So I finally have a job, it doesn't pay much but my bills are low. This means I can finally pull the tarp off my Trans Am and start building it.My dad drove it for a week without oil pressure and killed the rings and bearings, so I wonder, why rebuild the 305, why not drop a 350 in? I'm planning a big build, price is no problem, only time. I've decided I want a weekend streat beast. Pure low end torque and power. I've picked out a set of cylinder heads and a cam shaft that would give me low end power and I was wondering how well they would work together. I don't want detonation and I don't want it overcammed. I decided to go for a tight LSA of 108 degrees at 226 int 234 ext durations (at 0.050) on a retro-fit hydraulic roller cam and I've decided to go with a 64cc combustion chamber with 230cc intake flow, 2.080 intake and 1.600 exhaust valves. Another thing that's worrying me is that the only cam within the ranges I want has a 0.525 intake and 0.532 exhaust lift (with factory rocker arm ratio). Is this lift too big? Would my valves hit the pistons? I assume that's at a 1.5 to 1 rocker arm ratio making 0.35 intake and 0.355 exhaust lift on the cam. Should I run a higher rocker arm ratio?

I have a bare block 350 2 bolt main 010 block from a 1978 Camaro. It has absolutely no ridge, no cracks, no damage. Makes me think that it was pulled as soon as the car was brought home from the dealer and something bigger thrown in because it came with only 185hp. It has the normal brown tinge of light surface rust. I was going to get it cleaned and splayed.

Here's the links to the parts:
http://www.summitracing.com/parts/HRS-110325-08/
http://www.summitracing.com/parts/DRT-11710040P/

Thoughts, ideas, advice. All is welcome. Thank you.

 

Eh... your cam is kinda big for a street car.

You want unmatched cheap power? How does 400+ horses and 500+ ft lbs sound?

http://www.chevyhiperformance.com/te...que/index.html
You can replicate this even cheaper then the $4500 they claim; if you look hard enough you can find the block for about $150 and you can get a rotating assembly that will handle the power for about a grand. Don't worry about the extra 6 cubic inches. Fully assembled you should be in about $3500.

If you insist on using the 350 you can do something like this for $2600:
http://www.hotrod.com/techarticles/e...ild/index.html

I've been meaning to replicate their 406, I had the block and rotating assembly but sold it all to save up money for a LS1 TA.

 

As this is my first in-depth build, and not just throwing an engine together, I've really done a lot of research to find out how I should get my cam. I thought I picked a nice one with a lower duration for more low to mid range power? This isn't going to be a daily driver or anything, I got my truck for that, this is going to be something I can take to the strip on weekends or just tear up the streets around the city. I did look into making a 383 and making a 400. I found my 350 bare block for $25 so I jumped on it and decided to stick with a 350 because you can still get a lot of power out of them without having to bore them out. If something goes wrong with it in the future, or if it gets a lot of miles on it, I can always tear it down, bore it, and stroke it.

 

If I was worried about building power out of a budget, here's a Vortec 350 build. $3500 and 447hp.

http://www.popularhotrodding.com/eng...ock/index.html

But then, the 406 build you post claims lots of torque at low rpms, much more than this^ build.

 

If those numbers on that 406 are true, that thing behind a set of drag radials and 3.73's should sink into the high 11's or very low 12's and blow the doors off everything from light to light.

 

Okay, so after doing a little more research, the cam I posted earlier would give me good power at around 4K rpms.

Would this one be better for low end power?

http://www.summitracing.com/parts/CRN-104204/

 

That might be a low amount of lift (0.256 before rocker ratio). Should I opt for 1.7 rockers with that cam?

 

Does your block even accept a roller cam?

 

It's a retro-fit cam. Summit says it's made for my engine at my year.

Damnit, the new cam doesn't work for my year. Great, thanks for pointing that out. But the first cam listed fits it.

 

You can save some bux by using the GM V6 hr roller lifter outta the 3.8-4.3


http://forums.corvetteforum.com/c3-t...yle-350-a.html

 

It might be a good idea, but I'm not sure if those stock lifters will hold the power I'll be putting in this. I'd rather not try to be cheap, when you buy cheap things they tend to break easier. Also, I used to hear all the time how those lifters in the 4.3s would collapse and cause fuel problems. Thank you for imput though.

 

230cc heads on a 350 are not low end power capable. Run 200cc max, dart pro 1 comes in that size so if you want dart, run 200cc version. Cam is fine..it should be streetable and make good overall power through out rpm range of 3000-6500. gear it to match and throw in a 3200 stall and it should work out well. I'd go abit more like 3600 for best performance for a street/strip weekend warrior. I know guys running similar cams in 350 LT1 and a 383 sbc setup and they are both strong cars...trap 115mph and run mid high 11's. Cam can get it done but I'd like to see abit more lift.

Should have plenty of PTV clearance. Look at the lunati voodoo 227/233 cams with a 1.6 rocker. I think they have a retro grind in that range.

what intake manifold setup will you run? Carb or EFI?

another thing, i dont know if that howards cam is correct. advertised at 258 and has 226 deg duration at .050? thats a HELL of a steep lobe, very aggressive. I wonder what lift they measure advertised...as most 224-226 deg cams at .050" are closer to 270-276 advertised.

 

The intake ports on the heads you listed are far too large to make low-end torque.
The first cam you listed is too large.
The second cam you listed is too small.

All I can tell about your car is that it's an automatic and you seem to want low-end power from it.
If you're sticking with 350 cubes and a streetable automatic trans, then I'd suggest a head with around 180cc, but good flow numbers.

This camshaft works well for low-end power and retro-fit hydraulic rollers.
http://www.lingenfelter.com/mm5/merc...egory_Code=C30

 

unless youre running a huge cam or spinning it way up high they should be fine. Just an option in case.
They just operate on oil pressure so they will open and close like anything else. Id imagine if youre running some overkill spring then maybe a morel is the way to go but GM makes some good stuff. I understand you dont want to use them just tossing the info out there, maybe someone reading the thread may be able to use it.

Guy here has a PDF on it
http://forums.corvetteforum.com/c3-t...yle-350-a.html

.Personally dont care for 1.7 on sbc fwiw.

 

Carb. I just prefer working on them more.
http://www.edelbrock.com/automotive_...r_gap-sb.shtml

This big link below fits the search for a new set of cylinder heads. Any of those brands better for this build?

http://www.summitracing.com/search/D...?Ns=Rank%7cAsc



I'm thinking of taking it to a shop to have a 4 speed manual installed. I had another thread asking about a specific tranny.
https://www.thirdgen.org/forums/tran...22-tranny.html

And it appears that the camshaft you have here won't work, the block is from 78, a generation I block, and the cam works for 87-96 it appears, that's generation II blocks.

 

Here's close to exactly what you're talking about. The LSA is 112 though, I read that a tighter LSA would help with low-end power, or is the 112 good?

http://www.lunatipower.com/Product.aspx?id=1988&gid=289

 

Gen II blocks are the LT ones.

Gen I SBC after 87 was the same as before except that they got roller camshaft with roller lifters. Roller setup also introduced those nice dog bones and the spider in the middle

 

With a carb you'd like to stay around 108-110 lsa for the most part but a cam on a 112 can work.

 

It works fine on older blocks. You and I both specified "retro-fit" hydraulic roller lifters. You would then only need to add a cam-button to your cam gear to control forward thrust.

The heads listed at your link are all for 200cc ports. That's still too big for low end out of a 350 cid engine. A carburetor needs a good signal that a high velocity port produces. The 200cc heads will work, but you may be disappointed in the results as far as low-end power.
A 180cc head is generally perfect for a carbureted 350.

AFR has the best option out there:
http://www.coasthigh.com/0918-p/0918.htm

I suggest small chambers and angle plugs.

Here's a cheaper option in iron. They could use some help on the exhaust side, but over-all not a bad deal.
http://www.racingheadservice.com/Inf...hevy_180cc.asp

 

Generation I SBC were 1955-1986. They did have an engine labeled LT-1. Generation II SBC were 1987-1996 and were based on the Generation I block but had differences. Generation II blocks were LT1. Confusing, thanks GM. The main difference being that the cooling system operated in the opposite direction from the Generation I block. Cooling the cylinder heads first which made the air and fuel mixture colder and allowed for more power. I'm guessing they had different specs here and there and that's why websites allow you to see if cams and heads fit a specific year.

 

From Wikipedia, the free encyclopedia

Jump to: navigation, search
General Motors has produced two different engines called LT1:

• 1970–1972 LT-1 – Chevrolet Generation I Small-Block
• 1992–1997 LT1 – GM Generation II Small-Block

 

gen I still includes 87+ blocks...its just that some 87-99 sbc's used roller cams and had 1 piece rear main seals and the heads used centerbolt valve covers...

internally tho, you could run same crank rods and cam. LT1 I believe is similar internally but the cooling passages and flow direction are different and they dont use a distributor so they are basically a new design, so hence the Gen II.

 

Okay, so I was kinda right but wrong and I've learned something. But the Lingenfelter link does not specify if it will fit gen II or gen I blocks, it just gives years and specific engine labels. And again, it looks like it has a LSA of 112.

 

Sooo.... since I can't find the perfect cam that I am looking for, maybe I can have one special made?

 

These cylinder heads look like a good choice. Is AFR a good brand or should I look for something similar from other companies?

 

AFR is a good brand. THey make good heads with good parts. The package is great for todays aggressive street hydraulic rollers when you order either the 180 or 195's with the 8019 spring upgrade. Even the base spring is good for most cams.

Custom grind is always your best bet but need to figure out exactly what your goals are and finalize the motor specs and heads/intake you will use before ordering a cam.

A gen II cam will fit in a gen I roller motor but you will have to cut down the dowel rod which fits in the timing chain sprocket. Gen II's have a long rod to drive the opti-spark setup and you dont have that with a distributor gen I.

 

Okay, so those AFR heads look good. Go with the Edelbrock Performer intake manifold. And what, a Holley 850?

Is the Air Gap style Edelbrock too high? Will I have a clearance issue with the hood hitting the air filter?

http://www.edelbrock.com/automotive_...r_gap-sb.shtml

 

I completely overlooked the heads you selected. As stated, 180 or 190cc AFR heads are pretty perfect for a virgin 350. The local shop runs AFR heads on his 307 CI bracket car and sinks himself into the low 11's consistently (not at all streetable).

I would stick with a 650 or 670 CFM carb. 850 is way too large.

For a cam, I would be in the .470-.480" range to retain low end torque as well as a descent top end pull until 5,500 RPM. I'm unable to tell you what duration that would be, but most .470"-.480" cams have their powerband end at around 5,500.

Air gap manifolds will not clear under a stock hood. If you flip the air lid on the air cleaner upside down it might clear, I never tried that. The performer manifold is a good choice though... air gap performer is even better if you can get it to fit. (On a rather large like 3-4" tall air cleaner I could not get the air gap to fit under a stock hood. Maybe with a smaller/thinner air cleaner and flipping it upside down to put the arched side down?).

I'd also pay some attention to your rods and pistons with the power you can be getting out of this set up! I'd imagine your crank can handle that kind of power but you should at least pay attention to the rest of the rotating assembly... not to mention you can bump your compression up a bit.



I'm sure some older guys can point you in an even better direction.

 

I like the performer rpm over the performer with heads and cam that big

 

The cam I listed will work in gen1 blocks with retro-fit roller lifters and a cam-button. I have two of these camshafts. They are good for a very wide power-band. I've shifted at 6200 RPM.

An RPM/air-gap style dual-plane would work well. Renegade and Professional Products of (motorville.com) both have versions of this intake for ~$145.

You'll want an MSD distributor - MSD.8361

For good low-end power you want to start out with a carb of around 600 to 650 CFM.

If you like Barry Grant carburetors, then you may want to consider a Race Demon model # 3282010-DR-RS
It's 675 CFM. The suffixes DR and RS are for "drag race" and "removable sleeve". Changing the sleeves from green to red opens the carb up to 775 CFM. This allows you to experiment to find what works best with your combo.

 

yeah, my buddy ran a mild LT1 cammed 350 witih vortec heads and vortec performer RPM intake with a 750 cfm carb and in a 83 shortbed chevy pickup it ran mid 13's at almost 100mph. Thats some good power all around in such a heavy vehicle.

I think a 650 cfm carb could work but dont rule out a 750 if you go with a 224+ deg cam. The milder cams under 224 deg wont really need alot of carb but could work well.

If you buy AFR 180's, and a dual plane rpm type intake, i'd like to see you use their potential which is up 6000 rpm shift by 6200-6400. A 224 cam will do that easily and still have plenty of low end, but very strong midrange and top end which I think is much more fun

 

Haha, I like the feel of stepping on the pedal and being thrown into the seat. I told my dad I wanted to give someone whiplash. But then, too much low end power and you'll be sitting there spinning tires and getting no where. As I've never really driven anything really powerful I wouldn't know what is most enjoyable when driving.

Also, about the intake itself. My fog lights in the ground effects don't work. So I was thinking of running an electric fan on the radiator and running a custom ram air from where the fog lights are, up to the intake. That way I won't need some big 4 inch filter. A stock dual snorkel would work with a stock size performance filter. I don't want AC, so that won't be in the way.

 

So maybe a 224, 0.47 int 0.50 exh, 108 LSA retrofit hydraulic roller. The performer RPM intake, and a 675-700 carb? Good all around power?

 

Yeah something like that should haul the mail. I think you will like it.
Alot of people make a great deal of fuss about low end torque and power...but a higher rpm higher hp setup will run faster and still feel strong because its torque band is moved higher in the rpm band...just have to gear to match to get to the meat of the powerband.

My 383 was not a torque monster by some comparable builds out there, but if you punched it from a mid high rpm first gear roll with 3600 stall, and it hooked, you'd be pinned in your seat. Speed gives sensation of being stuck to your seat. Low rpm torque rush is fun like stock TPI setups but it comes and goes by quickly as the torque band falls off. A good flat torque curve is more fun IMO and thats exactly what a good heads/cam/intake will create.

A bolt on L98 TPI motor could make 330lbft of torque at the wheels. My hsr bolt on L98 made 315 so easily 330+ with TPI. My 383 only dyno'd 372wtq at its peak, but had 150 more hp Only 30-40lb ft more tq but the HP is what you really felt. Huge difference in a low 13 second car and a mid 11 second pull.

Your setup well tuned should be very strong from 2500-6500 rpms. A great street strip fun car.

 

Any specific brand camshaft and carb I should go for?

Are these good pistons?
http://www.summitracing.com/parts/CNN-BC1021-STD-8/

This a good crank?
http://www.summitracing.com/parts/SCA-435020LW/

 

The crank and pistons you're looking at are 900hp peices and very pricey. An OE cast crank will support 500hp, which is more than your streetable carb motor will make. If you really want to go forged, you can find a good forged crank for about 1/2 the cost of that one. For pistons I would recommend hypereutectic for the street. You will get tired of the cold start slap of forged pistons. Keith Black Silvolites are tough enough to handle 800hp, even nitrous or blower apps. And they dont expand with heat like forged so no slap. They're about 1/2 the cost of those pricey gems youre looking at.

I know you say that price isn't an issue but when you get closer to putting all this together, it will become one. You can build a very fast motor , that will take years of abuse without a wimper, for under $5,000. Or you can throw $10,000 away on parts that belong in a NASCAR and not be any faster. The pricey parts wear out just as quick and you'll never use the added strength in a street/strip motor.

When you do build this beast, invest in a good harmonic balancer, and oil pump. Have the rotating assembly balanced at 6,000rpm, so it can live there as much as you want it to. Also, have the block magnafluxed, line honed, decked, bored with torque plates and have the assembly clearanced(blueprinted). All this pays off in durability and knowing that you'll be driving home at the end of race day while others are being towed.

 

Call the cam company to get a recommendation.
If the car is for drag racing in the 1/4 mile, then tell them that.
Tell them your:
engine displacement,
cylinder head type (they should be able to access the flow chart for AFRs),
your intake manifold type,
your static compression ratio,
your exhaust header type and primary tube diameter & length,
your transmission type,
your converter stall-speed,
your rear gear ratio,
your vehicle race-weight.

Good cam companies have simulation programs that can narrow down your optimum power under the curve for your combination. Their recommendation should be very close. They go through this process a lot and will likely have an off-the-shelf cam that will do the job.

 

Interesting. I went with forged pistons because the best I could find online about hypereutectic is that they can take at least 350hp and I'm not sure what my figures will be. The block I bought didn't come with the crank and I just assumed I should go with forged. The engine looks like it had low mileage on it, I'm not sure it'll need to be bored, maybe just honed. It doesn't even have a ridge or any signs of wear. When I got the block I actually looked to see for the cross-thatch pattern. Price really isn't an issue, I'm living with my dad so my only bills are a $60 month phone bill, $50 a month towards the family car insurance, and gas. The price only makes the wait longer. Would piston slap really be an issue if this car is only driven in the summer? Just curious, I'll start looking at hypereutectic. If you want, I can get the bare block out and take pictures.

And a good idea 305sbc but I don't know all the answers to that just yet. I was planning on tearing the car down to the metal and having it painted and everything new put in. The interrior is terrible and I figure the suspension has been running for 26 years, it's gotta be wore out. can't hurt to put in new wires, gauges, weatherstriping, etc... The t-tops leak and such. I'll need some body stabilizing and I'm going to go with a roll cage to make sure I don't twist the chasis. Besides, I wouldn't want to build a beast without a cage, I don't want to die. And I'm changing it to manual so converter stall isn't an issue. Haven't decided on a rear axle and gears. It has only one wheel peel now which won't take the power I'm putting in.

 

Don't trust your eye on the block. that's what machine shops are for. Find a good machinist. Mine here in the NW is Archie Somers. He builds alot of the local NASCAR motors so I know he knows his SBCs. Ask your machinist for advice on this build and to recommendations parts. Chances are he'll offer to provide good parts at a very good price.