merlot566jka

So the engine ate the throttle body airfoil screw. One piston is toast, and one head may be too. I have decided to rebuild it. But I want some other insight.
I decided I want to stay at 350ish CID. Reason: Cost, and RPM.
I like to rev the **** out of it. Just think it sounds wonderful all wound up with my ARH headers and Corsa's. And staying away from the 383/396 realm saves me from buying a crank, rods, and extra machine costs and time.

So let’s lay it out:

Pistons:
Rings:
Port Work:
Cam:
Bearings:
Gaskets:
Clutch:

Budget: $3300
Assembly and installation by yours truly.
Objective, Radical enough to hear a lope at idle, with ability to hop in and drive away anytime, without stalling at stop lights or forking over my paycheck in fuel costs.
Power goal: 400rwhp

Supporting mods already installed:
ARH 3/4 primary long tubes
3" exhaust
C5 Corsa Indy Pace Muffs
Cut air lid w/ K&N
4:10's
Hurst Shifter
Bosch 3 32lb injectors
PCM4Less tune
MSD optispark
MSD wires
MSD Coil

So how would you build it staying within the $3300 and 400rwhp limitation/goal?

rklessdriver

Couple of things before I go into detail.

There is alot missing in your list so I did my best to fill in the blanks. Alot depends on how bad the damage from that bolt is. If the block has a cracked cyl, then you got to put a sleeve in it and thats more $$$. If the crank needs to be turned thats another $150. What about the timing chain?? LT4 ED is one expensive SOB.... Double roller is only 84.00 (Cloyes 9-345X9) but you need an elect WP.....

These parts I'm recomending are good quality stuff & still budget minded. Your goal of no machine work on the block.... Not wanting to bore the block is BS.... used cyls are not straight and do not seal. Your call but I wouldn't build a motor to have it blowing oil out the rocker covers every time I drive it..... Balancing is also needed. I've got the ABSOLUTE minimum for you to get get by with listed.

The cam I spec'd is going to make peak power at 6500RPM and will turn 7K easily.... Power is going to hit like gang busters at 35-3800RPM. I'm not a fan of the stock PM rods turning 7K ALL THE TIME - So I'd be careful about how hard you buzz it on the gear change when playing around on the street. Keep it out of the rev-limiter/fuel cut off or I can guarantee it's going to spit a rod out.

$450 Pistons: Probe SRS 12334-030
$120 Rings: Perfect Circle PN 315-0036
$1895 Port Work: Advanced Induction CNC 195cc
$325 Cam: Jones (276/280 - 230/234 - .576/.576 108/112)
$55 Bearings: King Rod (CR807) & Mains (MB557). Durabond Cam (CHP8).
$81 Gaskets: Fel Pro CS9966, Victor Reinz 5898, Fel Pro MS99580
Clutch: Depends on which FW and a used/abused DM isn't going to last long with this kind of power......

Machine work: Prices vary by location but these are what my shop charges.
$75 Clean block
$200 Bore & Hone w/plate
$80 Press pistons/install new
$150 Balance rotating assy (no Heavy Metal - HM = $50 per slug)
$ Repair damage to cyl head (depends on how bad AI says the damage is)

I'm at $3400 with no clutch and no idea how much AI is going to charge you to weld up that head.... Not to mention no timing chain and hopefully no cracked cyls or bashed crank journals....

My parts prices are mail order like you get from CNC-Motorsports or Competition Products. I gave you all the part numbers so you could do some searching for the absolute cheapest price from the cut rate guys on ebay but I don't know how much you could knock off.
Will

merlot566jka

Will,

I forgot to mention a few things...

I want to go .030 over... Thats a no brainer, who builds an engine and doesnt bore it?

Balancing... same deal. wouldnt consider not doing it.

I was trying to aviod EXTRA machining costs... over what it normally takes during a rebuild...

Totally forgot abotu the Timing Chain... crap. The oem is expensive?

The cylinder liner is fine. Not even scored. The screw was in there for about 45 seconds at idle when the car was shut down. Damage is minimal considering the fact there was a screw in the engine.

The head is beaten, but wont need to be welded. Has a bent valve and looks like it was beaten with a meatcleaver...


Tell me more about this cam... Is that .576 w/ 1.6 rockers?
Springs?

You like AI over LE? LE has those packages, that come with a cam and all the head work...

I wont be spinning 7k all the time. I like to spin it up now and again... but its not a race car.

Clutch, I wanted to go with a lighter FW and get a clutch that will hold the power... I have heard the "rocks in a can" noise in person on anothers car... not as bad as some make it out to be.



Have to work, will check responses tonight.

Thanks!

merlot566jka

Looking on summit at my lunch break... any reason you recomended Gen1 pistons?

I found this, and it looks adequate... Certainly cheap

http://www.summitracing.com/parts/FE...n/?prefilter=1

mtwoolford

how about rods ? no one seems to have a great opinion of the original powdered metal rods or their ability to be resized/rebuilt? and if new rods are in the picture,why not 6 inch rods and matching pistons ?

cv67

pm rods are ok but think what will is saying if youre going to buzz it to 65-7k you need to upgrade.

rklessdriver

You'd be surprised what people tell me they want to build and then don't want to spend $200 to bore the block....

Balancing is important. With those Probe pistons I recomended, they are so much lighter than the factory stuff that you'll be overbalanced by about 10%.... If you buy those Speed Pro's you'll be underbalanced by at least the same amount.... In both cases it would be hard on main brgs.

Yes. The LT4 ED timing set is almost $400.

The pistons I recomended are a Sportsman class racing piston. Perfect for Bracket cars, limited class oval track cars and very hot street cars. They use 1/16 compression rings and 3/16 oil ring. They are Strong as Probe uses a 2618 alloy and they are light weight.

The rings I recomended are file fit. You grind them and set the gap where it is perect.

The L2256 pistons in that SP kit are actually GEN 1 with 5/64 compression rings..... There is a good bit of HP lost with 5/64 rings. Not to mention cyl wall wear is far worse. They are not even as good as the stock LT4 pistons as far as HP goes because of the rings (Stock LT4 has 1.5mm rings). They are stronger as they are forged (VMS 75 Alloy) but they weigh a TON and are harder on the rods for higher RPM use..... That piston is the same as the old TRW flat top and it's a 40yr old design....

Basically the rest of that SP kit is a stock rebuild. Stock rings, Stock brgs, stock thick head gaskets....

The part numbers I gave you, IMO the cheapest/best way to optimize the stock bottom end for performance use. There is a huge difference in the level of quality between my recomendations and that "kit".

The cam. Mike Jones has been my only cam grinder since 2009. Before that I used Reed and Howards. I have one of Mikes cams in my personal 92. It's the first cam I ever bought from him and I bought it to see how good his stuff was. It has not disapointed.

Alot of our business is freshening up and updating customer engines every year during the off season. Everything I've bought from him has picked up the engines we were able to change over to his stuff.

About the cam specs. Yes the .576 lift is with 1.6 rockers.

AI sells cams (Comp) and LE sells cams (Bullet). Nothing against them but if I didn't think my recomendation was better for what you are trying to do - I'd just let you pay AI $400 for their cam..... If you want to buy their package no problem, it runs fine.

You'll need to tell AI what the recomendation from Mike about the spring pessure is - but all that work from AI for $1895 comes with new valves and springs.

I do prefer AI over LE.... There is a fellow on this board that I help out and he has had nothing but problems with is heads from LE. There are a few other claims of the same kind of problems.... Look I've been building racing engines for my whole life. I know how racers are.... Most of Llyods work is good to go and makes good power but even comparing his best LT4 port - The AI heads are a better product IMO.

Another great option is the AFR 195 Street. They have the advantage of being brand new heads and you can sell your LT4 castings..... I can give you the info for a guy here on the board who will cut you a great deal on a set. The AFR 819 valve springs will run that cam fine as well.

I agree with you on the tranny noise not being that bad. I have a Fidanza Alum FW and SPEC clutch. If you want to go single mass, I think the steel FW would be better as it's a tad heavier and will make the car easier to launch (with traction) and smooth out the power hit on the street with your 4.10 gear.

I would recomend a SPEC Stage 2 for your car. I'm personally sold on SPEC's clutches. I know there are haters out there and plenty of reported problems with their stuff from afew yrs back - All I can do is go off my direct experience. I've put my stuff thru crazy abuse and it keeps on trucking. I recomend SPEC to everyone I build engines for or do consulting for.... None of them have had a failure either.
Will

rklessdriver

I would love to use some 6" rods and lighter pistons. It's great up grade that will give him some added meaure of security..... I tried but I just couldn't do it in his budget. The Eagle SIR or Scat (3/8 cap screws) are right about $220....

With light pistons the PM rods will survive 6500RPM and blast up to 7K when he's racing - As long as he keeps it off the rev limiter.
Will

87bob

If you do a web search using the title of this response you will find a web page that gives you the actual part numbers that differs from each other. Im traveling so I don't have it with me. If you can't find it let me know and I'll send send it to you this week end.

I am doing the same thing. I am buying a used LT-1 and I am going to build it to the LT-4specs. There is a good article in an (don't quote me) old SuperChevy or Chevy High Performance magazine. Which goes through this. Again I don't have it with me but it should pop up if you do an Internet search. Let me know if you need these bits of info. The magazine article references a top end kit from Performance Warehouse of heads (AFR's) intake (Edlebrock) a cam. The crank, pistons and rods differ. Let's keep each other posted on progress. I'm picking my LT-1 this weekend I hope.
Here is where you can find the specs for both engines.
http://www.grandsportregistry.com/lt1vslt4.htm

cv67

Will

http://forums.corvetteforum.com/c4-p...-for-sale.html

These pistons I think are around 420g not sure on the pin.
Something that may work for him?
Crank is a 2 pc rms though

rklessdriver

I thought hard about linking him to your FS thread. Your rods and pistons would be perfect, but I didn't think you want to split them from the crank.... if you did not sure what you'd want for them.

Manley is definatly a step up (and then some) from Probe and Eagle.
Will

littlesk8cracker

you said in post 1 you wanted to stay at 350, but in post 3 you said you wanted to bore it .30 over. you know that would make it a 383?

96GS#007

Actually it makes it a 355. If he increases the stroke by adding the right crankshaft....then he can get it to 383. Of course then he will also need different pistons than what Will has spec'ed.

merlot566jka

No sir, that's a 355
96 gs007 has it right.

420g pistons? with pin and rings? I gotta see this!

87 bob, I know the differences of the lt4 and lt1... and I have an lt4 already...

Will,
Yikes, that stock timing set is a bit spendy. Why so much?

Pistons: I am looking at the pistons you suggested... I like the idea of lighter pistons for sure... I understand quality difference... but why does it say gen1, and whats the difference from gen1 to gen2? Did they move the pin?
I was under the impression that lighter pistons = less rev stress. I have that crazy formula in my mind about piston velocity...6700 fpm at 7k rpm... add 580g per piston, were talking some serious load here. Lighter pistons sound like a damn good idea

As far as that kit, I just got the first .030 forged kit I could find on summit within mins of searching... Just looked at the price and wondered why so cheap. Bad idea.

Heads: so AI will take my lt4 heads and do them over and they will flow close to an afr 195? And they will put in springs that spec to Mike Jones' cam? All for around $1900?
( I would like to keep my LT4 heads)

Cam: Mikes cam.... sounds good, lopey looking. 112 lsa? Is that going to give me some surge at idle with that duration? Where can I find more info on this cam... like a dyno graph or anything?

You say steel FW instead of alum? I assume for street manners and off stoplight driving... I thought alum would help the launch control (ie reduce torque impact on launch) Either way, I think steel is a better option for drivability... but that alum FW sure would revv fast.

SPEC stage 2, go it. I was looking at their stuff recently, never got farther than price and availability.

Other things that crossed my mind today...
Tuning
Fuel pump
Injectors
Plugs

And is this combo Nitrous friendly? Not that I have nitrous in the budget... but maybe later.

Thanks a million guys. You are really helping me on time... researching this could turn into weeks without some direction.

cv67

Gen 1 just means the crank (being a 2 pc rms) rest fits any sbc ever made.

Less piston weight means less pulling force on the rod bolts/caps

Good luck in the hunt, putting something together is always fun

87bob

Sorry you asked for help and did not specify how much you knew. I won't offer any more suggestions!

merlot566jka

Ah, gotcha.

Thanks!

96GS#007

Stock injectors will be fine if you do the following...

- Bump the fuel pressure to ~50psi vs the stock ~43psi.
- Calculate the new injector flow rate (it'll be right around 31# @ 50psi vs the rating of 28# @ 43psi)
- Adjust the tune to reflect the new injector sizing

Stock fuel pump should be fine unless you decide to add NO2

Plugs...I'd go one step colder

Tuning...it'll definitely need a tune for the cam change, displacement change, injector flow, heads, etc. All areas of the tune will need adjustment: idle, part throttle, and WOT. Will it run and drive with the stock tune? Yes, but street manners will not be as good and you'll easily leave 20-30 hp on the table.

merlot566jka

Sorry if I came across harsh Bob, I know its a bit hard to communicate electronically. I know a bunch, built a few engines, been around for a little while.

96gs007, So just use an AFPR, and bump it up? Thats the easy way! I have the bosch 3 injectors, Ill have to run the PN, but for some reason I think they are designed to run at 60psi. Not sure.

One step colder plugs, Check.

Sidney004

A lot of great info for a budget minded build(like the one I plan to do, when mine gives up the ghost!)