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Building a 355 Small Block

  
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Building a 355 Small Block

 
connorIROC connorIROC
New User | Posts: 42 | Joined: 05/11
Posted: 05/29/11
04:13 PM

Hey everybody,

My name is Connor and I'm somewhat new to engine mechanics. I bought a 1987 305 TPI IROC Camaro about a year ago and although that 305 is a pretty mean motor, I wanted a 350. I have done a lot of research on engine mechanics over the past 7 months or so and I have done some beginner auto work such as replacing fuel injectors, fixing fuel pumps, and replacing a rear end in mainly third gen Camaros, but I finally realized that if I am to do an engine swap, I can't learn too much if I can't get my hands dirty.

I was looking at some pre-built motors, but I have so much fun working on my car that I decided that I want to build an engine myself. So, yesterday I found my engine after 6 months of searching. It is a 4-bolt main 350 bored over .60. I got the engine, some 400cid 76cc ported and polished heads, a set of Keith Black pistons (Part #KB119-60), a Weiand TEAM G intake (Part #7530), a 1182 forged crankshaft, some timing chains, a harmonic balancer, some pushrods (I plan on replacing those), a flywheel, and a chrome oilpan and chrome timing cover all for $325. The guy I got it from even threw in an engine stand for me. He said that he had put the motor together for a guy and he put it in his El Camino, took it out, dissassembled it, and then gave it back to him in pieces. He said he had taken the motor to an engine shop and they inspected the cylinder walls and said they are in good shape,  but I know I will have to get most of the parts cleaned up at an engine shop and inspected for cracks. I though it was worth the risk at that price.

Anyways, I want to make my Camaro a street car and I want to get 350-400HP. I was wondering if those heads that I have now are the best way to go. I still need most of the valvetrain--cam, lifters, pushrods, rocker arms. Any input/ideas would be appreciated. I know that I am very new to this but I can learn fast and I am determined. I'm also not in a rushWink

Here are some casting numbers. I haven't managed to figure out the date number of the engine block yet, but I found the casting date on the heads. They are 1971.

Crankshaft
Years:1969-85        Casting:3941182 CID:350 Material:forged Journal:large
Rmain Seal:two     Applications:Z28, Vette,truck, some nitrided
 
Engine
YEARS CASTING CID LOW POWER HIGH POWER MAIN CAPS COMMENTS
1969-79 3970010        350 185        370      2 or 4car,truck,Vette

Heads
Casting No Years CID Intake Exhaust CC
3973493 1971-72  400 ? ? 76cc

The guy said that the heads at some work to the valve sizes, but I won't know exactly what they are for sure until I take them to a machine shop.

Intake:
Weiand TEAM G (7530)

Thanks for your time--

Connor  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 05/29/11
05:24 PM

A 327 crank, 350 block, and 400 heads, that's quite a hodge-podge of parts you got there.  
68scott385 68scott385 68scott385

connorIROC connorIROC
New User | Posts: 42 | Joined: 05/11
Posted: 05/29/11
07:03 PM

Sorry my mistake. I must have misread the crank casting. This is the real crankshaft:

Years:1969-85        Casting:3941182 CID:350 Material:forged Journal:large
Rmain Seal:two     Applications:Z28, Vette,truck, some nitrided

http://s216.photobucket.com/albums/cc264/youcoi/My%20Engine/

Here's a link to some pics of casting numbers and other stuff.  

chevelle83 chevelle83
Addict | Posts: 2280 | Joined: 11/09
Posted: 05/29/11
07:46 PM

whew,,,, OK,,, scott lets explain why,,,,,,,,,,,,,

       the short stroke 327 crank sounds like a good thing,,, but the short stroke combined with the huge chamber heads is NOT gonna make any compression with the flat top pistions.

 If you want to make power,,,,, I would at least go with a 350 crank, those 400 heads are crappy truck heads,,,, you say they have been ported,,,, that helps a little,,, the biggest problem is the huge 76cc chambers, you will need domed pistons to make any compression with those heads.  

The weiand team G intake is terrible for the street!! especially on a small cube engine, that intake dont even start flowing till 3000rpm!  It wants to be on a hot high winding 350 or a 383 minimum!!!  

 the biggest intake I would recommend is a RPM airgap or something like it.  

+1 scott this combo is wierd,,  Yes connor you need to learn about what makes power and torque, cause this combo is obviously not gonna do that.  

You didnt mention a cam,,,, I would but I dont think we are there yet.  

connorIROC connorIROC
New User | Posts: 42 | Joined: 05/11
Posted: 05/29/11
09:49 PM

I just realized that I read the casting numbers on the crankshaft wrong. The crankshaft is actually a 350 forged steel crank. Sorry for the confusion.

Now that I know I have a 350 crank, how does that affect my compression? I should be able to make more with the longer stroke right?

As for the intake manifold, I have heard that dual plane manifolds are better for the street so thanks for your input. You solidified that thought for me. That RPM Airgap looks promising.

I really do want to learn as much as I can. I may not know much but I can learn fast, especially when I like what I am doing. I appreciate everyone's input!

As for the cam, I really want to get the heads figured out first because the guy I got them from said that he had the valves enlarged. I will be taking everything to a machine shop this week to be inspected and checked for cracks.

Thanks a-million,
-Connor  

ldickersonc ldickersonc
User | Posts: 168 | Joined: 05/11
Posted: 05/30/11
10:17 AM

i have a 355 in my 68 camaro, these forums are great for advice, these guys really know their stuff, i'll be dropping in on this on to listen.  good luck with your build  

chevelle83 chevelle83
Addict | Posts: 2280 | Joined: 11/09
Posted: 05/31/11
10:59 AM

what are your intentions with this camaro?   I am assuming all street use??

 Ok  a flat top 350 with 76cc heads usually comes in around 8.2-8.5:1 compression which is fine for daily driver,,,,,  

go with a mild cam with these weak heads, I say no more than .488 lift and 224deg duration @.050  (we can dial in a part number later)   bigger valves in those heads is kind of a waste without some port work,,,,,,,,,,,  

dual plane intake is a no brainer,,,,,,,,,,,,,

650crm carb will be fine,,  any aftermarket hotter ignition will work well.

of course headders and full exhaust will help maintain bottom end torque and be best for street use,

this combo should make a reasonable 300hp and will be nice in a camaro,,,,,,,  

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 05/31/11
11:42 AM

connor, i have the same year and color car, looks like its twin almost.  lol.   i did the 350 carb swap and love it.   lets see how you make out at the machine shop.  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 05/31/11
12:09 PM

Dumb question alert:

Can you use 400 heads with the steam holes on a non-400 block?  
68scott385 68scott385 68scott385

chevelle83 chevelle83
Addict | Posts: 2280 | Joined: 11/09
Posted: 05/31/11
01:22 PM

yes scott you CAN use 400 heads on a 350 block,,,,,,

  but you have to drill the steam holes to use any other heads on a 400 blockSmile  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 05/31/11
01:26 PM

Thanks Chevelle
I knew you could drill holes and use other heads on the 400 block but didn't recall any information going the other way.  
68scott385 68scott385 68scott385

connorIROC connorIROC
New User | Posts: 42 | Joined: 05/11
Posted: 05/31/11
06:19 PM

My intentions are street use. It's my daily driver, but gas really is not an issue.

As far as compression goes, it came with Keith Black dome pistons part number:
(KB119-60). Two of them are cracked because the guy who the engine was built for took it apart and dropped the piston, so I will need to get replacements if I stick with those pistons. So what kind of compression are we talking about with domed pistons? I heard I should be around 9.5:1 with the dome pistons. Also, head gaskets factor into the compression as well right? What headgaskets are good ones?

The heads have been ported and polished, they just need to be cleaned and checked for cracks. I will hopefully be taking everying to the machine shop this weekend to have it all checked and cleaned. Once this is done, I will know more about the valve sized and ports. A mild cam sounds good to me. I want something will a little lop in the idle but not too radical. And I have one qestion about the valve train: I am going with a hydraulic cam/roller lifter setup so do I need a specific pushrod for it? I heard I can just call a place like summit and they will set me up with a valve train setup good for my application. Also, I am 75% sure I am going with the partial roller rocker with the roller on the valvesteam. Would that be a good setup?

As far as carbs go, I wanted to go with holley, but I am leaning toward Edelbrock now. I know you can get a lot more out of Holley though, it just takes some adjusting.

Exhaust: Magnaflow!! I love the way it sounds. I have some Hedman smog headers on there now but I am going to get new ones eventually. I want 1 5/8 inch headers. Not sure what brand yet but I want long tubed because that's what I have on there now.

@rednechjoe: That's awesome man! I love my Camaro. I need to make a good name for the 3rd gens here in Port St. Lucie. Too many rice burners... not that the 305 isn't already faster than most of them Wink.. Thanks for the post and also for the support at the machine shop--I hope it checks out OK.

Thanks for all the comments and ideas. I really appreciate it! I'll keep you all updated with some pics when it all gets machined.  

Skylark Skylark
Guru | Posts: 1481 | Joined: 02/10
Posted: 06/01/11
05:16 AM

Please take 25.00 dollars and go buy THE BOOK.how to build SB chevy motors by David Vissard. PLease buy the book and read it cover to cover Twice!!!!!.You think youv'e got questions Now wait till you read the book.Hey Joe,where you going with that..whoops,hey Joe st. lucie is in your hood ain't it.  

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 06/01/11
05:45 AM

ah, some jimi hendrix?   ....gun in your hand?  lol.     im over around tampa, the other side of the state.   good suggestion on the book.  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 06/01/11
11:04 AM

Spelling Police...Vizard...just to help locate books by author filter.

Anyone without an engineering degree would have to read his books twice to understand everything he says.  
68scott385 68scott385 68scott385

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