Jasonmreiss Posted January 31, 2012 Share Posted January 31, 2012 These are the ideas in my head for my engine build, just curious if someone a bit more experienced would give me a hp guesstimate. '97 vortec block and heads Gm lt4 hot cam (and springs to make it work) Full roller rockers 11 to 1 compression Msd Performer rpm air gap intake 3 angle valve job Holley 750 I have searched and found many comparable but they're all from big magazine companies and may be inflated numbers. See any problems with this combo? Thanks in advance Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted January 31, 2012 Share Posted January 31, 2012 I would guess at 350 -400 hp but with good low end torque.but it is more fun to drive a car with torque than an over-cammed engine that falls on its face when you stab the throttle.I think either Car Craft or Hot rod uses a place called westech in socal.I have spent a day there with a friend while he was getting a boat engine dynoed.they run alot of engines there and the operator knows his stuff.my buddy had a 555" short deck big block chevy built for a jet boat that made 802 hp on 91 chevron pump gas.that wasnt a cheap motor. Quote Link to comment Share on other sites More sharing options...
Jasonmreiss Posted January 31, 2012 Author Share Posted January 31, 2012 That's why I'm not machining down the valve guides for a bigger cam. I've heard these can be torque monsters if built right This will be my first bottom up engine build so it probably won't be right, but I have to do it on the cheap. So no aluminum heads, no extensive machine work. But still ok hopefully. Quote Link to comment Share on other sites More sharing options...
rsicard Posted February 1, 2012 Share Posted February 1, 2012 High Horsepower and Torque from a 383 does not come "on the cheap". Quote Link to comment Share on other sites More sharing options...
Jasonmreiss Posted February 1, 2012 Author Share Posted February 1, 2012 Well cheap is kind of a relative term lol I figure the rotating assembly will be around 900 Cam 300 Intake 300 Carb 300 Dizzy/msd 300 Rockers 300 Varied other items (oil and water pump...etc) 300 Machine work 500 Quote Link to comment Share on other sites More sharing options...
Jasonmreiss Posted February 1, 2012 Author Share Posted February 1, 2012 What I meant by cheap is quality components but not top shelf stuff My goal is 400+ hp, but torque is key. Besides the wife is buying a charger soon and thinks it'll be faster than the z, I just can't let that happen Quote Link to comment Share on other sites More sharing options...
rsicard Posted February 1, 2012 Share Posted February 1, 2012 The key to 400+ HP is the proper machining, proper parts, good flowing cylinder heads and appropriate camshaft. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 1, 2012 Share Posted February 1, 2012 Here's some fairly close comparisons, all the pieces and specs are listed on some - http://www.crateenginedepot.com/store/ZZ383-Crate-Engine-425HP-12498772-P764C510.aspx http://www.crateenginedepot.com/store/HT383-Performance-Crate-Engine-12499101-P7C510.aspx another option with all the extras - http://www.crateenginedepot.com/store/Turn-Key-FastBurn-385-Crate-Engine-350CI385HP-with-Accessory-Drive-Package-And-More-19201331-P944C510.aspx All of the choices - http://www.crateenginedepot.com/store/Chevy-Small-Block-Engines-C510.aspx They've been around for a while but I can't speak to their service. Quote Link to comment Share on other sites More sharing options...
Michael Posted February 1, 2012 Share Posted February 1, 2012 Randy - would it be possible for you to share the price and parts-list for the 555" big-block that you mentioned? There's another thread currently running, where there's a discussion on "price of a 800 hp big block". I'm curious about actual numbers for an actual engine. Quote Link to comment Share on other sites More sharing options...
Jasonmreiss Posted February 1, 2012 Author Share Posted February 1, 2012 Yeah I guess there's some things I won't /can't do that would help As is: Not zero decking Not align honing Not running a monster cam Not buying $2000 heads However I think this is a pretty good package, I guess I'll find out . I don't have a ton of money and I still need just about everything for the car...brakes, coilovers, LSD, interior, paint, bodywork etc... So no 555 for me Quote Link to comment Share on other sites More sharing options...
jt1 Posted February 2, 2012 Share Posted February 2, 2012 Jason, I think your combo, with a decent exhaust, would make 400chp pretty easily. Torque would probably be more, and the hp peak probably in the low 5k rpm range. Looks like the cam is 218/228 @ 50, and with 11:1 and iron (?) heads, it may have some detonation problems, or at least require careful attention to fuel and tuning. Of course, 11:1 advertised doesn't mean you will wind up with a true 11:1, so it may not be a problem. Otherwise it looks like a fun combo to me. jt Quote Link to comment Share on other sites More sharing options...
Pyro Posted February 2, 2012 Share Posted February 2, 2012 You need a bigger cam to run 11:1 cr with pump gas. I run a 292H compcam with 11:1cr with no issues. 292/292 advertised, 244/244 at 0.050". A 383 with vortec heads and a "big"cam can still have good low rpm power due to the small ports in the vortec heads. But I would still recommend a 3000 stall with a cam in the 290 degree range. Quote Link to comment Share on other sites More sharing options...
Jasonmreiss Posted February 2, 2012 Author Share Posted February 2, 2012 Hmmm, well maybe I'll have to dial back the cr, or just do the machine work to the heads do I can run a bigger cam. I just wanted the cheap horsepower bump of higher compression. But I am new to building combos so thanks for the tip, I certainly don't want detonation. Quote Link to comment Share on other sites More sharing options...
rsicard Posted February 2, 2012 Share Posted February 2, 2012 Price out the machine work to the heads first before its done. The valves, valve guides and seats all have to be in somewhat good shape. May be cost effective to purchase procomp 200cc intake cylinder heads from KMJ. Use flat top pistons and get the squish as good as it can be. Smooth out the Vortec head chambers before assembling the engine to reduce detonation. Quote Link to comment Share on other sites More sharing options...
Jasonmreiss Posted February 2, 2012 Author Share Posted February 2, 2012 I have already smoothed the combustion chambers, polished the exhaust chambers, and ground a bit off the spark plug boss. Just some basic stuff I saw in an article about those heads. Nothin fancy as I didn't want to ruin them. Anyway, if I can get 400hp or a bit more, I'll be happy. The entire motor was free so I'd like to use it Quote Link to comment Share on other sites More sharing options...
Jasonmreiss Posted February 3, 2012 Author Share Posted February 3, 2012 I just read a write up that made 401 hp, it had 9:1 compression, stock vortec heads, a hollley 750, the hot cam, hei, and the air gap manifold. It was a 350. So I'll go ahead and keep my hopes up. I'll have more displacement, and a better ignition system, plus the little head work done. From the sounds of it I'll probably stick with 10:1 or so compression. All the torque is made early so it should a fun street car Quote Link to comment Share on other sites More sharing options...
logan1 Posted February 6, 2012 Share Posted February 6, 2012 (edited) the Vortec heads come from the factory with a 5 angle valve job; just leave them alone and you'll be better off. Instead of spending the money on a 3 angle valve job get the heads ported. Edited February 6, 2012 by logan1 Quote Link to comment Share on other sites More sharing options...
Jasonmreiss Posted February 6, 2012 Author Share Posted February 6, 2012 Well I was bored and owned a dremel, I did a couple things on my coffee table to 'port' the heads. Honestly I probably did more harm than good, so in my boredom I may have nicked the valve seats. I don't really know but figured I'd err on the side of caution and get a valve job done. I wish Id of had more experience and known better, but it is what it is. Should I get the valve job done now or just cross my fingers? Quote Link to comment Share on other sites More sharing options...
jt1 Posted February 6, 2012 Share Posted February 6, 2012 You can mark the seats with a magic marker, put the valves in and spin them (with a drill or with a stick and rubber hose) and see if the nicks are actually on the contact area of the valve and seat. If not, they're probably OK. If you know someone with some engine building experience, you could get them to take a quick look. jt Quote Link to comment Share on other sites More sharing options...
billyssp Posted February 27, 2012 Share Posted February 27, 2012 You need a bigger cam to run 11:1 cr with pump gas. I run a 292H compcam with 11:1cr with no issues. 292/292 advertised, 244/244 at 0.050". A 383 with vortec heads and a "big"cam can still have good low rpm power due to the small ports in the vortec heads. But I would still recommend a 3000 stall with a cam in the 290 degree range. i would like more info on your combination. Quote Link to comment Share on other sites More sharing options...
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