steve based on them giving a 1/2 turn preload in prior posts so I don't think his adjustment is off.

 

Any chance 14-seconds is limited by the gear ratio?
Steve

 

Just dawned on me - what size fuel line is from the tank to the pump??
Hoping that's the problem - I know a BBC will choke on SBC original lines!!

 

The fuel is 1/2" from the tank to the carby but it is not starving for fuel. The distributor is from mondellos which came in a white box?. The cam is a hydraulic with a 1/2 turn of preload on the rocker. I had my machinist go through and check them as well and there adjusted spot on. The internals of the distributor are lock up at 19 degrees which should suit the cam so I was told ? but you could be right by giving it a bit more of advance and see what happens. I have been a bit shy on giving more timing as this thing can run a little hot on occasions. Won't be able to take it to the track for a couple of weeks as the willowbank track where we go is hosting the winter nationals (Australia's grand finial for drag racing) but I will try and give it a go on a lonely piece of road. Cutlassefi suggested a chassis dyno and maybe that's where it may need go but its just I am not a big fan of them. Any thoughts about the compression.

Thanks Paul

 

Just went and ran the motor and it is advancing the timing. The problem is that my timing light has just stopped working as we started to rev it so I can not tell you to where it would of been at 3000 rpm. Had a quick look at the internals of the distributor and could not find anything loose or broken so I will buy a new timing light tomorrow and also talk to the person who set the distributor up and will post the outcome tomorrow.
Thanks Paul

 

Since you're only running manifolds, not headers, is there a way to find some 'extrude honed' manifolds?
Or some 'block huggers"?
What's after the manifolds??
Since it runs the same as the old motor, it's gotta be the same restriction!
Headers are worth 20-30% on a stock motor, and must be more on a stroker - no way to get custom headers made??

 

Steve, you might be on to something, I was looking at his total of 36 @ 3000, with an initial of 10. I did the math but assumed the initial was set for ease of starting due to higher compression. Generally I don't care where the initial winds up.

 

Its runs standard manifolds and dropping in to 2 1/2" exhaust system. Headers would be great but we are restricted in room as there is steering shafts and components, chassis rails turning in towards the motor with only about 3" in diameter to bring the headers through. The 2 1/2" exhaust just makes it through. In Australia oldsmoble performance parts are not in great demand and it is hard to find what you need and we have to import it from America. If you blokes know of a better style of performance manifold and where to get it from any suggestions would be great. I know that this is some of the problem but I don't think that is all of it.

Thanks Paul

 

So on a 300hp stocker they're worth as much as 90hp? I don't think so.

BTR did an iron headed 496 for someone a year or two ago. He posted the results with headers and with manifolds, it made a 40hp/50lbft difference. That's not your problem.
http://highperformanceolds.com/phpbb...o+build#p28970

Verify your timing as mentioned and try to find a chassis dyno with a wideband, it could also be going dead fat up top as well. That'll give you more verification and go from there.

 

I agree lack of headers are not causing this problem. However I am curious to what is?

 

Have you found TDC on #1 and does the balancer "O" mark lines up with the pointer?

Also we would like pic's of the car.
Also is there room for wheel well headers?

Gene

I just read through again and see the balencer was good,
maybe double check

 

Well guys checked the timing last night and it was at a total of 28 degrees so bumped it up to 34 degrees total and we will see where we go from here. Its raining at the moment and forecasts don't look good for about a week, so when we get a dry bit of road we will see if that has helped and I will let all of you know straight away. I don't know if it is possible if the old timing light could of been reading wrong or what, but thanks for pushing me to verify everything.

Paul

 

[QUOTE=64Rocket;
Also is there room for wheel well headers?

Gene
[/QUOTE]

It ain't the exhaust manifolds. I think we've beat that horse to death.

 

Paul,
We like pic's of the car.
Does your track have a weekly program to drag race. Is there classes for different type cars and the times they run?

Gene