I need to rebuild the bottom end of my tbi Vortec 350. I'm looking to get 360-400 horsepower out of it. It NEEDS to run on pump gas since it's my daily driver. I'm looking at eagle rotating assemblies and they look like the best deal right now. Any other suggestions? Btw try to keep it affordable, I'm still in high school. And I don't plan on boring the block out.

 

If you need a rotator go with a 3.750 I am not a big fan of Eagle components as I have had my share of that stuff over the years.

I consider Scat a better choice over Eagle.

I use all Callies rotators and so far no problems, Quality parts but do cost more but you get what you pay for.

Leak down numbers after your build is done will tell you if you need to bore it or not.

 

How much more is a scat rotating assembly?

 

If you go with a 3.750 stroke Scat crank they run about 150.00 to 175.00 and don't cheap out on the rods and go with the Scat I beam with 7/16 bolt as you won't need a small base circle cam those are about 300.00 to 325.00 Pistons I use the Mahle or you can get the Wiseco Protrue pistons for 380.00 a set. balancing runs about 200.00 to 250.00

DON' BUY A PREBALANCED SET UP!!!!

 

I can balance them.... What's wrong with a pre balanced set?

 

Been through a lot of Prebalanced rotators they don't seem to be that close and everyone I have seen the piston box is still sealed along with the rods are still in there sealed plastic bags. How do they come up with the correct weights ???

One rotator one end was off 32 grams.

If you got a crank balancer you should b all set !!!

 

For the price of these parts this motor better be strong... And yes I know. This hobby isn't cheap.

 

I very rarely use cast cranks!!

Go with a 6 inch rods as you can internally balance.

 

Will ported vortec heads, lt4 hotcam, air gap intake, and that bottom end setup make 400hp?

 

Should be over 400 horse!!

 

400 is about the ceiling for Vortec heads.... by the time a 383 with a decent cam is in 400hp territory the vortecs are calling it quits. But with a decent mid level roller cam (something like an XR276 or XR282) and a 383 you should be right around 400. You'll make as much as the heads will allow. Just remember not boring may cost you power long term if the ring seal isnt good enough.

 

383's I have built with Vortec heads have been in the 460 horse area and 485 on torque.

NOT WITH THE MEXICAN CASTINGS!!!

 

Thats as cheap as it gets for rotating prices... But they are good parts and will work for you

 

Are we talking engine dyno horsepower or fwhp horsepower in the car through a full exhaust system? I've never seen anyone with a weight/trap speed combo that indicated over 400hp at the flywheel on Vortecs without special headwork done... but I've seen a lot of 350s get very close to 400. Just my experience. I think a 383 might get there.

I dont really know anything about 'mexican castings'. I've never heard of them or heard anyone else mention them. Are they replacement crate motor vortec heads or something?

 

Just reuse your old stuff. You don't need new parts to make that much power. Take the money you would spend on the kit and have the motor machined. Re use your crank and rods and if you can the pistons. Buying a new rotating kit will not make your car faster unless your raising compression or stroking the motor.

 

The Mexican casting are the only ones made these days unless you are talking about the bow tie castings.

To the original poster, You certainly can reach your goals with the stock crank easily with the right selection of parts.

 

I made 405 hp and 405 tq on a 350 with 107k on it on my vette. Fuel injected also.

 

The Mexican casting have a small runner like 159 CC compared to the 906 and 062 non Mexican heads which have a 170 intake runners.

 

Using the 906 casting and on an engine dyno I have seen 460 horse 383 engine.

I have had some street rod engines .450 lift cam zero decked, plate honed ETC. with stock Vortec heads are right at 375 horse these were kind of budget builds.

Here is a 355 with Dart Pro1 heads made 459 horse and 455 torque on my F/B time line.

https://www.facebook.com/photo.php?f...type=1&theater

 

When I go back and read your original post, this is the best reply you've received:
.........especially given this: "And I don't plan on boring the block out."

Take it to a good machine shop and let them check it out. If the cylinders are straight and round, just a hone and stock pistons can help keep your build "budget" and not give up anything powerwise. Pick your headgasket and deck accordingly to shoot for 10.0:1 CR with that Hotcam.

 

Had those "Hecho en Mexico" 062 heads on the 2nd 350 Vortec in my 1997 Express. I always wondered why the GM Goodwrench crate engine with 062s did not perform as well as the original Canadian 906 head engine. The 062 crate engine heads were only ~200ish CFM @ .450" lift. I replaced those junk heads with a pair of Etec 170s.

 

I can't reuse my old bottom end. My block is now junk and need I find a used vortec block. I was going to buy a used block and just rebuild the bottom end and use my heads, cam, intake, and basically new lifters again. I'm curious on what's the best to buy for the bottom end.

 

What do you think of this block?http://minneapolis.craigslist.org/an...749869243.html

 

Looks like he pulled it put of a swamp


What is so bad with yours again?

 

It was a roller block out of 93 roadmaster. According to my dad, one the main bearings is out. He says when a main goes out, a block is usually junk.

 

No sir.

 

It at least has to be machined out. I don't think it's worth to machine this block. Why wouldn't I just find a different one?

 

Lemme ask you this do you know what what needs to be done to the block you posted>

So...you're original block spun a bearing...has happened to millions of blocks...that is why we have machine shops.

 

Spun main bearing may just need a line hone at machine shop, and crank turned at machine shop to fix.

Spun rod bearing (like on engine you linked too) will need crank turned or replaced, and rods resized or replaced..

Take what you have now to a machine shop and talk it over with them 1st.

You may have your block and crank ready to go for $300 or less.

 

I see alot of blocks with spun mains and 98% they can be fixed by fitting another cap on and align hone should fix it.

 

Would be an excellent time to upgrade a 2-bolt to splayed 4-bolt caps as well.

 

Ya more so of going to stroker build but its best to sonic test before putting on splayed main caps.

 

I am building a new vortec block now and would advise not using a vortec block. There are a few differences in the block that I don't like. I would try to get a good L98 long block or a 1 piece rear seal short block that has all the factory roller cam and parts with it and put vortec heads on it.

 

What do you consider a Vortec block??

 

I have built a few roller cam engines and never found anything I did not like better with the vortec blocks. Sonic testing shows the bore thickness is more consistant and in general the castings are much cleaner. They do not require as much clean up work. Not as much casting sand left behind, etc. I have also noticed that many of them go 200-300K with very little to NO measureable taper or out of roundness. I have a 220K mile L31 I pulled from a 1999 Suburban that I literally honed the block and put a set of stock bore flat top pistons and file fit rings in. The crank had a few worn journals that were pushing the service limits and had to be turned .010/.010 but otherwise it was all in great shape.

If someone says something about the missing bypass hole, I am going to smack them one as it is stupid easy to work around. I block that passageway off on the older engines I work with anyway.

 

What's the difference? Sorry for asking many questions.

 

In stock form there are a few things I would fix. #1 I don't like that the timing cover is missing 2 bolts and would have a machine shop drill them so you don't have to worry about a normal timing cover leaking. #2 the bypass port for the water pump on the passenger side of the block is not drilled. The vortec heads them self have larger than normal valve stem seals and the boss below the seal is larger than normal and you have to either machine the boss down to run normal springs and normal seal or run beehive springs.

To get around these problems with out machine work I am running an Edelbrock 8810 short pump that has a bypass port and clears my timing cover but now have to run accessories for a short water pump. I also am running the comp beehive springs to avoid machining the heads. When you do a cam swap there is no timing cover gasket. You have to replace the whole cover. Also the factory and GM replacement cams like the ZZ4 and LT4 hot cam require special gears on the distributor designed for steel cams and will damage a normal iron gear also the block will not except a manual pump because the hole for the fuel pump push rod is not drilled, the pad for the mound is there and drilled but there is no hole in the block.

The things I like are that I believe the casting is Chevys best casting, 4 bolt main, Great connecting rods, Hypereutectic pistons with 9.4 compression and probably the best flowing factory heads you can get for the sbc. My motor is new so I am not going to have it machined and if I was rebuilding it these would be easy things to fix but I am not so there annoying problems to me.

 

Ok fast slap away. O ya the stock timing cover has less room behind it and will not clear a double roller timing chain from what I hear so I was stuck running a single roller

 

If I was running a restrictor plate instead of a thermostat the water bypass not being there would not bug me but I don't want my pump dead heading when my T stat closes.

 

Most of these are issues on any build. Vortec heads are the best factory heads GM made. The valve lift limitation is easily fixed at the machine shop, ghetto grinding the retainers, or some beehive springs (such as the GM LS2/LS3/LS6 springs with more mild roller cams like the LT4 hotcam). The distributor gear issue is gonna be a problem with pretty much any roller cam build. Electric pumps are far superior to mechanical pumps. I'd much rather run an electric pump, and most of these cars already come with them. All it takes is a Mallory 4309 and a factory pump and you've solved that problem. My late 80s 1pc truck block doesnt have the fuel pump pushrod passage either. That may be something that ALL 1 pc blocks got rid of.

The timing cover thing is weird, though. The cover itself is its own gasket?

In general, Im all about an L98 longblock, with 083 or Vortec heads if you have to go factory irons. 083's are very underrated, TPI is what holds them back. They're not spectacular, but they're more than adequate for a moderate budget build.

 

Ya the timing cover has molded rubber cast too it and is part of the cover. My new comp cam can use a regular distributor gear as most aftermarket cams can. I just had to add that to my list of rants. I think your rite I think all 1 piece rears must not have fuel pump push rod holes. The block can easily be modified if your machining the block. I have a spare summit block which has all the work done to it and is like a normal older block except that it uses a 1 piece rear seal and can use factory roller lifters. My problem is my block is new still in the plastic and I don't want to have it disassembled and put back together. I'm not a fan of electric pumps.

If you get a vortec block spend the few extra $ and have the timing cover bolt holes added, water bypass drilled and fuel pump push rod hole machined, heads machined for screw in studs and valve guide boss and valve spring pockets machined. Re use the rods and crank and get some good .030 over pistons that will give you the compression you want. The boss below the valve stem seal is larger than normal and if you want to run a normal valve spring you will have to machine it other wise you cant use the damper spring in them which you don't want to run with out on normal springs.

Are you planning on reusing your TBI?

I agree HINKSON I had an eagle 383 kit that was pre balanced and was shocked when non of my pistons or rods were numbered and non of the parts were balanced, just the crank. My rods were sealed in plastic. I never used the parts and never weighed the parts but was very skeptical. It did come with a sheet that had what the weight of what every thing was suppose to be.

I would just get a cam kit, have the whole motor rebuilt with the stock heads and swap the TBI to carb. You can make 350 HP at the motor with stock heads its about the limit of them but its should not be a problem.

 

My current motor build I am doing I wanted every thing new but my next build I am doing a SB 400. If your going to go through all the trouble of tracking down a used motor maybe trying to get a good 400 to build would be for you too. A 400 with stock crank, some 350 5.7" rods and vortec heads would make awesome power for the street. You have to have 4 steam holed trilled in each head which is way simple and would be cheep if you want to use them on a 400, it would give you good HP per $. If your trying to get your money worth and going to buy a used block you might as well start with the largest motor you can. You will get BB torque in a SB package.

 

Yeah I think 400's are discouraged for drag racing... I know 1gary constantly complained about how the blocks would shift and give you different compression/leakdown numbers after every session. But for a street car or something that doesnt need ultimate consistency all the time it'd be a fun option. You just get stuck with a 2 pc RMS (if you go T56.... $$$$$$ flywheels) and you dont get to use cheap roller cam hardware. Those are both pretty big drawbacks. Between the two of those, if you have a 383(with a 400 block, 3.48 stroke) with a T56 and a roller cam, you have to pay an extra $1000 at least compared to a 1 pc rear main 383(350 block, 3.75" stroke). Ive often pondered a Dart SHP 400 1 pc block with a 350 crank in it for autocross. Im not big on "destroking for revs!" but for something that I would intend to spend a lot of time in the mid-high ranges constantly, the decreased piston speed should help with durability.

 

Ya I would not use a 400 for high RPM unless it was de stroked and forged. The pistons are heavy and the blocks are weak but they make great street motors. I almost got a dart SHP 400 with 350 mains and a 1 piece rear seal instead of my vortec. I still want one. If your looking for a low RPM stop light to stop light sleeper though there great. slap some 350 rods in it, replace the pistons and keep the RPMs to 5,500 or under. I am planning on building one after my vortec for my 4X4 with 461 heads, 350HP 327 reproduction cam, cast iron marine intake, ram horns, duel points and a Q jet.

 

Whats considered high rpm? Factory internal 400 i agree is a stump puller. I dont like the short rods. But if you build one with 6" rods and pistons, you can turn rpm fine. I turn my 400 shp build to 7200

 

Ya 7,200 is high RPM. You would scatter a stock 400 bottom end.

 

My fathers last 454 had a 7,200 RPM red line in his Camaro.

 

Before I had the main bearing go out, I got everything to work perfectly.. Surprisingly, the TBI seemed to keep up with the motor. And it got good mileage. I was getting 17-20mpg in the city. I don't want give up the TBI...

 

Just buy a complete balanced rotating assembly from Crower and be done and have the best. They have different versions depending on how lightweight and strong you need it to be.

 

Maybe just getting a new or rebuilt motor might be a good idea. My vortec 350 was $1995 shipped to my door. Getting a used block, having it machined and buying a rotating assembly is about the same price.