Father & Son Chevy Build Project

Y

yortdaddy

Member
My goal of a larger displacement small block with aftermarket block, forged bottom end and nice heads will have to sit on the back burner for another year or two. The shopping list I have put together just needs to stay a list while I ensure that my wife is able to successfully finish the schooling goals she has. I’m sure most on this board know the budget choices that have to be faced and this is one of those. p
Not to say I’m not going to build a motor… just not the one I had in mind, yet. I do have a 350 I picked up Saturday, it is already sitting on one of the stands in the shop and hope to play with it this spring. I know that it most likely has 906 heads on it and is caked with sludge. I will have to start pulling it apart and cleaning it to know the full extent of condition.
I’m away working remotely this week so I have had time to read some of many the build-ups of budget motors oriented around these heads and will try to apply what I have picked up from the various articles out there as well as the threads of data I’ve read around here.
Since I know everyone around appreciates pictures, I will attempt to document my (and my children’s) adventure building a little motor for our Camaro. It will be my first full rebuild and I plan on putting my two oldest kids to work assisting. Should be fairly easy to put a larger grin on our faces than the TBI motor has been able to… and it has made us all smile plenty.
 
Re: Hello There!

yes most of us are all too well aware of limited budgets and family needs, taking precedence over the hobby's wish list.
 
Re: Hello There!

Holy smokes… my last post was February? Wlle the kiddos have helped me tear down the donor motor… it was a royal mess. Heads have been to the shop to be tanked and checked… they checked out fine, no cracks! Block is at the shop now… they tanked it and checked it out... ready to move on to next steps.
Just thought I’d let you know we didn’t abandon the project.
 
Re: Hello There!

as always, posted pictures and more bits of detailed info would be great! :mrgreen:
 
Re: Hello There!

For sure... wasn't sure if this was the appropriate location for an attempted build thread or not... but I will at least see if I have one picture of the pudding filled motor we started with.

First build so we're keeping it simple and as budget minded as we can. Of course, we know we will all learn allot during the process. I’m trying not to ask my race car neighbors too many questions as they have a vastly different idea of budge than we do.
Quick synopsis:
350 roller block
Stock nodular iron crank
Forged pistons, looking for just shy of 10:1
Scat I-Beams with 7/16 cap screw
Vortec castings… will clean up exhaust and some other mild work

Still up in the air about cam selection. Original plan of just using the GM hot cam kit and cutting down the valve guides for the springs... but have an email chain with Comp Cams on some other options.
Converting from TBI to MPFI controlled with EBL and tuned with wideband.
This will be going in a Camaro that I would guestimate in the 3500# range, 700R4 with 3.73 gear going in. Once Car is running well with a solid tune we will be running a small shot of nitrous at the track for giggle factor.
 
Re: Hello There!

I'm sure that being as experienced with this hobby as a lot of you are.... you've seen much worse! The donor came out of my buddies z-71 hunting truck... lost an intake gasket and he didn't catch it until all his oil turned into jelly and never drained back into the pan. It sat for a few months and he just ordered a crate replacement for it... donated the old for our hobby/learning experience.
 

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Re: Hello There!

yortdaddy said:
For sure... wasn't sure if this was the appropriate location for an attempted build thread or not... but I will at least see if I have one picture of the pudding filled motor we started with.

I think most are in the section called "Engine Combos and Dynometer Database", but it's up to you. I thought about splitting the thread, but just couldn't figure out a good place to do that. :)


Still up in the air about cam selection. Original plan of just using the GM hot cam kit and cutting down the valve guides for the springs... but have an email chain with Comp Cams on some other options.

Why not post the cam specs or the part numbers, so we can see what your thinking.
Click to expand...

Wow that was dirty, but it's like waxing a car that doesn't need it, not very satisfying. You will/are much happier when it comes back after looking like it did !!! :D

 
Re: Hello There!

If splitting the thread is an option and throwing it in that section is a possibility… that would be fine with me… would make more sense anyhow. Maybe from the “ February 18th, 2014, 10:11 pm” post on?

Well the feedback I received from Comp support was a bit off… awaiting additional response. He recommended a hydraulic flat tapped stick so I had to re-iterate that I’m working with a factory hydraulic roller set up. We will see what he has to say about that.
Just plugging my known info into their online recommendation utility… of the selections it presents I tend to be attracted to part # 08-301-8. LSA 113* Intake Centerline 108*… I linked the part number to the specs page on Comp’s website.

Hyperlink in my text didn't work... here it is:http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=204&sb=2

I know the GM HOT Cam kit is a proven performer… and an easy order but we will adding additional power and I can’t help but suspect I will be wanting a bit more after it gets all tuned up.
We’re not in a huge hurry so we can take our time picking out the right stick… need get my pistons and rods ordered this weekend and am currently debating on just ordering a Scat rotator and grabbing a few extra cubes in the process. And I know Grumpy is a fan of matched sets like that.
 
a good machine shop should be able to either hot tank or heat and steam clean those heads and make them look far more presentable,
so they can be carefully inspected for damage and flaws, but you can get about 85% of the way to clean with a portable pressure washer, some solvent spray and some rifle bore brushes to clear and clean the oil passages one the old plugs are removed., obviously youll need new plugs and freeze plugs and cam bearings


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Thanks Grumpy! More reading for me tonight!

Neighbor did his best to talk me into the stroker kit... might have to do it... will decide in the next day or two.
 

With a stroker crankshaft in a stock block, it's likely you will need to grind
some clearance where the rods pass by the oil pan rails. How much of a
stroker are you considering?

Grumpy,

What do you give up when you have a camshaft designed for nitros, but
you are not using nitros?

Below is the cam that Yortdaddy posted a link to above.



 

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when you have 12 degrees more exhaust duration on a cam with a LSA of 113,its almost always designed for a SUPER CHARGER application, the object is to allow the increased volume of gasses generated by a super charger stuffing the cylinders ,cylinder pressure to blow down on the exhaust,with minimal overlap, to minimize exhaust scavenging, and to trap as much of the pressurized intake charged in the cylinder as you can, without having a great deal of that pressurized intake charge of fuel/air mix ,wash thru the cylinder during valve overlap, the result is a bit more power with a super charger but a bit less torque running N/A.
on a nitrous application , the extra exhaust duration helps cylinder scavenging , but the 113 LSA will not always produce the max results that a bit tighter 110 LSA might bring.

heres a similar cam that crane sells that works rather well matched with 1.6:1 ratio roller rockers if the engines using NITROUS rather than a supper charger
crane119831.png



heres the crane 119661 cam I,m using in my 383 with erson 1.6:1 roller rockers, but it requires a 3200 rpm stall converter speed and a 3.73:1 rear gear ratio to maximize results, and yes you darn sure know when you hit the WET nitrous TPI system with that cam
with the 175 hp shot of giggle gas I set it up for.
119661.jpg


http://www.jegs.com/i/NOS/741/05151/100 ... tId=749110
viewtopic.php?f=32&t=430
 

I don't understand how nitrous is like a super charger. I can see where a pressurized
intake passage would push the intake charge right out the exhaust during overlap,
but why does nitrous need more exhaust? It doesn't have a pressurized intake does it?

Nitrous is just oxygen rich allowing more fuel addition to the air streak than plain air.

 
I’m pretty flexible on stall speed for track use… but what I want to keep mindful of… I wish to retain the 700R4 for use of the OD gear and use of a lockout converter for highway/lean cruise mode. This in mind… anything more that part throttle, (I can program the variables as needed) could potentially take the ECM out of lean cruise and turn off the lockout to bring the power band back into play should it be needed for passing, showing off ect. I would think that with 3.73 rear gear behind that 700R4… in OD that would put my highway cruise in the 2-2.5K range… while I won’t be using it as a road trip vehicle much… I do plan on doing some “chase” duty as I follow Drag Week around.

With the Vortec head exhaust port design… I assumed that a bit more lift or duration on the exhaust would benefit the lower exhaust to intake flow ratio that these tend to content with. But I trust your experience a lot more than the feedback I’m getting from the emails from “tech support”. Hopefully tomorrow he will have something more insightful to provide me and I can compare against these two. I will probably contact a few more manufactures before I decide. It’s lower in the priority list at this moment that the piston/rod debate I’m having.

Looking at a few 383 rotating assemblies… but my brain keeps playing the game of “if you buy that then you might as well pony up a few more bucks for this” and before you know it the budge starts changing dramatically and I lose sight of the term “cheap build.” I may very well decide that I need to find some middle ground. To make matters more complicated I was listening to a list of all the benefits of boost from my neighbor buddy last night… he is a bad influence on my decision making.

So this week I have to sit down… take a hard look at some numbers and make a choice or twelve in order to get this ship moving.
 
Grumpy, that crane 119661 that you're using... I see if says "fair idle"... but that is somewhat subjective to the individual to judge what is and is not fair... I'm curious as to how well it holds vacuum at lower RPM for the use of power brakes and such... pretty manageable? I have no problems with a nice choppy, health sound but I don't want to end up being that guy who has a cam that drives him looking for solutions to solve other problems caused by "over-caming" You know what I mean?
 
yortdaddy
the first and smaller cam is about as large as youll want if your concerned with power brakes working as if the cars 100% stock, and even with that youll notice some difference the larger duration crane cam 119661 I,m using is marginal in many ways, if you want to have a car operate as if its stock, in fact I ran a Crower 00471 which is just a bit larger for awhile and while the peak power was better the heavy corvette, I used it in made it less than ideal.


[b:3ksp4le9][color=#FF0000:3ksp4le9]Indycars[/color][/b] said:

I don't understand how nitrous is like a super charger. I can see where a pressurized
intake passage would push the intake charge right out the exhaust during overlap,
but why does nitrous need more exhaust? It doesn't have a pressurized intake does it?

Nitrous is just oxygen rich allowing more fuel addition to the air streak than plain air.
Click to expand...

ADDING NITROUS
(ITS SIMPLY ADDING A GREAT DEAL MORE OXYGEN CONTENT TO THE AVAILABLE AIR , in THE CYLINDER ALLOWING YOU TO BURN MORE FUEL EFFECTIVELY THUS PRODUCE MORE CYLINDER PRESSURE OVER THE PISTON< RESULTING IN MORE TORQUE)
ITS use developed similar INCREASED exhaust pressure and INCREASED VOLUMES of exhaust gases, similar too what results in a super charged application, because atmospheric air,run in a N/A engine holds about 21% oxygen and you run a fuel air ratio about 12.6 pounds of air for every pound of gasoline.
with nitrous ADDED theres, up too, about 40% oxygen content available in the same volume of air as you would have with a supercharger at about 15 psi of boost, but without the intake being pressurized and with out the heat and weight a supercharger has, in fact nitrous is injected and radically cools the intake charge making it denser,so to maintain that similar 12.6:1 fuel air ratio your forced to be adding and burning a good deal more fuel,(obviously depending on the percentage of nitrous added to the outside air the engine ingests, vs pure nitrous and fuel which would require a bit more that twice as much fuel to maintain the ideal fuel/air ratio that extra fuel being burnt is where your getting the extra power nitrous used generates, thus the extra exhaust gas volume, you might want to think of nitrous as generating up to twice the volume of exhaust gases from about the same intake volume, thats running and burning extra fuel to generate higher cylinder pressures,up too, twice the oxygen content, means up to twice the fuel being burnt per compression,power and exhaust stroke. thats one reason nitrous cams tend to have, and work better with longer exhaust duration to help blow down the cylinder pressure and volume, but don,t require as wide a LSA as a super charger cam, because they don,t require you trap pressurized intake charge air from exiting the exhaust during valve overlap to the same degree, a supercharger application would benefit from.
pistonposition2.jpg


powra1.gif


LOOK AT THESE TWO DYNO GRAPHS

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Chevrolet-Corvette-Dyno.jpg



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Several factors came into play… but we decided to stick with factory displacement. We, (mostly I) know that mistakes are most likely to happen with our first build… so as far as a long block we will keep this one very close to stock and focus on the top end of the motor including the EFI changes. So 350cid it is for us!
On another note… the support guy from Comp sent me the following response this morning:

“Thanks for the extra info, there is a cam kit that fits your goals perfectly. The cam kit 08-467-8 is a great match for your specs. This cam will help make nice power/torque, great response, will have a great lumpy idle, and should work well with NOS. The cam is 230/236 @ .050 and the lift is .576/.570 on a 113 LSA”

http://www.compcams.com/Company/CC/cam- ... d=204&sb=2

To me… the closer intake to exhaust duration numbers would be preferred over the initial cam I posted… peak lift is a bit higher than I had thought it would be but I guess with the numbers reflecting that of a 1.6:1 rocker that makes sense… and with a bit shorter duration than the first stick Grumpy spoke of… LSA of 113*… fair street manners? With the gear and stall to accompany of course.
I need to re-read all those cam theory threads as every time I think I am close to getting it straight in my head, I start second guessing what I thought I understood. Or my son asks a question and I can see myself with the deer in the headlights look. “We will worry about that when we get to it” was my last response :lol:
 

I was reading thru the thread again and notice you are expecting a cruise
RPM of 2000-2500. You might find this info helpful.

RPM at 70 MPH
viewtopic.php?f=99&t=3355

Also this might help you keep up with budget/machine shop costs.

Spreadsheet For Tracking Your Machine Shop Costs
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The above and many other Excel spreadsheets are in this section.

spread sheets and engine related forms
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If you plan on using Nitrous oxide as a power adder its a good idea to use a Ductile. iron Top ring set with a Moly plasma face coating.
Rebuild the Vortec heads with full length Bronze silucon guides. Viton valvestem seals on Intake & exhaust.
Use a Premium set of Set of Ferrea or Manley Pro Flow style stainless steel valves.
Hypertenutic pistons ok with a 100-125 HP Shot.

Forged pustons more ideak for Nitrous use.
 
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