[drydockedinaz]

hello, I bought a 1977 corvette for my wife. I bought it with a blown 350 motor. the person I got it from had it rebuilt from the tires to the t tops. he drove it about 2500 miles and put a piston through the cylinder wall. once i diassembled the motor it looks like the shop didnt tourque the connecting rods right. The guy went back to the shop for warrenty but the owner died the week before. The shop was closed. I bought another 350. I want to take some of the parts from the blown 350 and put them in the other one I got. Its a 3970010 block bored 30 over. The blown motor had a clay smith cam, PBM hydraulic roller lifters, double timing chain, newly rebuilt heads, high volume oil pump, stainless steel crome polished valves. It had the double springs but when I was taking it apart I noticed the inner spring on five of them were broken. it was not because of heat there was no blueing and when the motor went it froze up the piston wraped around the crank. MY question is what would cause this. I am concerned that the push rods were to long.It has a 280 advertised, 230 at 50, 112 lobe center and .480 lift. most of that I dont even understand. the heads have been decked 202 intake 150 exhaust. The push rods I took out were 7.29 Im going to use felpro gaskets. I dont know much about this subject any info on this would be helpful. Also should I just say the heck with this 350 and make it a 383.

[lmsport]

Are you sure that the inner spring you are looking at is not just a damper?

This is a single spring with a damper.



If the damper is broke, the spring is probably getting too close to coil bind.

[vinniekq2]

Are you sure that car is for your wife? They are low,hard to get in and out of,poor vis,ride rough,noisy.She will need to be kind of taller for a woman to see where she is going and to parallel park.She wants more power? I would think mileage,,,

[68NovaSS]

Originally Posted by vinniekq2

Are you sure that car is for your wife? They are low,hard to get in and out of,poor vis,ride rough,noisy.She will need to be kind of taller for a woman to see where she is going and to parallel park.She wants more power? I would think mileage,,,

That's funny...I have a guy interested in my T-Bucket "for his wife", mainly because it has a BB in it, she would like that...yeah, right!

[cobalt327]

Originally Posted by drydockedinaz

hello, I bought a 1977 corvette for my wife. I bought it with a blown 350 motor. the person I got it from had it rebuilt from the tires to the t tops. he drove it about 2500 miles and put a piston through the cylinder wall. once i diassembled the motor it looks like the shop didnt tourque the connecting rods right. The guy went back to the shop for warrenty but the owner died the week before. The shop was closed. I bought another 350. I want to take some of the parts from the blown 350 and put them in the other one I got. Its a 3970010 block bored 30 over. The blown motor had a clay smith cam, PBM hydraulic roller lifters, double timing chain, newly rebuilt heads, high volume oil pump, stainless steel crome polished valves. It had the double springs but when I was taking it apart I noticed the inner spring on five of them were broken. it was not because of heat there was no blueing and when the motor went it froze up the piston wraped around the crank. MY question is what would cause this. I am concerned that the push rods were to long.It has a 280 advertised, 230 at 50, 112 lobe center and .480 lift. most of that I dont even understand. the heads have been decked 202 intake 150 exhaust. The push rods I took out were 7.29 Im going to use felpro gaskets. I dont know much about this subject any info on this would be helpful. Also should I just say the heck with this 350 and make it a 383.

There can be several causes of broken valve springs and/or dampers. Among them are over revving, incorrect installed height, spring mismatched to cam, coil bind.

While you're in there, check everything to do w/the valve train including the geometry to be sure there's no problems.

Roll all the pushrods on a flat surface like plate glass to be sure none are bent. If they are bent, you'll hear the tell-tail *tick* tick* tick* as the p-rod rolls across the glass. If any valves made contact w/the pistons, the valves will need to be checked for straightness and the valve-to-seat seal needs to be checked as well.

Replace ALL the springs w/springs w/the correct specs for the cam- all manufacturers will have spring recommendations for their cams.

Good luck.

[drydockedinaz]

thanks for the response. To answer the question is it for my wife. Thats what I'm telling her. She has always wanted the stingray and now that the kids are on there own its time she gets something she wants. She has always had sports cars and hates to be second off the line. Regarding the springs Imsport is right its the damper. I thought it was a double spring. I have checked the valves and push rods. A intake and exhaust valve were bent and the push rods also. Im going to bring them to a shop in phx. to be checked. I still haven't made up my mind if im going to rebuild the other motor I bought or buy another. I looked at a 383 in phx. yesterday only problem I don't know if I can put a 1991 l1 in a 1977 without changing a bunch of other stuff. The motor I looked at is on craiglist the header for it says 383 stroker check this out. listed in phoenix. If anybody has time to check it out and let me know if somthing like that would work it would be very helpful. Im in a small town and pickups are the thing around here.

[geezer69]

you got any pics? i had a 77,t-tops, silver car. purdy nice but slow in stock form.

[JeffB]

Maybe you should check out these guys: Chevrolet Small Block - Tuff Dawg Engines located in Phoenix and get an engine with a warranty,from the damage you describe I would be leery about using parts from the blown motor unless they are inspected by a machine shop.

[Merkur87]

I would be very nervous about swapping parts over. While I do not mean this in a derogatory way it sounds like your engine building experience is very sparse and there are a thousand little things that can cause an engine build to go south in a hurry. You've already seen that with the current blown engine.

The camshaft should be examined closely because it's very easy for cam lobes to become damaged when there are other valve train issues. Sometimes the damage is so slight that a magnifying glass may be in order to inspect for microscopic pits and nicks which can turn into craters and gouges. The same goes for lifter rollers and so on.

What would I do if the car were mine? I'd drop a 454 in it. The late 70s are the last of what I consider the pretty Corvettes. The next generation of Corvette was hideous and the current ones (while high tech and nice) still lack something; at least in my opinion.

[vinniekq2]

even though the c-3 does not handle well,a BB would make it worse.stick with a small block just so its nice to drive.
If you plan to keep this car for a long time? reason to ask is because you could spend more on the car than the car is worth,,,
buy a kit to swap in the LS style of engine.Find a low mileage or stock rebuilt LS-3,(if you add the hot cam and clean up the heads+ 475 HP)LS-3 is smooth idle decent mileage,reliable,and 430 HP. expensive to swap in,just an idea.
a low 13 second car and 18 plus mpg,,,

[ap72]

Originally Posted by vinniekq2

even though the c-3 does not handle well,a BB would make it worse.stick with a small block just so its nice to drive.
If you plan to keep this car for a long time? reason to ask is because you could spend more on the car than the car is worth,,,
buy a kit to swap in the LS style of engine.Find a low mileage or stock rebuilt LS-3,(if you add the hot cam and clean up the heads+ 475 HP)LS-3 is smooth idle decent mileage,reliable,and 430 HP. expensive to swap in,just an idea.
a low 13 second car and 18 plus mpg,,,

you can get over 400hp out of a 5.3L fairly easily and those are MUCH cheaper. If cost is a concern I'd give that route a serious thought.

[painted jester]

I came in for lunch, and saw this thread, I have a 77 vette
and work on a lot of early vettes! I hate the big blocks to work on!! You cant get a soda cracker in the engine compartment there's no room! They are hell to work on

The suspention is easy to tune for a good ride, G.M had many options available for twisty road coarse, highway and performance. Im running the gymkhana suspension with 9 leafs in the rear spring . The other thing is the rear wheels have the alignment set periodically caster camber. that many owners don't know and some shops!!!LOL I changed some suspension parts and a wheel bearing on the rear and asked a shop to check my alignment when I went to pick it up I asked how the rear caster camber checked out they didn't know it had caster camber adjustment, If you go to wide tires and rims you may not get a full foot print without changing the caster camber, the weight of the car could be concentrated on the outside edge of the rear tires! thats why a lot of guys go to solid rear ends! Especially during hard launches you lose traction if the caster camber is Not set for the width of the tire which will be different then the stock setting!

Im 6' 2" medium build I hate getting in and out of it but once in I enjoy driving it my wifes 5'3" medium build she gets in it like a wet worm!!!

Well I came in for lunch but havnt eaten yet LOLThen Im going out in te cold to fiddle around on a '79 Comaro I bought for my wife!!! LOL

Jester

[painted jester]

Originally Posted by ap72

you can get over 400hp out of a 5.3L fairly easily and those are MUCH cheaper. If cost is a concern I'd give that route a serious thought.

Cant you put in an opinion without Quoting Vinny or anyone else? it makes it look like your saying their wrong!!!!!!

Jester

[painted jester]

Originally Posted by painted jester

Cant you put in an opinion without Quoting Vinny or anyone else? it makes it look like your saying their wrong!!!!!!

Jester

Its 12:12 pm here but the time of this post says 9:59 are your times right where every one else is?

[Merkur87]

I only mentioned the big block as a suggestion of what I would do if the car were mine because I love cubic inches. :-)

A bit more hassle on serviceability is not that big an issue for me as I've been a mechanic for many years. Scraped knuckles and profanity is the norm...... :-)