Hello, I have never built an engine before but want to do this for the experience. This post will be quite long so hang in there.

This engine will be built over time by buying the parts as i get the money. This is not another build my engine for me post, but i will outline what i have come up with for parts so i can get input on any potential problems you guys may see, or suggestions for what might work better.

The goal of this motor is a fun 355 for my weekend driven 91 camaro rs, that will see the dragstrip 2-3 times a year. A goal from anywhere to 350-400 flywheel horspower would be great.

To start off i already have a 4 bolt main 1 piece rear main seal block. Casting number 14093638. This block will clean up nicley at .30 over so that is the reason for the 355.

Bottom end:
I have the crank, rods, and pistons from this engine block but not sure if i should use them. Obvously the pistons are a no go with the 30 over block, but the crank would need to be machined, and rods rebuilt.

I1. f i go new parts, Scat 9000 nodular iron crank, Scat 4340 I beam rods with ARP screws, and pressed fit wrist pin.

2. Pistons - KB 30 over hypereutectic 12cc dish, with a listed 9.6-1 CR

3. Clevite main and rod bearings. Would the H series be what i need?

4. Speed pro moly file fit rings 5/64 5/64 3/16 widths

5. Oil pump, pick up, and pan Not sure what to use

6. balancer not sure, can i use the stock 305?

TOP END

1. GM Upgraded Vortech Iron Heads for .525" lift, 1.94-1.50 valves, fully assembled...64 cc chambers, 170cc intake port, streight plugs

2. Valve covers, I would need center bolt style correct?

3. Edelbrock Performer RPM Air Gap Intake Manifold dual plane

4. Cam - Magnum 280H 230/230 duration 480 lift 110 LSA RPM Range 2,000-6,000
Magnum 292H 292/292 duaration 501 lift 110 LSA RPM Range 2,500- 6,500
- I have a 700R4 auto trans, would be using anywhere from 2500 -3000 stall converter depending on cam choice, and 3.73 rear gears

5. GMPP stamped steel 1.5 rocker arms

6. GMPP standard length push rods 5/16" diameter

7. Fedral Mogul Hi rev lifter

8. Scoggin Dickey Pro series double timing chain

9. Holley double pumper 750 carb
-manual choke, power valve blowout protection, mechanical secondaries

IGNITION

1. Stock 305 starter ok or do i need to buy an upgraded one?

2. MSD 6AL, HP w/ rev limiter

3. MSD Blaster 2 coil

4. MSD 8.5mm plug wires

5. MSD Billet Distributor non computer controlled

 

if u end up getting a new crank/ rods upgrade to a 383, its cheap and it will make lots more torque and be fun to drive, you could also then usea bigger cam and keep it streetable

 

VERY poor cam and valve train choice.

1. You have a roller block, but the cam isn't a roller.

2. Vortec heads have all this TERRIFIC intake flow, but typical sucky stock-head exhaust flow. Therefore, they work MUCH better with a dual-pattern cam.

3. Those valve springs are barely better than stock.

4. Those rockers are just yerbasic stamped flexible rubber.


I'd suggest a Comp XR276HR.

For springs, look at either "beehive" springs, or step up to 1.45" double springs that allow .550" or more (if for no other reason, to allow for later cam upgrades); and look for 125-140 lbs on the seat, and 300-325 open.

Use AT LEAST the Comp 1400 series rockers. Ideally, use steel, NOT ALUMINUM, full roller ones, either Crower or Comp.

Your stock oil pan is fine.

Make sure your deck clearance (how far "down in the hole" the pistons are at TDC) is less than .010", preferably .000" (level with the deck). This will almost certainly require machine work; stock, that figure is .025" give or take (mostly give) a few, and many replacement pistons add .020" to that, meaning the pistons may fail to reach the top of the cyl by .045" or so. Use a standard .039" head gasket.

 

thank you for the response. I used moretec for information on the block. It says for this casting number roller or flat tappet cam. This block was supposed to have been out of truck so i thought it would be flat tappet. By looking at the block the lifter bosses would be taller if it is set up for a roller cam correct?

Thanks for the info on the vortecs, exhaust side. I will look into some dual pattern cams.

I have not purchased any of these parts yet. I want to be exactly sure of the build before i go out and start buying parts.

Thanks again, Andrew
----------
1989 truck block to be exact.

 

KB pistons are pretty expensive from what i've seen. I'd rather use Speed pro flat top hypers at around $90 a set, rather than the $200+ ones you've listed.

For some reason I think Vortec heads need self aligning rockers, ie I don't think they use pushrod slots. Double check this, but you may need guideplates, or self aligning rockers.

I'd use summit brand aluminum bearings, $12 a set is hard to beat. "High performance" bearings ie full groove or the like, aren't what you need.

The rest of the suggestions you've seen here are good, i'd follow those ideas.

It's good of you to post up BEFORE you bought the parts. You're less inclined to run them anyway. Good choice.

 

The block has the roller provisions cast in, even though truck motors almost always had flat tappet cams in them. At worst, they're not drilled & tapped. But they usually are. All you have to do, is get the roller stuff, and stick it in there.

There are 3 machining steps that are applied to the casting to finish it for a roller cam. YOu can look at your block and see if they're there. The top of the lifter bores should be machined off flat; the 3 bosses on top of the cam bearing tunnel will be drilled & tapped; and the 2 retainer plate holes in the front of the block will be D&T.

 

I would ditch the SCAT components, eagle builds better stuff IMO.

Heres my list for your bottom end

Eagle cast steel crank $200
Eagle 4340 Capscrew rods $215
KB Forged pistons $350

There is alot to do with rod ratio as well (this im sure is gonna start some cool posts) I say do the 6.125 ratio rods. Why? Because "You want the longest rods possible" Smokey Yunik (aka the guy who pioneered the SBC).

$.02

 

I'd shoot for a tad more compression, like 10:1 ish. Make sure that the block is zero decked and your overall quench is around .040.

 

i understand the rod ratio equations, but keep in mind for this build there is a little bit of a budget mindset. Im not doing a junkyard build, but trying to keep the cost down in some areas while still achieving my goal of 350'sh horsepower.
----------
is 10.1 ok to run on 93 with iron heads. I was thinking more around 9.5 -1 would be good for pump gas.
----------
thank you for the suggestions on bearings and speed pro pistons. I wouldnt mind saving $150 here and there.

 

I do believe it is, the vortecs have a great combustion chamber and don't like much more timing than 32-34. Keep in mind, higher compression with a good quench is more detonation resistant than lower compression with a wide quench.

I wouldn't be concerned about rod ratio, I'd save the money on the long rods and special pistons and put it into the heads or valvetrain, you'll make more power than with worse heads and a "good" rod ratio.

 

exactly i have no intentions of going longer then a 5.70" rod on this build

 

I agree with the above. However I would keep the stock crankshaft and put that money into the valve train. Regarding the Vortec heads the beehive valve spring upgrade to the stock Vortec heads is a good one. So It will automatically give you .550" lift plus all the benefits of the beehive springs.

By all means go with a roller camshaft. Go to the better rocker arms as has been suggested.

 

i will look into the machining costs involved with the stock crankshaft. I was just thinking that if it was too much the scat crank i mentioned is only $189 brand new so it might not be worth it to use the stock crank. Then i will need undersized bearings as well right? Are those more expensive then the normal bearings?

 

Nope, oversize bearings are the same price.

If machining your crank costs even close to the price of a new crank, get a new crank. Then might as well get the 383 crank, it's the same price.
You just need 383 specific pistons, which again, are virtually the same price.
The only thing different is you'll need to get a larger chamber in the heads, and or bigger dished pistons. Your call on that.

 

sorry meant oversize bearings, not undersize...was typing while on the phone

 

Smokey Yunick was building engines for race cars with a nearly unlimited budget. (And Cole and Duntov probably had far more to do with "pioneering" the small block than anything Yunick did) For a street engine there's no benefit realized for the increase in cost, and the longetivity of the engine actually suffers. A 5.7" rod will be fine.

 

Sure, a 5.7" rod will be fine. But the cost increase to use 6.0" is miniscule at best. If in a street engine the benefit is minimal, why do 383 kits almost always use a 5.7" rod vs. the 5.5whatever length rod that 400 cranks came with stock?

 

www.speedwaymotors.com

Nice economy rotating assys for $375. Your welcome.

 

There's more difference between a 5.565" rod and a 5.7" rod than there is between a 5.7" rod and a 6" rod, and the market for 5.7" rods is enormous, while the 5.565" rod market is limited.

There's nothing wrong with using a 6" rod, it's just not necessary. Pistons for a 350 with a 6" rod tend to be somewhat harder to find and are intended more for performance use, both of which make them usually more expensive. Compare the price of a Speed-Pro H345 at about $12 ea. with something for a 6" rod, which usually start around $40 ea.

Or on the link just posted above, they offer only one 6" rod kit for $459.95, compared to $369.95 for any of several 5.7" rod kits.

 

The reason that the 383 kits use a longer rod, is so that the crank can be internally balanced without the use of Mallory metal. NOT anything to do with making more power or any of that.

The penalty for the longer rod is having the rings compressed together, thinner, and sometimes even over the top of the pin. Thinner can be a good thing (lightweight) or bad (poorer longevity).

 

Pistons and rings are oversize. Bearings are undersize.

 

Good eyes! Oops.

 

thank you

 

Ok guys, camshaft choices are as follows

XR276HR-10

XR282HR-10

XE274H

XE268H

Looking for opinions on what would be better and why. I would like people to know i have a cam at idle but not sacrifice driveability.

Also on comps web site they reccomend sporings for each of those cams. Is that a good idea to follow there reccomendation or are there better choices on the market?

 

The last two aren't rollers, skip those. You're in the right ballpark though.

The comp XR276HR-10 with Vortec heads on a 350 is a PROVEN 375-400HP combo right there. It's a common setup. FYI that's very similar to the xe268h, but a roller. The xe268H with vortecs is the proven 375HP combo, so you'd be just a smidge above that.

While your machinist has your block, make sure it's set up right to use a factory roller cam setup. Ask him to look at it and be sure, or do the finishing machining touches to be sure it is. Then give'r.

Get JY roller lifters, they're all pretty similar, just find ones that aren't trashed.
You'll want roller cam springs, 1.43" OD generally, or beehives that would mean you don't need machining done on your heads. Your call. Look at what comp says is their "premium" choice. I'd take that suggestion to the bank.

 

thanks sonix, and thanks for the patients with the thread. I didnt know if the last two were roller or not. The comp web site just said hydraulic so i didnt know. At least i am getting a better idea of the build now. This board is great, i am really learning alot!

 

how about some crane hydraulic roller lifters?