Jump to content

rebuilding a 350 Chevy engine


blazinjr
 Share

Recommended Posts

First off I have rebuilt 2 302 Ford engines and a 2300 Ford engine so I do have the tools and some know how.

 

The engine is out of a 1977 C10 pickup and I checked the numbers on the front of the block and it is the right engine for that year truck.

350 2 bolt main

 

The engine smoked a little and had a little noise in the top end.

 

I took the engine apart and starting cleaning and inspecting the old parts.

 

I found the noise... #6 cylinder exhaust lobe was worn down and the lifter had some scaring on it.

 

Now for the questions.

 

All of the bearings look stock and are stamped with GM but the rear one is stamped GM also but it also looks like there is a 001 stamped on the back side. If the crank had been machined in the past wouldn't they have turned all of them to that?

 

Also the pistons are the four valve releif dished pistons with the outer tapered edge, but nowhere on them do they say GM. On the center of each piston there is a letter, some have a H, J, M, and a K. Do the stock pistons have these letters marked on them?

 

I was just planning on buying a rebuild kit from Northern Automotive and honing out the cylinders and putting it together myself, without having to send it to a machine shop. I did not want to spend a fortune on rebuilding it, it is just going to be a work truck and driven around 2 miles a day.

 

Anybody help me out?

Link to comment
Share on other sites

The .001 is a factory undersized bearing used to keep everything in spec. This was and is often done in the assembly plant. If the crank was turned it would have been at least .010" under not .001"

 

ALWAYS bore and hone a block for a rebuild unless it has next to no milage like a race motor that is freshened at least once a season. A ridge forms at the top of the bore after years of use, if this ridge is not taken down to the new bore size, the top piston ring will crash into it and either break, never seal right or both.

Link to comment
Share on other sites

sometimes he speaks the truth

 

the block should ALWAYS be checked however if there is not signifigant cylinder wear only a hone and not a bore would be the cheaper way to go

 

if it was me and it just had a bad cam lobe I'd replace the cam and lifters and maybe the timing set and keep driving it.

 

whatever you decide to do a CLEAN work area is the key to success one spec of dirt on a bearing and its toast

 

good luck with your project

Link to comment
Share on other sites

Not much cylinder wear at all. I used a ridge reamer on the first couple holes but then just used a green scrubber from the kitchen and soaked it in engine cleaner. It removed the carbon build up, but I sprayed it and let it set for a day too. Running my fingernail up over the cylinder wall to the top I could not feel any lip. When I start to hone it I will see a low spot if there is a ridge.

 

I will be picking up a mic to check the bores tomorrow.

 

Last time I rebuilt an engine was back in 1997. It was a challange from a friend to see who could build the fastest car for under $1500(including the car). It was a 1978 302 with 68,000 miles on it. I built it out of spare parts. 1978 block, 1985 heads(non adjustible rockers), 1983 intake, 1991 Mustang pistons and rods, and a 1983 flywheel balanced to a 78 crank(via Performance research) and a Crane Cam. I put it in a 83 Mustang GT Ttop and logged about 45 passes at National trails that summer and fall then sold it that next winter for 2 grand. That car is dead now but that engine is still running around in a mid 80's Tbird.

Link to comment
Share on other sites

Guest 614Streets
Go with the nothern rebuild kit , its a solid investment and cheap as fuck. You can get away with a hone if you have a buddy mic the walls and if its not outragiously worn ridge and hone. Iys been common practice to hone with a drill on 2 stroke outboards for years to present just checking out of round , taper , etc , and 4 strokes are really no differnt minus the valve sealing , but oversize and a bore and ck10 hone will make it last. Its really about money and nothing else. Think about it enough yourself im sure youll find a solution.
Link to comment
Share on other sites

what did it run? just curious

 

First pass it put down a 14.4 with a 2.3 60 ft time, stock 7.5 rear end gearing, 4 spd(side load shifter), 225/60/14 Goodyear tires,

 

I borrowed a friends set of tires at the track for a couple passes. Dropped 60 ft time down to 1.9s and dropped 1/4 mile down to 14.0Xs.

 

All in all I had about $500 in the engine. $900 in the car.

 

And I ended up winning the challenge, His one wheel peeling TA couldn't get traction and only ran low 15s and high 14s.

Link to comment
Share on other sites

Ok on the main bearings...

A capital "A" with a circle around it

GMM400

5463372

20 J

0006

 

On the rear main block side it has...

A capital "B" with a circle around it

GM

H35LT

001US

2 77

 

Cap side..

57801

"A" with a circle

GMM400

001

3807

Link to comment
Share on other sites

There was a little more of an ridge than I thought. I used the ridge reamer a little more then started to hone them out. After honing out the cylinders I found one that is 4.005 and all the rest is 4.003 to 4.004. An old guy down the street told me that as long it is no more than .005 it would be alright.

 

Should I go ahead a put it together?

 

What do machince shops usually charge to bore and hone out a block?

 

 

Anybody know any desent shops around Lancaster?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...