I am trying to narrow down my options for my van. I have a 6000lb. hi top conversion van 1996 Chevy Express 1500. It has a damaged vortec 350 now but I want to pump it up. I found a block that is already modified for a 383 from summit: http://www.summitracing.com/parts/SUM-150100/ . I know the cylinders will need to be honed to the pistons but that's it. If I decide to reuse my old 2 bolt main block it will need $800 of machine work. I am planning on using the a scat stroker kit #91100 : 383 9-350-3750-5700-L 2-ICR5700 HYPEREUTECTIC 4.030 DISH 10.4 9.8 9.2 1-91100-1 1-91100 1-91100BIE.
The heads are also cheaper to just buy vs rebuild for use with larger cam. I was looking at the Patriot performance heads: http://www.jegs.com/i/Patriot-Performance/723/2151/10002/-1 . So all I need to make sure of is will I be able to get a cam to match this combo that will be Computer friendly (more for Torque than HP).
When all is said and done I want the engine to be able to tow a boat and a large family with. I will be having PCMforless do my computer to match the engine once it's done. I am also planning on keeping it for a while and I know I will add on goodies to increase it Performance/economy.
So my question is, is it worth it to build my block up for use with the 383 internals or will the block from summit be better? If I choose to build it , will those heads work for what I want? And lastly if everything looks good will I be able to get a cam to match it and still keep it with a good idle. I would like it to have around 330-350hp and lots of torque. Do you think these headers will work too? http://www.summitracing.com/parts/SUM-G9016/. Sorry for the long post. I want something that will last, be strong, and maybe handle extra power down the road.
Another Option:
These have GM 12mth/12,000mi warranty.
GM PART # 17800393 HT383 For EFI.
or GM PART # 12499101 HT383 Carbed engine. http://www.gmpartsdirect.com/
Those engines are super expensive!!! If I build what I want it should run around $2600-2800.
I don't really know the engine I have. I had to buy a used engine because the one I have blew a rod through the side, and they are both 2 bolt main blocks. The summit block is new and has a 4 bolt main. If I wanted to machine my block for a 4 bolt main it would put the cost well over just buying it new already done!
The Summit block would be worth it. You'll have a freshly machine block ready to go. Although, some people like finding blocks and taking them to the machine shop to get them freshened up. The cost would probably be the same unless you live close to a Summit store, I would think.
Your plan sounds like a good one and will probably save you some time and money.
Either way the new block will still need to be honed for the new pistons. My concern is making sure the heads will work with that 383 bottom end and that I can find a cam that brings it all together without losing a decent idle.
What octane gas will you be running? I assume it'll be fuel injected and you'll use the computer? What is the intent of this van?
You probably might want to reconsider the kit selection. You might just have to buy all the pieces separate to get the compression ratio where you need it. Meaning there probably isn't a kit that will offer a piston with enough cc for the heads you plan to run. With 64 cc vortecs and a 12 cc dish piston you'll be at 10.4:1 CR, 18 cc = 9.6:1 and 21 cc = 9.3:1.
I saw somewhere that the stock compression ratio is 9.4:1. I would go with the 21 cc d-cup dish piston and use a cam with a 112 - 114 LSA to keep the smooth idle and to keep the compression ratio close to stock. You could even go with the 18 cc piston to pump the CR, but select a cam that'll work with the higher compression ratio.
I plan on running 91 octane fuel or higher. What benifit would I get from using the 21cc dished piston over the 18cc? Is it just that it will work better with the cam you mentioned? I plan on taking the van on trips and towing a boat or camper behind it, I also like to romp on my cars from time to time! I will be keeping it fuel injected and will be giving pcmforless the build sheet along with a set of dyno runs to assist in tuning it for the best performance while retaining the best posable economy!
This engine doesn't look too bad. I will try to contact them to see what it's output is. Stock compression is 9.4:1... what will dropping the compression to 9.3:1 do to the engines output? Wouldn't I be better off having the compression higher like 9.6:1? Needs some modification to make it work with a computer controlled car. http://www.competitionproducts.com/...ck-Dart-Iron-Eagle-Heads/productinfo/LB383CL/
and have it machined for SPLAYED 4 bolt caps. .that's about the strongest setup you can get. (The outter bolts are tilted outwards at an angle, instead of straight up and down)
i agree!!!!!!
"find a 2- bolt block.. or if you already have one and have it machined for SPLAYED 4 bolt caps. .that's about the strongest setup you can get. (The outter bolts are tilted outwards at an angle, instead of straight up and down)"
My only problem is cost. I want to try to keep it as low as I can. Having the 2 bolt block machined and then fit with a 4 bolt cap will cost well over what it cost to just buy a new 4 bolt block. The new block is only $650 but having the old block machined cost over $800 without modifying it for 4 bolt mains. I love the idea but I am not really building a race engine or revving the crap out of it consistently. Unless If I can buy a block that already has splayed caps installed new?
Even though this isn't going to be a high RMP engine, I would still also tend to agree w/a 4-bolt block- be it OEM or splayed cap conversion of a 2-bolt. At 3 ton-plus weight, that engine is going to be hitting it's torque peak fairly often, and for extended periods, I'd imagine. That is unless you're in the table top- smooth area of the country.
The splayed cap may be a bit of overkill, but I'd opt for it if an OEM 4-bolt block wasn't available.
That said, there are 4-bolt factory roller compatible blocks around that would be cheaper than to splay-cap a 2-bolt block OR to retro-fit a roller into an earlier block.
Even though this isn't going to be a high RMP engine, I would still also tend to agree w/a 4-bolt block- be it OEM or splayed cap conversion of a 2-bolt. At 3 ton-plus weight, that engine is going to be hitting it's torque peak fairly often, and for extended periods, I'd imagine. That is unless you're in the table top- smooth area of the country.
The splayed cap may be a bit of overkill, but I'd opt for it if an OEM 4-bolt block wasn't available.
That said, there are 4-bolt factory roller compatible blocks around that would be cheaper than to splay-cap a 2-bolt block OR to retro-fit a roller into an earlier block.
That's correct, IMO. Or a block like it from a reputable shop near to you to save on the shipping- your total cost delivered to your door in PA is $763.90.
I agree. You might just want to call your local machine shop and see if they have any ready to go. It's not uncommon they'll have a few SBCs bagged and ready to go out the door. Might even get a better deal after shipping costs and all.
No one local has an engine block for the price of the block from summit! So it looks like I will be doing the upgrades I have listed. The only thing I really need help on is what cam to use? I want to keep it a roller style cam! Any recommendations for a 6000lb. van that will be towing a boat or trailer from time to time?
just throwing this out there as my opinion. the motor is going in a van so i assume you wont be turning too many rpms. i work in a machine shop and from past experience the newer model 1 piece rear main blocks are far weaker than the old style two piece blocks. very rarely does a new style block bore at less than .060 over from a factory standard and the webbing in the 4-bolt blocks seems to be a bit weaker than the two bolt. it is easy to use any fuel injection on an old style two piece rear main seal block and if you dont wind the motor over 6500rpm you dont need aftermarket mains of any kind. many people will probably disagree with me but we have 355ci dirt track motors that turn 7000+rpm for 20 laps at a time every week and we never do anything to the mains. personally i would use the old style block. if you are going fuel inj. just block off the manuel fuel pump hole in the block and you are in buisness.
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