PONTIAC ZONE TECH FORUMS
 

Go Back   PONTIAC ZONE TECH FORUMS >
Engine Tech
> " TURBO BUILDS "
User Name
Password

" TURBO BUILDS " Post your Turbo build-Up or any that you have in process

sponser links

Reply
 
Thread Tools
Old 01-13-10, 11:05PM   #1
Ondatrack
Registered User
 
Ondatrack's Avatar
 
Join Date: Jan 2008
Location: Hemet, CA
Posts: 9
Default My 301 Turbo Build

Here is some information on my 1981 Turbo 301 buildup. Before I get all the usual comments I want to say that I realize this is a less than optimal draw thru set up and these engines are in stock form considered weak at best. They canít rev and they donít breath plus the cranks are weak. I have three 455s and two 428s along with a 400 I could use but I wanted something different that would be a challenge. I want the 301 to put out close to double the factory horsepower without breaking the crank or blowing a head gasket. To begin with my goal is a fast and reliable street car that I will drive on a regular basis around 100 miles a week to and from work. I use my 95 Firehawk for that currently but I wanted a traditional Pontiac powered car for that duty and I want my 81 Trans Am to be about as fast as the Firehawk. I have a 455 64 Lemans that I bracket race that will be getting a turbo build up next so this will not be my race car. G-pop Shop in Arkansas converted the original Garrett T-3 it to a T3/T4 hybrid with porting done to the turbine side. I used a 60 trim compressor wheel and stage three exhaust wheel. The turbo should be good for around 50 lbs of air. I had the turbine ceramic coated at the same time and I will coat all of the pre turbo exhaust parts as well. I then had a mandrel bent 2 Ĺ inch down pipe made and have an electric cutout before the 3 inch Dynomax Metallic Cat.
I ported the odd 301 heads and enlarged the valves to 1.90 and 1.60 stainless valves along with machining them for larger springs and positive oil seals. I flow bench tested the heads at Westec in Mira Loma CA and they now flow as much as my stock 6X heads. They flow 207@.500 intake and 167@ .500 on the exhaust side. They originally flowed 172 intake and 125 on the exhaust. I chose a Comp Cams custom grind with 206 intake and 212 exhaust at.050 with a 114 lobe separation and the intake ground on a 112 centerline. The lobes are their extreme energy lobes similar used with their XE250H stock grind. The lift is .475 intake and .488 exhaust with the 1.65 full roller rockers. This is a smaller cam than I was originally thinking but I wanted the idle to be good since I still need to pass Californiaís wonderful biannual smog inspection. I have a set of Rhoads lifters that I will be using to smooth the idle even more and to build more cylinder pressure in the lower rpms before the boost kicks in. I ported the plenum, the intake and the exhaust manifolds. Dave Crower ran all my information through his computer program including turbo compressor data and came up with a similar grind recommendation but he could not get quite as much lift on this short of duration cam. He showed max HP of 417 at 5500 rpm and 462 lbs torque at 3800 rpm.
I am using ARP head studs for a little extra insurance since I wanted to be able to push the boost to 15lbs. I have a set of Cometic multi layer steel gaskets along with ARP Studs. I hated the idea of putting $220 in new ARP bolts and resizing and still having a cast rod and cast pistons. After measuring everything I bought a set of used Carrillo H beam 6.35Ē rods that have the 7/16 SPS Carr bolts which are the best made. These rods are for a 2 inch journal crank and are .902 wide vs. .900 for the stock rods and the side clearance came out fine. They weigh 605 grams. I found Probe forged lightweight dished pistons new on E-Bay with a 4.030 bore and a 1.28 compression height that will work with the long rods to put me within .005 of zero deck. The pistons have a 22cc dish and weigh 425 grams plus the pin weighs 117 grams. Iím using 1/16, 1/16/ 3/16 file fit JE plasma moly file fit rings. The pistons are originally listed as a Ford 408 stoked Windsor. I checked for piston to valve clearance and no problems. This took over 1/2 lb off each rod journal and should help make the crank live to 5500 rpm. I had the block bored, honed with a torque plate, decked and the rotating assembly balanced.
I have a progressive water/Methanol injection system since I cannot use an intercooler. I am using a Bowtie overdrives level three 700R4 to get the deeper first gear along with a 2400 stall lockup B&M Holeshot converter. Iím hoping this combo will get me in the 13s with my heavy 1981 TA and get reasonable mileage.
Ondatrack is offline   Reply With Quote
Old 01-14-10, 01:42AM   #2
turbo69BIRD
Moderator
 
turbo69BIRD's Avatar
 
Join Date: Feb 2005
Location: simsbury CT
Posts: 5,717
Default

I like it!

why not be different and try to find a better way to use cheap and plentiful stuff. I am sure all the 301 owners would appreciate a good running 301 making a name out there.
Youd be there hero for sure!

Think of all the shit those poor owners have taken over the years.
turbo69BIRD is offline   Reply With Quote
Old 01-14-10, 03:04AM   #3
twinturrbo406
Pontiholic
 
Join Date: Aug 2008
Location: ocoee florida
Posts: 726
Default Cool ....

Sounds like you are braving new territory, i commend you for that. Very interesting build you have going, keep us posted, any pics yet ?? Have you considered building an intake manifold for the 301 and run standard d-port heads ??? Would take some fabrication, but i bet it'd run much better, can't speak for the crank though....... but either way, very cool i think, i like bravery .......
twinturrbo406 is offline   Reply With Quote
Old 01-14-10, 05:21AM   #4
GET IT ON
Pontiholic
 
Join Date: Dec 2006
Location: Pacific, Missouri
Posts: 1,112
Default

First off, I like what you are doing. I do know the best turbo applications for higher power have a different duration flip, but who knows. I do have to ask what style dish is the ford piston? I wish that the aftermarket companies would copy almost the best dish ever designed, and thats what the 301 Turbo had to begin with. In piston design alone you will have a powerloss. Nothing you can do about it. But frankly the piston companies are too stupid (and yes, after talking many times with these guys, I can unfornately say that) but there might be2 or 3 that if allowed by their companies could do it. (but still not understanding why).

The only risky area i see is your rod journal on the crank. Did you get it nitrided after the grinding? Rockwell tested for hardness? I am assumming you did balance it to the enth degree. You may want to look into the 1.8 rockers for the sb ford also. Did you O-ring the block or heads? I would, regardless of gasket type.

I believe you will find a 2 7/8" i.d. downpipe to be better at a later date with the 3" exhaust. It was on an other wise stock 301 Turbo
You are in good shape with the stock distributor set up with an added aftermarket external coil and something along the lines of the Mallory version of msd's 6 a boost box.
I think you are going to have some fun with it. If your crank ever gives away, as long as the block is good enough to reuse, there is always longer stroke crank possibilities. Enjoy it and keep us updated on you progress.
GET IT ON is offline   Reply With Quote
Old 01-14-10, 10:04AM   #5
DocsTA
Turbo addict
 
DocsTA's Avatar
 
Join Date: Feb 2009
Location: USA
Posts: 1,146
Default

That is alot of work seemingly well laid out. It is good to see someone do a 301 turbo car. I have always had a like for them as my first car had a 301 non turbo that eventually had made its own AC, rod through the block.

I am looking at another 80 turbo with 19k miles that has been sitting in a garage for 20 years as the owner was in Prison. Needs a resto but it is in decent shape and all their. My summer daily driver. So I am interested in how it works out.
__________________




1979 Trans-Am Turbo Charged 535 IA2,
CV 1 heads with convertible exhaust option. 305cc, flowing 405cfm with mild intake port clean up


1979 Silver Anniversary 4 speed, numbers matching.
DocsTA is offline   Reply With Quote
Old 01-14-10, 07:29PM   #6
GREATGTO
Pontiac Nut
 
GREATGTO's Avatar
 
Join Date: Dec 2004
Location: DEBARY FLORIDA
Posts: 410
Default

Quote:
Originally Posted by DocsTA View Post
That is alot of work seemingly well laid out. It is good to see someone do a 301 turbo car. I have always had a like for them as my first car had a 301 non turbo that eventually had made its own AC, rod through the block.

I am looking at another 80 turbo with 19k miles that has been sitting in a garage for 20 years as the owner was in Prison. Needs a resto but it is in decent shape and all their. My summer daily driver. So I am interested in how it works out.
What was the guy in jail for, running beer from Texas to Atlanta Ga?
GREATGTO is offline   Reply With Quote
Old 01-14-10, 07:39PM   #7
marks73ta
Registered User
 
marks73ta's Avatar
 
Join Date: Feb 2006
Location: Glendale, AZ
Posts: 2,455
Default

Hey Ondatrack. Been following your posting over on 301garage. Good to see you over here. Been very interested in your project so keep everyone updated and go for it. Love to see how you come out. Mark L
marks73ta is offline   Reply With Quote
Old 01-14-10, 11:05PM   #8
DocsTA
Turbo addict
 
DocsTA's Avatar
 
Join Date: Feb 2009
Location: USA
Posts: 1,146
Default

Quote:
Originally Posted by GREATGTO View Post
What was the guy in jail for, running beer from Texas to Atlanta Ga?
Now that right there is funny!
__________________




1979 Trans-Am Turbo Charged 535 IA2,
CV 1 heads with convertible exhaust option. 305cc, flowing 405cfm with mild intake port clean up


1979 Silver Anniversary 4 speed, numbers matching.
DocsTA is offline   Reply With Quote
Old 01-14-10, 11:09PM   #9
twinturrbo406
Pontiholic
 
Join Date: Aug 2008
Location: ocoee florida
Posts: 726
Default Wow !!!

Quote:
Originally Posted by DocsTA View Post
Now that right there is funny!
Wow, they put the Bandit in PRISON for running beer ?????? SUMBITCH !!!!!!!
twinturrbo406 is offline   Reply With Quote
Old 01-14-10, 11:10PM   #10
Ondatrack
Registered User
 
Ondatrack's Avatar
 
Join Date: Jan 2008
Location: Hemet, CA
Posts: 9
Default

First of all thanks for all the kind words. When I went into this build I had no idea I would get so far into modifying the motor. I originally was just going to upgrade the exhaust on a 30k mile former 80s heavily modified show car but after my turbo blew a seal I decided to go for the bigger turbo while I was at it. It sort of snowballed from there like all my projects seem to do.
I had originally thought about swapping the heads as I have a dozen sets of traditional heads that I could choose from but the intake manifold modifications needed to use the stock turbo mounting location would have required fabrication skill I do not have and getting something like a sheet metal manifold fabricated was out of my budget. A couple of guys on the 301 Garage site have worked on modifying various manifolds for conversion to blow thru but I wanted to see what I could do with the original turbo design. I was pretty happy with the flow from the heads although it took a lot of work for me to get them there.
The crank actually has 2 inch rod journals to begin with and my low mileage crank was simply polished so I didnít need to have it nitrided. The dish on the Probe Ford pistons is actually more like a D shaped cup with the flat side not completely straight as it moves around the valve reliefs. There is a fair amount of flat quench area. These were a compromise as I didnít want to pay $700 plus for custom Ross or JE slugs. Mine were brand new from Probe that they sold cheap ($120 vs. $578 retail)due to them having .927 pins instead of the .912 that they were supposed to have. Everything was balanced thoroughly.
I didnít O ring the block as I felt that the MLS Cometis and studs would be OK for my levels of boost and the people I know that have used the MLS gaskets if the surfaces are prepped right have not seemed to have any issues at even higher boost levels, Iíll see I guess. I had the 1.65s lying around so I went with those to start but I may step up to the higher ratio if I feel I need more from the cam.

Tony O.
Ondatrack is offline   Reply With Quote
Old 01-14-10, 11:59PM   #11
Ventura541
Registered User
 
Join Date: Dec 2009
Location: Janesville Wisconsin
Posts: 59
Default

Just wondering how the webbing in a 301 compares to a standard 400 block.
Ventura541 is offline   Reply With Quote
Old 01-15-10, 07:08PM   #12
69GTO
Registered User
 
69GTO's Avatar
 
Join Date: Apr 2007
Location: Alftanes 225 ICELAND
Posts: 404
Default

I've always wanted to build a poncho from a 301 turbo block, using round ports, 3.75 stroke crank or less, short rods and custom intake etc.

Good luck!

PS. the turbo blocks are supposed to be stronger compared to the N/A 301 blocks.. I don't know how they compare to the early 400 blocks.. Tom S might know something about that deal.
__________________
69 GTO street car. 464 Pontiac, 88 singleturbo, 210XHD Rossler trans,
3.30 gears. 850 CSU carb, Tomahawk intake, stock block, factory N-crank
and ported 197 heads. 3650 Lbs with driver. Stock suspension.

9.25 best ET with 1.42 60
151 best mph
& 5.95/119 in the 1/8th
69GTO is offline   Reply With Quote
Old 01-15-10, 09:32PM   #13
marks73ta
Registered User
 
marks73ta's Avatar
 
Join Date: Feb 2006
Location: Glendale, AZ
Posts: 2,455
Default

From looking at them I would compare them to the last 400 thin web blocks. They also use drift pins in the mains to locate the caps versus dowls. For the short stroke of the 301 I believe the turbo block would be more than adequate. Mark L
marks73ta is offline   Reply With Quote
Old 01-18-10, 02:56PM   #14
Ventura541
Registered User
 
Join Date: Dec 2009
Location: Janesville Wisconsin
Posts: 59
Default

What bore can you take them to.Greg
Ventura541 is offline   Reply With Quote
Old 01-19-10, 12:54AM   #15
Johnny406
Retired Army Boy
 
Johnny406's Avatar
 
Join Date: Nov 2005
Location: Fountain Colorado
Posts: 493
Default

I always wondered how those siamese ports would tolerate more boost. From a guy who has a weird build himself, I LIKE IT!!
Did you bottom fill the block to help stiffen it up?
__________________
Johnny
78 T/A 463, Ultradyne custom cam, very ported Greg Merrick Heads, TH400, 3.31 12 bolt, 3425lbs


81 T/A 350 sbc vortec heads 4 speed 3.42 posi
Johnny406 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
My turbo build thread... Chris Petersen Forced Induction 62 08-03-14 04:00AM
Im bored, so I want to do another turbo build DocsTA " TURBO BUILDS " 68 01-06-10 01:04AM
who's gonna build the pontiac turbo stuff !!!!!!!! pontiac mike Engine Tech Discussion - Street or Strip 7 12-13-09 05:33PM
If you wanted to build a turbo? Bankbook Forced Induction 63 01-22-09 12:38AM
Turbo street 400 build up. Chris Petersen Forced Induction 5 03-10-08 08:28AM


All times are GMT -3. The time now is 10:16AM.

Featured Ads
Ken's Speed & Machine
Mayhem Turbocharging

Carter Cryogenics.  What can we freeze for you?

Pacific Performance Racing

Central Virginia Machine Service.  Home of the Injun Engine!

All Pontiac Engine Kits

Larry's Auto Machine.  Full serivce auto, marine machine shop, domestic and foreign.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
2001 - 2007 PontiacZone.com
Page generated in 0.13206 seconds with 43 queries