I'm currently looking around for maybe doing a twin turbo 305 build. Reason TBI 305 engine out of my camaro last august. My dad still wants to keep the engine, so its sitting on a pallet with plastic covers over it under our bench at our shop. Far as I know it had a heating problem, Im thinking it might be just a blown head gasket problem. (the antifreeze was disappearing alot.)

I plan on taking a overhauling engine class for my senior year next year, and they require me to bring in my own engine. I figure i'd bring in my 305 to work on, but I didn't want it to be just a ragular engine. I wanted to do something different with it.

My friend that is about to graduate from wyotech has been giving me some advise and ideas what to do.

First we thought about the "305 stroker kit" 335 kit, I wanted to have forged pistons and a strong crankshaft to handle power adders too.

so he talked me into going to have low compression, and have a supercharger and low end torque.

I look into most superchargers and their pretty expensive for some I want.

I thought about maybe do a twin turbo kit with it.


I do plan on putting in a forged crankshaft rebuild kit from PAW into it, might change the piston sizes to something bigger. (maybe, depends)

I do plan on putting in a .500" lift 350 hydraulic roller camshaft maybe more, I would have to look into the cams more.

and I thought maybe put on 305 votech cylinder heads (Maybe 305? my friend said I'd might lose power if I put on 350 cylinder heads on) and get a port job for the cylinder heads and the intake, and I'm not sure what type of carb I want to use, but use a mechanical secondary holley carb.

I don't know where to look for a twin turbo kit, I'm thinking I might just go for ebay tt kit :-\ I know its not a known brand kinds, but do ebay TT kits really do work?

T3/T4 oil cooled turbos.

if anyone else have a segguestion for a twin turbo kit, would be great, but I really dont want to put too much into getting a TT kit, fact I might already put alot into the engine it self.

And my final question so far, Would this be a workable project to do and try?

Please message back, I would really like find out what I could possibly do, or maybe I should do something else to the 305?

I really don't want to see an engine go to waste. and my dad still beleives its a good strong engine, which it was, it put up alot of good abuse.

Thank you,

Tim

 

If you are thinking about turbo go with EFI. By the time you buy a blow through carb you could have Megasquirted a TPI manifold.

Vortech heads are a good choice. most of them are smaller combustion chambered heads so get those before you choose your piston.

It will be interesting to see a 335 turbo engine! It kind of make me excited for you to get it done!

also make sure that the deck on your block isn't warped before you take it to the machine shop. If it is pushing coolant it could be the heads or block is warped, or it is a head gasket. Also if you get a new crank you are going to have to line hone the mains.

I think it is a good idea! I am excited to see what might come of it!

 

Where to start. Twin turbo generally ends up costing far more than supercharging, and makes tuning a little more complicated. But that's not a deal-breaker. Next, Vortec 350 truck heads are advertised as 64cc, but generally measure closet to 61cc. Resurface those and you're at 60cc. The 334 stroker: If you want an off the shelf piston, without using 5.565" rods, the only one I'm aware of is from KB. It has a 10cc dish. So, you use these and build a 334, and top it with 60cc heads. That puts you at 9.7:1, more than ideal for boost. And if you're turbocharging, you really don't need an extra 24 cubic inches. Also, let's assume Edelbrock Etec 170cc heads, for your small bores. Now, new heads are machined while still hot from casting, then they're put in the box for shipping and sale, and in the box they cool, so when you take your new heads out of their boxes, they may need resurfacing to be flat. We'll assume 62cc, and Keith Black dished 305 pistons, again bored 0/030" over. This combo would put you at 8.82:1, which is just fine for boost. Still, these pistons are hypereutectic, not forged. And with boost, you want forged. That means custom pistons. So now you can do a 334 with a custom 17cc dish and be at 9.0:1 with the Vortecs at 60cc

 

I would have to say that supercharging is only cheaper when you don't make your own hot parts for the turbo. If you buy a kit, it will kill your budget.

 

I see.
I did noticed I couldnt get a forged 334 stroker kit. kinda makes me wonder about it.
I was also consern about maybe I wouldnt have to get a 334 stroker kit, because I like the idea of turbocharging the engine. I've been looking into the TT kits for a while. I was more planning on using TT for a 383, or a 350 instead, but since I already have an 305, I thought it would be pretty neat if I made that into twin turbocharged.

Maybe I'll go get the 334 stroker kit, and change the pistons like you said, but would I need to get a different crankshaft?

I have an understanding what your telling me, and it sounds good to me. Im sure that this will become very exspendsive project. but I hope to see what I will able to get over the summer when Im working all the time.
I'm hoping maybe I'll have the bottom end parts (pistons, crankshaft, etc.) maybe the cam, defantly the cylinder heads, and hopefully the vavletrain parts.

 

there was a guy in hot rod magazine a while back that twin turbo'd a 305, it was called taking the turd out of third gen, or slomaro build or something.
I think he improved his oil gallys and oiling system when he did it too... I wish i could find that arcticle for you, I have a stack of a couple hundred mags to go through....

 

There's no good reason to not stroke it, as going the TT route means you should upgrade to a forged steel crankshaft anyway. Your 305 rods aren't up to high-rpm use, so get some I-beam rods that use capscrews rather than old through-bolts with nuts. Plan on having to order a custom set of forged dished pistons with plasma-moly rings. Plan on then having your block bored and honed to 3.766" You need to choose heads before ordering the pistons. Figure around $650 for pistons with rings, $200 for rods, $600 for a 4340 crank, $200 for balancing, and $300-700 for block machining.

 

not interested in the tt but i got a 305 i was thinking about strokin for my tpi could u point in a direction for crank and piston set up im getting my stok heads work with the 3 angle and bigger valves and stiffer springs but want a combo thatll hold up across the board any 1 interested in the help can simply shot me a pm itd be GREATLY appreciated ps 2 kids definately on budget not like most i look for second hand alot of the time but the stroke will be all new parts
thanx

 

Why mechanical? I'm going on my third VS blow-thru conversion, no problems whatsoever. You just need to know how to set the carb up for blow-thru, as well as set the secondaries up with the right spring and corresponding solenoid. Total cost, including the carb, and accessories, under fifty dollars. I just started another conversion for my cousin Rob, and if you'd like, I'll document the conversion here in the power adder forum to help you out....

This is what he's started with....;



.... and this is what it looks like right now. I'll have it done for him in a day or two;

 

u prolly better off with just a stock rebuild. and a single mpt70
hot parts fabricated from exhaust tubing and stock manifolds.
with blowthru and msd 6al ignition.
MSII will be complicated, for beginner. esp. with turbocharged engine.
on turbomustangs.com u will find all the info u need to convert your holley double pumper for basic beginner blow thru. u can do at home with simple hand tools. i reccomed a single plane like a weiand excelerator. with stock type cam, or cam with more exhaust duration.

 

that would be wiser, but remember how it is when you've got your heart set on something.

 

I've been doing some looking around, Would these cylinder head would work? EQ lighting vortech 305 cylinder heads sound pretty good, what lift should I go for? more than .600" lift or less? the price isnt bad. any suggestions?

http://www.shaverengines.com/EQLIGHTNING.html

I was reading over the article of 150 HP for a 305 Chevy Engine - Hate Me, I figure alot of what they used would be a pretty good idea for the top end parts, I think I may go with what they went for a cam, but I'm not too sure about cams... :-(

http://www.popularhotrodding.com/eng...e_testing.html

I might go with an intake like that. maybe not. I'm not worried about clearance, and I don't plan on putting this engine in my car. I want to build it, to what I want and once I decide to pull out my 350, I'd put this engine in, or maybe even in a different car.

I found this 335 stroker kit on powerhouse, I looked around on this message board and most people said to go there. The do have Hypereutectic pistons and a cast stoker crankshaft. I wonder if it would be possible I can call them and ask them if I could get them forged instead? and along with getting plasma moly rings?

https://shop.enginekits.com/osb/itemdetails.cfm?ID=341

 

Everyone correct me if I am wrong, but isn't a 335 made out of a 305 with a 350 crank?

If that is true you should look into buying parts separately (crank, rods, pistons)

the biggest thing is to consider how much power you want to make. If you are going to only run 6psi and don't want to upgrade it anymore you can run the hypereutectic parts. If you want something that will never come apart you need to buy forged parts separately.

The nice thing about a crank though is that it is rotating mass. It isn't putting as much pressure on the crank like it is the rods or pistons. You might be able to cheat in a cast crank depending on how much power you want to run.

 

I would like to see that conversion documented!

 

We'll have some video for you too at the track, just need to fine tune w/the jets when everything is up and running....

 

hm... I've been asking a friend about this build, he thinks I'd be wasting my time using a 305. I do understand 305's arent the best, but he kinda finds them useless engines. maybe I would use the same money to put into another 350, but I don't want to do that. I want to make due to the 305.

I'd have to look into the crankshaft, I think it is a 350 crankshaft, I'd might just buy separate parts, make it a little more cheaper than buying kits and get parts I don't need.

I do want to have over 6 psi. I want something that could be quicker and meaner and have more performance than my 350 has (which has 360 hp, and 380 tq) I do see that engine being quick, but its like... Not quick enough, I'm rather disappointed in that engine.

I also plan on rebuilding my 6 speed tranny, because 5th gear has gone out, and it grinds in 6th, reverse, and second gear a few times.

I also hope to get a lightweight flywheel with a clutch that RAM made.

get sub frame connectors, strong torque arm, stronger sway bar. maybe a few other things I need to make the body strong and realiable.

I plan on also putting in a posi with 4.10 ring and pinion gears in the rear axle. I'd probably leave my axles alone until I break one or think I do need to change them.

I would redue my exhaust for the turbo exhaust, but I probably wont have the exhaust run all the way back since I know people have clearance issues, more likely I'll run them off the passanger side, or may figure something out. but I dont imaging putting alot into exhaust, other than have 3 inch exhaust.

 

im actualy prety interested in doing the same thing.... i found a 305 chevy buildup out of the March 1999 issue of car craft mag. they sucesfuly built a 305 to 325 hp and 317 TQ with bolt on mods

i figure if i work a little on it i can get thoughs nubmers up with a twin turbo setup...

The websight is what got me to buy the Mag if you really want or anyone email me or msg me and ill scan in the pages of the buildup 4 u
www.goingfaster.com/spo/325_horsepower_305_cid_chevrolet.html


Things i need to look into yet... (im assuming you also)

what is a good radator to handle the extra heat created???
Are brand names a big thing when it comes to turbos?
I would like to keep mine TBI if possable.... how can i acheve this?
Best ways to keep this Affordable??

I know alot of people will proably knock this kit right off the bat but what do you think? woudl something like this be worth getting and maybe upgrading the turbos in the future? maybe after the die?

http://cgi.ebay.com/ebaymotors/ws/eB...3AIT&viewitem=

 

that kit has alot of stuff u would never use. those turbo headers wont even work on an fbody they stick the turbos up way to high.

a pair of cast iron manifolds out of a 2ngen f-body can be modified to work though. im working on a set ort well will be modifying a set for a friend on the boards

http://cgi.ebay.com/ebaymotors/TWIN-...QQcmdZViewItem
u need something mor elike this

 

a 305 with a 350 crank gets you a 305 with a crank that's overbalanced. Both the 305 and the 350 use a 3.48" stroke.

 

i dont understand y build a 305 or 335 stroker, when a 350-383 will cost just around the same for the rot. ***.. its not that hard to locate a 350.

if it was me and i had to build a 305, it would just be a stock rebuild with better head gaskets,bearings,bolts and 10psi with premium gas and meth.
i think the stroker 335 guys are gonna be dissapointed with the results.
the bore of a 305 will hinder any real good flowing heads. but with a turbo it doesnt really matter.

 

Are you sure they wont work the kit specifies for a F body camaro/trans am

if your sure they wont work what kind of headers do work any brands.....

any tutorial laying around on how to modify the ones your working on maybe a pic

 

I noticed that you seem to be set on a 305, but I will give a little bit of unwanted advice anyhow.


The difference between a 305 and 350 is the bore size, the 350 has a 4.00 and a 305 has a 3.7??, you can not bore a 305 to a 350!, they also have the same stroke of 3.48, the 335 uses a 400 crank with the main journals ground, or more likely an aftermarket crank with the 400 stroke.A 383 uses the same crank, but due to the bore size gives you an additional 50 cubes.

There is absolutely no good reason to build a 335 unless you are restricted by a racing class, even if you do save money on a core, this cost will be more than offset with the cost of pistons, the 383 pistons will be considerably cheaper, and the additional cubes are irreplacable.

You seem to be new high performance, and I am happy to see new people in the hobby, but my advice to you would be to slow down a little bit. It takes lots of practice to get even a simple high performance NA combo to run well, to expect to get a twin turbo combo to work would be akin to pulling teeth, and you will probably destroy more than a couple motors in the process.

If you can just find a 350 core, do a stock rebuild in your class, throw on some AFRs and a hy. roller cam, you will be so impressed with the performance, and tuning the combo in to run really well will be a great learning experience.

 

Whipple made a supercharger specifically for a TBI setup. I don't think they make them anymore but there is usually a couple of them floating around on ebay at any one time. It should bring a bone stock 350 TBI from about 220hp to around 350hp. I'm not sure how much it would improve a 305. Might be a cheaper route to go depending on how much cash you have to burn.

 

hm...
Well I did a rough estimate of how much this will cost just with in the engine and the turbos.
I'm not sure how twin turbos project becomes expensive over if I was going to put on a supercharger. maybe I'm figuring it out wrong.

I'm thinking I will go for getting a 350 engine block some where and get it machined and get the parts I believe I should get for it. but I'm kind of concern about price after thinking about it. it could be possible, but I really don't want it to be more than $6,000 (I'm taking it would) I only have a year after this before I graduate, and I yet don't know what school I want to go into after I graduate. I was maybe considering taking a year off before I go off. but most my friends and everyone is telling me not to, because I will never go if I don't go after my senior summer break. I can understand that. so I'm kind of a bind right now. I know I can pull it off, it just depends how long it will take me to work it off.

:-\

I know horsepower doesn't come cheap, but it would be nice to find a good path to go, something with a power adder, and be worth my money, and something for me to be satisfied with.

 

I've been in your shoes when I was in high school years back. I had to put projects in the back burner for a while to focus on my career and school and in the long run that paid off more because just waiting a few years gave me the money and time, as well as a garage to start a project car in my own time. The things I wanted to do with a car changed drastically in those few years as I learned more and more about fabrication and all around mechanics. Projects like the one you are describing, while doable, are very expensive and time consuming. It's not a bad idea to sit back and explore other possible routes and decide what you really want out of your car and what you can realistically accomplish. I also have 2 cars, one for fun, and the other for work and commuting. It makes things alot easier. My opinion on the build would be to think on it and explore other possible alternatives. Not to mention decide what's going to be your main proirity after high school.

 

Just to clear some of this up... no, a 335 is not a 305 with a 350 crank. For most of the 80's the 305 and 350 used the same PN crank (though they did have different counterweights), which is to say, they had the same stroke. A stroker 305 is done like a stroker 350... stick a 3.75" stroke crank (originally a 400, now there are cheaper aftermarket cranks with the right counterweights than the originals that you'd have to spend a lot of time balancing) in it.

Why? Well the aftermarket parts cost the same as those to do a 383 and tons of us have 305 cores (or can get them for free), where 350 cores still fetch a few $. Beyond the few hundred $ savings, the smaller 305 bore has advantages in both detonation control and combustion efficiency, making it interesting for experimenting along those lines.

 

in what ways dose it have advantages in these areas can you explain?

 

Typically, a smaller chamber and bore, assuming the same basic design will have a shorter distance from the plug to any point in the chamber, the flame front doesn't have as far to travel, and flame front propagation happens faster in a more confined space. The faster you get the a/f charge burnt the more force it exerts on the top of the piston and the less chance that spontaneous ignition from other sources can happen before the flame front sweeps the chamber, preventing detonation. You also get advantages with less chamber surface area (with respect to this discussion, primarily less heat transfer both ways).

 

I was in the exact same boat a year ago, I had my L69 305 that was leaking every fluid it had and I was dead set on rebuilding it with a hotter cam and the EQ 305 heads. What I wound up doing was finding a u-pull-it junk yard. These types of places are all over the country and 350 blocks are plentiful in them, and their parts tend to be really cheap. In fact it took me a whole day of examining various motors until I settled on the one I wound up buying, which only cost me $59 for a complete bottom end (would have been $129 if it kept it complete). It was a bit of work getting it out but the savings was worth it, and If you don't have the time I see'em all day long on craig's list for about $100.

p.s. I'd still use that 305 for that engine rebuilding class you mentioned, this way your hot 350 going into your car isn;t the first engine you've ever put together.