Motor Rebuild - Texas 4x4 Forum

Go Back   Texas 4x4 Forum > Technical > Gas\Diesel Engine & Transmission

Photo Gallery Places to Wheel Gallery III Home Forum Tech Section IRCChat FlashChat

Gas\Diesel Engine & Transmission Engine, Transmission, Transfer case

Texas4x4.org is the premier All All Forum on the internet. Registered Users do not see the above ads.

Gas\Diesel Engine & Transmission:

Motor Rebuild



Reply
 
Share LinkBack Thread Tools Display Modes
Old 02-11-2010, 12:09 PM   #1
Flex Master
 
Join Date: Mar 2008
Location: Rockwall
Posts: 1,652
BlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afar
Motor Rebuild

Okay so the weak and leaky 350 that was in my blazer gave out so i want to build a pretty hot 355 since this truck is no longer my dd. I have never rebuilt a motor but i have done some reading and have a few questions.

1. What kind of cam would be good for low end torque motor? Specific specs?

2. Has anyone here ever swapped out stock heads for vortec heads? Was it worth it? What problems did you run into? Any downsides?

3. I have access to 2 blocks to build but dont know which one. I have a 96 vortec block with a spun main bearing but with no fuel enjection stuff. or i have a stock 76 350 thats pretty much complete.

4. What other types of heads sould i look for? I priced out some AFR heads and they are a little to pricy for what im looking for and i dont think i would use them to their full potential.

I may have a few more questions so i will update this later.

Thanks in advance.
Kyle
__________________
Kyle
1984 K5 Blazer
WORK IN PROGRESS
TBI 355/sm465 - 241/205 Doubler
60/14 with 4.56s.

Tow Rig/DD: 2005 F250 CCSB 4x4

Last edited by BlazerBoy; 02-11-2010 at 05:22 PM..
BlazerBoy is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 02-11-2010, 01:08 PM   #2
Trail guide
 
Join Date: Sep 2009
Location: Amarillo, TX
Posts: 263
hotrodbill Axle snapper extrordinairehotrodbill Axle snapper extrordinairehotrodbill Axle snapper extrordinairehotrodbill Axle snapper extrordinairehotrodbill Axle snapper extrordinaire
It all depends on how much you want to spend.

I could spend all day on what you COULD do, but the only thing that matters is what you can AFFORD to do.

1. What kind of cam would be good for low end torque motor? Specific specs?

Depends on the transmission. Automatics respond differently than manuals, torque converters make a difference too. Two IDENTICAL motors, with different torque converters will perform differently. Then there is gear ratios that also make a difference.

2. Has anyone here ever swapped out stock heads for vortec heads? Was it worth it? What problems did you run into? Any downsides?

Yes, I've done it. It's not worth as much as those people trying to sell them would have you believe, especially on a motor built for torque rather than horsepower. Vortec heads don't start to shine untill about 4500-5000 rpm's, by then you are out of your torque window.

You HAVE to run a Vortec intake manifold, and self aligning pushros or guide plates. Vortec heads are light, and prone to cracking, so a magniflux is a must.

3. I have access to 2 blocks to build but dont know which one. I have a 96 vortec block with a spun main bearing but with no fuel enjection stuff. or i have a stock 76 350 thats pretty much complete.

With a spun main bearing, the 96 block is pretty much junk. It will have to be align bored to be used again, thats usually not a cheap procedure, and there is a chance it cannot be salvaged if there is too much damage to the top bearing saddle The crankshaft may also be junk if the damage is too extensive to machine out, you may be better off with a new crankshaft. The upsides are it is a roller block, therefore you can reuse all the factory roller cam hardare if the block is salvageable.

With the age of the 76 block, it will probably need it's fair share of machine work. Possibly as much as the 96.
------------------------------------------------

So here is the bottom line, if the blocks and crankshafts need a lot of machine work, you might as well build a 383. It will cost a little more, but they are known for thier torque, which is what you wanted in the first place.
hotrodbill is offline   Reply With Quote
Old 02-11-2010, 01:23 PM   #3
Trail guide
 
Join Date: Sep 2009
Location: Amarillo, TX
Posts: 263
hotrodbill Axle snapper extrordinairehotrodbill Axle snapper extrordinairehotrodbill Axle snapper extrordinairehotrodbill Axle snapper extrordinairehotrodbill Axle snapper extrordinaire
Heres what I would do.......

Take the 76 apart, and have the block and heads checked out to make sure they are good.......If so, sell the Vortec engine to some sucker and use the money to buy a 383 crankshaft.

Build a strong bottom end with good rods and ARP rod bolts. Use a camshaft that specs around .420 lift and 270 duration. (Elgin E923M, Howards CL112011) Don't be fooled into puting a rauncy cam in there, you want to maintain a good idle and bottom end power. Any cam more than that and you will need to upgrade all of the valvetrain also.

Get a Crosswind intake manifold, good carburetor, headers, and good distributor. Don't put wore out junk parts on your new engine.

If that doesn't give you the torque you want, then you need to step up to a big block.
hotrodbill is offline   Reply With Quote
 
Old 02-11-2010, 04:39 PM   #4
Cooler'na13floorelevator
 
4x4Freak's Avatar
 
Join Date: Dec 2002
Location: Kermit, TX
Posts: 6,117
4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis
I would look at the Comp Cams Xtreme 4x4 cams. I have run the second from biggest one before in a 350 and it worked pretty well. With stock heads and a 600 edelbrock it would run up to 6k rpm with no problem and it had lots of low end torque also. It was also bored .030 with flat top KB pistons and an edelbrock performer intake.

If I were to build a 350 now I would stroke it. Back when I built mine the stroker cranks were still expensive. You can find complete rotating assemblies pretty cheap now. Check out speedway automotive and race mart for good deals on parts.
__________________
Zach


Quote:
Originally Posted by RVREDDOG
Thats pretty much how I feel about it....You gone yet?
Reality is an illusion caused by the absence of alcohol.

75 IH Scout II
79 Chevy K10
80 GMC K25
97 Chevy S10
05 Dodge 3500

Collect the whole set.
4x4Freak is offline   Reply With Quote
Old 02-11-2010, 05:12 PM   #5
Flex Master
 
Join Date: Mar 2008
Location: Rockwall
Posts: 1,652
BlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afar
Thanks for the input guys. The vortec block isnt technically mine. Its my dads and i have a chance to buy it from him. Its just been sitting and if i do want it it will probably still be there.

Bottom line is i want a motor that is realiable but has plenty of power. I was looking at the 383 rotating assemblies and they were pretty much all around 800 bucks which isnt bad but i want to see what i can salvage from the 76 block i have.

I really cant decide weather i want to go 383 or just rebuild the 76 to a 355.

The 383 would be great but i am kind of tight on money right now. Either way this is going to be a slow build so i can spend more money where is counts but i want to get the truck running as soon as possible.

This being my first build i dont know if i will be able to put together a 383. Not that i dont trust myself i just dont know enough about motors to make the proper decisions on what is tollerable and what is not.

I kinda like the idea of building a wicked 355 so when i out wheel some people i can tell them its just a 350. Haha

With those cam specs will i still be able to drive it around town if i wanted. I dont want something so lopey that i have to be on the gas constantly to keep it going.

As for the transmission i am running a 32spline sm465/205 combo with 4.56 gears. Right now i have some 36in military tires on it but i will prolly end up running some 36 to 38 in boggers or something like that.
__________________
Kyle
1984 K5 Blazer
WORK IN PROGRESS
TBI 355/sm465 - 241/205 Doubler
60/14 with 4.56s.

Tow Rig/DD: 2005 F250 CCSB 4x4
BlazerBoy is offline   Reply With Quote
Old 02-11-2010, 05:19 PM   #6
Flex Master
 
Join Date: Mar 2008
Location: Rockwall
Posts: 1,652
BlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afar
As for heads should i look for some Double hump 2.02/1.94 heads? My dad has a pretty wicked 355 small block in his landcrusier and it has some ported and polished double humps and he says that its a pretty hot little motor with the cam it has. If i remember right i saw a set of the same heads on craigslist on for 100bucks but they needed to be worked.


Since this is my first motor i want it to be done right so i am not going to set a budget or anything so that i wont cut corners to keep the cost down. I want to pay the extra money to have the whole rotating assembly balanced perfectly so this motor will last a long time. If it takes me a little longer to build this motor right so be it. I would rather wait then slap something together and rip itself apart.
__________________
Kyle
1984 K5 Blazer
WORK IN PROGRESS
TBI 355/sm465 - 241/205 Doubler
60/14 with 4.56s.

Tow Rig/DD: 2005 F250 CCSB 4x4
BlazerBoy is offline   Reply With Quote
Old 02-11-2010, 05:31 PM   #7
Cooler'na13floorelevator
 
4x4Freak's Avatar
 
Join Date: Dec 2002
Location: Kermit, TX
Posts: 6,117
4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis4x4Freak Surfs Venus with Anubis
I was running it in front of a messed up th350 with stock converter, 2.76s (yes, 2.76), and 33s. I put a lot of miles on it both in town and on the highway and it did fine. The idle was pretty smooth, it was just rough enough that you could tell it had a bigger cam in it.

I would recommend running at least a 750 cfm carb. I tried running one on mine and it would flat out run, but it had a dead spot at mid throttle that I could not get rid of. I ended up just running the 600 on it instead. I'm sure I could've gotten it tuned out, but I didnt have the time or money for tuning parts back then.

I would budget at least a couple thousand dollars if you want to build a decent engine, especially if you have to do very much machine work.
__________________
Zach


Quote:
Originally Posted by RVREDDOG
Thats pretty much how I feel about it....You gone yet?
Reality is an illusion caused by the absence of alcohol.

75 IH Scout II
79 Chevy K10
80 GMC K25
97 Chevy S10
05 Dodge 3500

Collect the whole set.
4x4Freak is offline   Reply With Quote
Old 02-11-2010, 07:26 PM   #8
Wheelin MadMan
 
Join Date: Aug 2008
Location: Weatherford, TX
Posts: 780
chvyracing08 Spotterchvyracing08 Spotter
do a roller valvetrain setup pricey i know but well worth it. get you a comp torker cam or whatever they call them and never look back!
__________________
grab my keys get the we're goin for a ride.
82 chevy short wide, 14ff w/detroit, d60, 12v cummins, nv4500hd,205,395/85/r20 mvt's (always under construction)
chvyracing08 is offline   Reply With Quote
Old 02-11-2010, 07:28 PM   #9
Wheelin MadMan
 
Join Date: Aug 2008
Location: Weatherford, TX
Posts: 780
chvyracing08 Spotterchvyracing08 Spotter
and oh yes do the vortec swap. i ran a old 350 with some plain ol 882's forever. blew it up, then built a basic stroker with vortec heads and wow day and night difference. btw vortec heads like high duration cams. seen it in person on a flow bench and its pretty sweet
__________________
grab my keys get the we're goin for a ride.
82 chevy short wide, 14ff w/detroit, d60, 12v cummins, nv4500hd,205,395/85/r20 mvt's (always under construction)
chvyracing08 is offline   Reply With Quote
Old 02-11-2010, 10:51 PM   #10
camel humper
 
Join Date: Mar 2006
Location: Rosebud, Tx. / Baghdad, Iraq
Posts: 1,920
dragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubisdragoonranch Surfs Venus with Anubis
Another vote for the 383.
__________________
Ed ( Sultan of Sand )
'78 Chevy Big-30

https://www.amsoil.com/dealer/websit.../atvbanner.gif

Click here to check out our online store.
AMSOIL Your last stop for all your Automotive Synthetic Lubricant needs.
Please PM me for quotes or questions.

Click here for places to wheel in Texas
dragoonranch is offline   Reply With Quote
Old 02-12-2010, 02:36 PM   #11
Flex Master
 
Join Date: Mar 2008
Location: Rockwall
Posts: 1,652
BlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afarBlazerBoy is a splendid one to behold - from afar
http://www.hdmaddog.com/Chevrolet-GM...-p6662413.html

What do you guys think of this kit? Anyone use it before? This isnt the cheapest place i have found it but how good of a company is Eagle?

Any other kits i should look at?

I have pretty much decided that since the only thing i wouldnt be replaceing on this motor would be the crank why not replace it and go with the 383.
__________________
Kyle
1984 K5 Blazer
WORK IN PROGRESS
TBI 355/sm465 - 241/205 Doubler
60/14 with 4.56s.

Tow Rig/DD: 2005 F250 CCSB 4x4
BlazerBoy is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 02:25 PM.


3.8.8 - Powered by vBulletin
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright 2002-2012 Texas4x4.org
 

SEO by vBSEO 3.6.0