I just bought a '71 Chevelle. I discovered that the engine was a "TC" series (it was in a 1980's 3/4 ton truck). The previous owner put a "Demon 750" Carb., an ELderbrock "Preformer intake" and an MSD distributor, and Hooker Headers with 3" dual / flows masters with Cross over pipe. My question is this; The TC code 454 was rated at a lowly 230 HP. What would you guess that the HP is since these upgrades? I really appreciate your help. Did I get a raw deal on this car???
Thank you

Did he replace the cam and valve springs; if so, with what grind? Take off the Valve covers and note the Head Casting #'s type of Rockers Retainers and springs - perhaps over sized Valves.

If it has something like 049 or 781 Heads with something like 8 to 8.5:1 Static compression and say a 266 or 268H-10 grind your looking at around 390+Hp at 5500rpm with tons of torque. If the Valve train is stock DON'T rev it above 5200 or you will pop the rockers break Studs and springs; other words, short shift as fast as you can - FUN Engine ;o)

If its got some where around a 9.5 compression with say a 278H-10 cam and Roller Rockers and fresh Dual Coil Springs to push it past 6000rpm then your looking at around 425+HP

Everything just a guess unless you know whats in the engine ;o)

that motor could be anything from a stocker with 200,000 miles on it to a relatively fresh rebuild with a forged rotating assembly and a good valvetrain.
the only way to know for sure is to tear it down and see what you've got.

Thanks guys!!!

Y'know---I never gave much thought to the HP ratings of these motors.

I have a fairly stock 79 454 in my garage that just runs like a raped ape. (MIGHT eventually find it's way into my 66 Elky)
In my 79 C-10 a 75 truck 454 resides and it is completely bone stock with the exception of an Edelbrockk Q-jet. (and has never been opened or rebuilt)

This motor does what it is supposed to do-----keep rolling at 65mph+ despite trailer loads or grades----Does this very well in fact.

with the 3.08 rear, gets decent fuel mileage too (better than my 59 Elky with an OD).

that ol' 454 should have lots of potential, and should push your Chevelle around just fine.
May not have a crapload of HP, but it sure makes up for that loss in torque. And torque is what you need to get going in the first place.

Then, there is the 454HO in the 59 Elky, Fun, Hi-Spirited, THIRSTY, supposed 425HP engine. It will bee a while before I can fully torture this car. I am still using a stock rear and the tiny little 2-piece drive shaft. One day down the road I will finally get this upgraded and really start slamming that car around.

Plenty of burnout power,, so I wouldnt worry about it ,, unless yer drag racing 1/4 mile...It should still be impressive stop lit hammerin in town.....

Did I get a raw deal on this car???

You got a '71 Chevelle with a 454, how can that be a raw deal?:thumbsup:

Don't even worry about the factory HP rating that can be changed in many ways, and it sounds like your engine has been changed with all the upgrades. As has been said, it's tough to tell exactly where you're at without knowing the internals and some other stuff.

For starters get us a head casting number, and get the enigine to TDC, pull out the #1 spark plug, and then run an unsharpened pencil across the top of the piston. This will be able to at least get a ballpark compression number.

Welcome to TC.:beers:

get the enigine to TDC, pull out the #1 spark plug, and then run an unsharpened pencil across the top of the piston. This will be able to at least get a ballpark compression number.

Welcome to TC.:beers:

ROFL l:)

Jeff ,what's the whole 'engine id number' ?
http://i531.photobucket.com/albums/dd358/sfatzo/EngineID.jpg?t=1248034275

ROFL l:)

What's so funny?:confused:

ROFL l:)

I'm with Todd on this one......WHAT?....?.....?:confused:

is the unsharpened pencil trick to see if you have flattop pistons or domes? jim

is the unsharpened pencil trick to see if you have flattop pistons or domes? jim

Huuuummmm....could be....:cool:

What's so funny?:confused:


You can't tell the dome or dish volume of the piston BY poking a pencil in the hole, so Any number you gave him would be an absolute 100% guess.

You guys are way TOO COOL!!! I just pulled the valve covers and the I.D. # on the heads is 14092360. The Engine block code # is (above the timing chain cover) is TC28XXZ9. The heads look immaculate; clean as a whistle. There is still some white paint (ring) around the push rods. Was this factory? How can I tell if a mild cam was installed. It does has a like "lick" to it (or is that just a factory 454?). I know that I'm pushing your patience, but where can I get a kit to wire in my "kick-down" switch on my Turbo 400, on the carb?

Thanks guys

You're the BEST!!

is the unsharpened pencil trick to see if you have flattop pistons or domes? jim

Yes.

You can't tell the dome or dish volume of the piston BY poking a pencil in the hole, so Any number you gave him would be an absolute 100% guess.

I never said that it would give you the size of the dome. It's a simple test to see if there are flat top or domed pistons in there. If one doesn't have a bore scope, it's a nice backyard mechanic trick to check the piston without tearing the top end off the engine. Thanks for your expert criticism though.

Notice I said ballpark compression. Jeff tells us now that he has 360 heads. Those being later open chamber heads, if he was to check and find that he has flat top pistons, then we could give him a "ballpark" compression ratio of about 8 to 1. If he found a little bump in there for a domed piston, then we could give him a best "guess" of about 9 to 1.

Yes, Todd, it is a total guess, but it's about all we have to go on without having the engine apart, right?

Jeff, the 360 heads are what are called peanut port heads. They are not considered the greatest for performance, but they can be made to run strong and they make good low end torque. Trying to guess a camshaft is really tough.

Thanks Bro!! I will do the pencil test tomorrow and report back! I learned something new.

Thanks!!!!

Jeff,

Congrats on the 71.
You only got burned IF the seller was saying "original engine" for the vehicle.
Lots of low buck 454 transplants out there that kick but.
Mine runs low 13s with a basic freshening, some earlier heads, and a modest cam.
I've been working on getting the Elky to go faster rather than tearing into the engine.
Maybe high 12s next time out.

Post a link to pics of the car and engine, ok? Lots of knowledge and ideas here on Team Chevelle. Welcome aboard.
oh, Edelbrock, not Elderbrock

Yes.



I never said that it would give you the size of the dome. It's a simple test to see if there are flat top or domed pistons in there. If one doesn't have a bore scope, it's a nice backyard mechanic trick to check the piston without tearing the top end off the engine. Thanks for your expert criticism though.

Notice I said ballpark compression. Jeff tells us now that he has 360 heads. Those being later open chamber heads, if he was to check and find that he has flat top pistons, then we could give him a "ballpark" compression ratio of about 8 to 1. If he found a little bump in there for a domed piston, then we could give him a best "guess" of about 9 to 1.

Yes, Todd, it is a total guess, but it's about all we have to go on without having the engine apart, right?

Jeff, the 360 heads are what are called peanut port heads. They are not considered the greatest for performance, but they can be made to run strong and they make good low end torque. Trying to guess a camshaft is really tough.


Define "Little Bump"

I knew why you said to use a pencil I just think it's incorrect advice to give him. Sure you can tell a flat top from a domed piston but that's about it.
I wasn't trying to be a butt hole or ruffle any feathers and I never said I was an expert.You couldn't even guess close with a bore scope.It only takes a few cc's on the dome to change the compression. You are going to tell the diffrerence between a 13.8cc dome and a 29.4cc dome with a pencil? The difference is more than one full point of compression. With all the many many different pistons available,not to mention head gaskets, there is no way to know what someone put in it. Sorry I said anything.

I also noticed when I pulled off the valve cover that the valve side of he rocker arm spring had an orange (rubber bushing) type device inside of the spring. What is this for??

Thanks...

It is probably 8.5 or 9 to 1 compression and a low end torque cam (since if was out of a truck) if the cam is original.

It's got some added performance parts on it so I am sure it works fine. Enjoy it!

Sure you can tell a flat top from a domed piston but that's about it.

Sorry I said anything.

That's all the pencil trick is for. It's so a guy with a pretty basic engine can get an idea of what he's got, typically 8 or 9 to 1 engines. This is not to see if it's a 12 to 1 or 13 to 1 enigne, as someone with an engine like that is probably going to a more thorough inspection. Jeff most likely has flat tops in there, so it's an easy way to tell.

No need to be sorry, just be a little more productive with your posts. If you disagree with someones advice, then post some actual words to counterpoint that post. Not just ROFL, that doesn't help anyone. No problem though, I've got thick skin, let's move on.:beers:

That's all the pencil trick is for. It's so a guy with a pretty basic engine can get an idea of what he's got, typically 8 or 9 to 1 engines. This is not to see if it's a 12 to 1 or 13 to 1 enigne, as someone with an engine like that is probably going to a more thorough inspection. Jeff most likely has flat tops in there, so it's an easy way to tell.

No need to be sorry, just be a little more productive with your posts. If you disagree with someones advice, then post some actual words to counterpoint that post. Not just ROFL, that doesn't help anyone. No problem though, I've got thick skin, let's move on.:beers:

:beers:

I also noticed when I pulled off the valve cover that the valve side of he rocker arm spring had an orange (rubber bushing) type device inside of the spring. What is this for??

Thanks...

That spring on the valve side of the rocker arm is called a valve spring. Go figure, huh?:D;)J/K

I think the bushing thing you're asking about is the valve seal. My old heads had orange ones too.

Thanks again Guys!!!

I also noticed when I pulled off the valve cover that the valve side of he rocker arm spring had an orange (rubber bushing) type device inside of the spring. What is this for??

Thanks...

I figured the Spring part (LOL) Just never saw orange valve seals. Is that factory?