Hi!
I need suggestion about rebuilding .
I have a 305 tpi trans am 170000 miles on it.
I think(not sure need compression check) I have worn valves or piston rings or some worse.
What you guys think could I do it or better to take it to machine shop or buy a rebulit one?
Has anybody done this kind of job before? How long does it take from pulling engine to start it?
If I'd do it which engine kit you recommend? Which techbook is the best for this job?
I don't wanna sell my car in this condition for $1000 rather I'd put some work in it and keep it.
Thanks:
Pyr

 

Without knowing what it does to make you think it needs a rebuild, most likely your problems are concentrated in the heads. May also have a worn out cam and somewhat worn bearings.

But, this is the perfect excuse to put a 350 in there. Crate, rebuilt, junkyard core rebuilt - each has its pros and cons. With a crate or rebuilt, you could start on Friday evening and have it running Sunday afternoon, if you have everything arranged beforehand (engine hoist, new hoses & belts, gaskets, etc.).

Rebuilding a junkyard engine would take a machine shop to do the boring and the like, but you should be able to assemble with a shop manual, loaner tools, and perhaps some experienced guidance from time to time. Figure on a few weeks to get it disassembled, machined, and reassembled. Install would be the same Fri-Sun as above.

 

I would suggest the 350 only because you can go through the whole thing have it rebuilt usually a little cheaper than the 305 but, real close (depends where you buy the parts) and when it is done you basically swap the eng. so your down time is minimal plus you get a few extra hp

 

I can get a 305 engine from a 88 camaro with no tpi just engine and heads for $60. I tought I could do the job on this engine and I'll just change them.
What do you think?

 

If it's a TPI engine, yes (although the intake bolt angle on the heads will be different than yours). If it's a TBI engine, at least not the heads.

Personally, I would only do it if the shortblock doesn't need rebuilding - i.e., rings, pistons okay. Would possibly consider it even if cam and cam bearings were replaced, but as soon as you put machine shop money into a 305 shortblock, your HP return-on-investment starts shrinking.

 

I tought I taw a putty cat.


Sorry, couldn't resist.

 

the rebuild i did on my LG4 cost me about $1000. i got a few deals here and there.

a 350 rebuild will cost less money, or about the same, depending on what all you decide to do to it. keep in mind though, as five7 said, that the 350 will make more power than the 305.

if you want to keep the car original, do the 305.

if you want to make it fast for cheap, go with the 350.

 

I am currently rebuilding an '86 z28 with a 305 with a carb.

It took me and a friend about 18 hours to pull the engine completely from the car, but this is mostly cause we encountered a horrendously seized bellhousing bolt that we eventually had to break. I would say it would have taken us only 10 - 12 hours had we not ran into this problem. However it was not a TPI engine.

A reference source I recommend is Chiltons (of course) and the S-A design book "How to build the Smallblock Chevrolet". This is an excellent book that will lead you step by step through the whole process of rebuilding the engine yourself if you choose to do this.

Someone please correct me on this if I am wrong, but from what I can ascertain the F-body cars built in 1986 had either the 1985-1986 version of the block but many had the 1987 and up block (from what I am told, cars that were built later in the 86 model year). This can make things a bit tricky as far as buying a rebuilt kit goes. However chances are if you have centerbolt valve covers you have the 87 and up version of the 305.

In rebuilding this 305 you have to use a hydraulic cam and chances are your stock lifters are done for which means you'll need a new hydraulic cam and new hydraulic roller lifters which are more expensive than regular cam setups.

A nice way to add some power is to up the compression a bit, stock it was 8.6 on the LG4 5 liter block. Federal Mogul sells a piston for the engine that has 9.6 compression, from what I am told this will net you 10 - 15 hp. I got a set with moly rings for $180 after tax.

Federal Mogul also offers stock crankshafts with a core exchange for $225, I purchased one from my local machine shop.

My rebuild isn't currently done, but using the book, thus far it has been rather straight forward and while it hasn't been easy its hasn't been overtly difficult.

 

Hi!
Don't you recommend rebuild kit to do the job?
I saw a kit from PAW (performance automotive warehouse) for $350.
Pistons, sealed power piston rings, rod & main bearings, premium engine gasket set, oil pump, camshaft & lifters.
Hidraulic lifters extra.
So I tought I coluld be around $400 plus $60 for the engine.
What do you think?
Does anyone know better for less?

 

my machine work ran me approximately $200 for the block, crankshaft, and a set of heads that i ended up not using.

i had the block hot-tanked, new core plugs installed, new cam bearings, had the block checked for cracks, and had the cylinders honed to get a fresh surface for the new pistons and rings i was installing.

i had the crankshaft tanked, checked for cracks, and polished.

the set of heads that i took in were hot tanked, and checked for cracks.

i got lucky, and the shop i went with had good word of mouth advertising. ask around if you end up going the rebuild route, and also check prices on shops in your area.

 

86 and 87 LG4's already had a flat-top piston, giving them 9.5:1 compression.

the pistons in my 81 LG4 that i rebuilt needed to be replaced, and i wanted flat tops anyway. my machine shop (b&b automotive in warren, ohio) was willing to offer me a set of enginetech flat-tops with set of moly rings for ~$120-$130 iirc. he cut me a break on the pistons since i had already brought all my machine work to him for this engine.

 

pyrrano: If you are doing a more mild rebuild I would recommend the kit, however, personally I didn't really like the cam PAW was offering, but the kit does save cost.

robertg: I stand corrected, they did have 9.5 compression. However I would say that by comparison the stock pistons look to be dished somewhat (a small amount) and not totally flat by comparison to aftermarket flat top pistons. ::shrug::