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10-12-2012, 04:10 AM
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350 TBI first time rebuilding engine...question
Hi
 How you doing guys? I decide to rebuild my 350 TBI engine for 1993 In real... I jut need your help friends  I took a stuck engine and want to turn it to performance engine I over size the engine 4.030 I boght my comp cam kit COMP Cams K12-365-4 - COMP Cams Xtreme Fuel Injection Cam and Lifter Kits - Overview - SummitRacing.com Rockers 1.6 ratio and pushrods Magnum Pushrods: 5/16" Diameter, 7.800" Length COMP Cams 1416-16 - COMP Cams Magnum Steel Roller Tip Rocker Arms - Overview - SummitRacing.com COMP Cams 7372-16 - COMP Cams Magnum Pushrods - Overview - SummitRacing.com Vlave from summit racing : Intake :Summit Racing SUM-V8000-8 - Summit Racing® Race Valves for Chevrolet - Overview - SummitRacing.com Exhust:Summit Racing SUM-V8008-8 - Summit Racing® Race Valves for Chevrolet - Overview - SummitRacing.com Piston and ringes: KB piston Keith Black/KB Pistons 9903HC-030 - Keith Black KB Performance Claimer Pistons - Overview - SummitRacing.com summit rings: Summit Racing SUM-133-M139-30 - Summit Racing® Piston Rings - Overview - SummitRacing.com summit racing Connecting rods: Summit Racing SME-3-48-05B100 - Summit Racing® Stage I Connecting Rods - Overview - SummitRacing.com I get summit racing rods and it's written on it"scat" I want to know is it a china product or not??cos in google search all write it's china. And the piston dome -14 cc....should I keep the recommend GM timing or need to dgree the cam? Also does any thing wrong with my parts....all are fine and fit the engine? and approxmately how many the hp for this engine? the KB recommend the gap for the piston ring 0.026 for the steet normal aspirator and 0.032 for the street tow. I use the car for loading stuff so will make the gap 0.030....is it ok??and should I make the first and second gap the same or only the first ring? the gap now is 0.013 and I thin it's too tight ..what you recommend guys....filing the both rings to 0.030 or just the first? 
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10-12-2012, 05:23 AM
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1.6 rockers on the street??. Are you sure about that or is that a decision based of magazine article build??. Often those are used as a band-aid(a poor band-aid) repair to the wrong cam choice. Since you haven't bought the cam yet.....................
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10-12-2012, 05:58 AM
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350 TBI first time rebuilding engine... question
Let's start out asking if this is going to be a daily driver? Have you had the block, crank, and heads to the machine shop yet? Are you using the heads that is on your motor? Using your 1993 GM heads will need some work, mild porting to get them to breathe better. The pistons you list with the 76cc heads will have a compression ratio of 11.3:1. Too much to run off pump gas. You need this set of pistons if using your 76 cc GM heads. Keith Black/KB Pistons KB106KTD-030 - Keith Black KB Performance Piston and Ring Kits - Overview - SummitRacing.com or these http://www.summitracing.com/parts/UEM-9902HCKTM030/ Use a Fel-Pro 1094 .015 steel shim head gaskets (4.100 x .015) if your block has not been decked. This will give you a quench of .040 which is good for using pump gas. Your compression ratio will be around 9.1:1. The Scat rods are from China but are good rods. The top ring gap for the top and second ring should be .026. Unless you are doing a lot of heavy towing I would file them to .026. If you do decide to open the gap just do the top ring gap. I would also call Comp Cams to see what they suggest for your camshaft. I don't like the exhaust lift lower than the intake lift. Most stock heads need higher exhaust lift. I would suggest the Comp Cams K12-262-4, 218/224 duration, and 0.464/0.470 lift. I would call Comp Cams to get their opinion.
Last edited by cdminter59; 10-12-2012 at 06:13 AM.
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10-12-2012, 06:01 AM
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the 1.6 rockers might be to TRICK the factory ecu..
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10-12-2012, 06:27 AM
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I asked comp cams and it it's answer to use this rockers...And I boght it
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10-12-2012, 06:35 AM
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Quote:
thanks for man...yes I plan to use the car for daily use...spically high ways driving.....the heads are stock and not decked...but the piston !!I already bought it and bored the block on it.......I didn't want that in in the beginning but some tells it will burn much fuel.....so is there any suggest without replacing the piston?
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10-12-2012, 08:15 AM
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350 TBI first time rebuilding engine...question
Did you buy the pistons from Summit Racing and are they still in the box? Summit Racing will swap the pistons as long as they have not been installed on the rods. These are the pistons that are needed Keith Black/KB Pistons 9902HCKTM030 - Keith Black KB Performance Claimer Piston and Ring Kits - Overview - SummitRacing.com There is no way to use the pistons that you have. They have hollow domes that cannot be machined down. I feel bad for you being in this situation but you should have came here before you ordered any parts. You are saying they recommended that camshaft K12-365-4 and the 1.6 rockers. With the pistons you have the compression is so high you would have to use reace gas (110 octane).
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10-12-2012, 08:29 AM
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How did you calculate your pushrod length?
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10-12-2012, 09:22 AM
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10-12-2012, 09:25 AM
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I use a head a thick gaskit 0.045in do you think this will help??it's diffecult to return the piston cos I already open it and it get some dirt
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10-12-2012, 12:09 PM
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350 TBI first time rebuilding engine...question
Looked on Summit Racing at the head gaskets for a 93 350. The compressed thickness is .041. This would give you a Static Compression Ratio of 10.562 and a DYNAMIC EFFECTIVE COMPRESSION RATIO of 8.790 which cannot run on 93 octane gas with a set of iron heads without detenation. You have a TBI system which is computer controlled. I can see the computer trying to reduce the timing because of the knock sensors. Getting somewhere around 6 miles to the gallon of gas because the timing is retarded so much. I would try and clean the pistons up with some degreaser (Simple Green). Mix some Simple Green with hot water to clean them and dry them immediately to prevent spotting or turning white. If not maybe you can sell them later. But you definetely need the 9902HC pistons if you want to use this motor for the street. Maybe someone else can come along and give you some better advice. Good luck.
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10-12-2012, 01:21 PM
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Quote:
Compression, you didn't sight what head you've got if original the 1993 TBI engines use the Swirl Port head, these are not very high RPM heads as the vane that creates the swirl obstructs the port preventing revs over 4500 RPM regardless of the cam used. The Swirl Port head comes in two casting with different size chambers the 14102191 has a low compression 74cc chamber while 14102193 has the high compression 64cc chamber. So before you bought pistons you needed to pull a rocker cover to find the casting number of the heads on your engine. A 12cc domed piston is likely to cause compression ratio problems with a super tight tune and iron heads with 91 octane fuel about 9.5 to 1 Static Compression Ratio (SCR) with a mild cam is about as far as you can go without encountering detonation. Go here when you know what head you've got <<< United Engine & Machine Co. Incorporated >>>. Pushrod length is determined by how the roller on the rocker tip traverses the valve stem tip; you can't determine this till the engine is assembled up to the and including the heads. Then with an adjustable pushrod you place a mark on the stem tip and turn the engine over by hand to get a witness mark of the roller on the stem tip, using this technique the proper mark will determine the pushrod length. Changes in build up from block decking, head milling, head gasket, stack-up changes of the type and manufacturer of heads and certainly changes to roller rockers will affect the needed pushrod length. Follow the instructions found here >>> COMP Cams® - Sorry... >>> The SCAT stuff is cast or forged in China and finish machined in the USA and is priced likewise. Most of the high priced brands are also made in China and finished here but are sold at made in America prices. The SCAT stuff is damn good stuff we use a lot of it from street rods to full up race engines. I happen to like and use the SCAT 2-ICR5700 for 5.7 inch rods and really make use of the 2-ICT6000 6 inch rod, these are made from forged 4340 and use capscrews rather than bolts. They are plenty good for hot street engines and Claimer race motors. Capscrews make for a stronger rod as the compromises made in the shape of the shank to allow a headed bolt are avoided. The capscrew rod also gets around the issues of clearancing for a stroker which compromises the bolt head. These rods use a capscrew that passes through an alignment dowel that insures the cap and shank make properly, they also provide an extra step outside the fine-line of the cap and shank interface which is a great help in reacting the tension loads put on the cap when the rod assembly is jerked down on the intake stroke. This is a movement that wants to egg shape the cap which pinches it in at the interface line with the shank. This movement pinches the bearing taking the oil wedge off the rod journal, spinning the bearing and finally failing the rod. the design that SCAT uses along with the capscrew mounting hardware goes a long, long way toward eliminating this most common of rod failures. A bushed rod with floating pins is the only way to go. This eliminates making mistakes disassembling and reassembling pressed pins that can bend and twist the rod and in the case of alloy steels like 3140, 5140, or 4340 unlike the factory mild steel of 1046 or 1053 the alloy steels do not like to be heated and many shops heat the pin end because this is fairly safe to do with mild steel, but with alloy steel it's a disaster in the making as it modifies the molecular structure and destroys the heat treatment of these materials. Stay away from 5140 rods, this stuff is advertised as having the same tensile strength as 4340 at a lower price. While this is true there’s more to the performance of a chunk of metal than its tensile strength. In the case of 5140 it is brittle compared to 4340, refer to the Izod Impact Test numbers for these metals, For a connecting rod where the load constantly changes from compression to bending to tensile and repeat again a more brittle material is asking for trouble. 5140 is OK for a crankshaft when running an automatic on one end with an expensive/effective damper on the other. Unfortunately, you've made some really big decisions before coming here first and you have stuff like the pistons that in the first place aren't a good street piston and secondly have defined the rods and crankshaft for you. Actually the best way to get power out of a TBI engine is to make it bigger a 383 being the way to go, use less cam, use a 670 CFM TBI from an older mid 80's to mid 90's 454 or get a new one from Holley and use a custom chip with the higher manifold vacuum that comes from the milder cam. This makes a much more stable and predictable engine. For about the same cost as what you've sunk this would have been a lot less painful. Now you've got these pistons which have you locked into the 5.7 inch rod. Short of sending this stuff back I don't know what you're going to do about compression especially if you've got 193 heads. The other way to get more power out of the TBI engine is to replace the heads. The Vortec is always a good choice for these. This type head gets much better power by improving the burn rather than using more fuel and air to burn. This again lets you get away with a milder cam and fewer, if any, changes to the injection programming. Against the very mild OEM cam that the TBI engines use the Vortec head will pick up an easy 20 horses. Given the Edlebrock 3702 cam that will go to 30-40 horses with a like amount of torque increase in both cases. These do get you into some plumbing headaches with the EGR which are not too difficult to solve or with a custom chip the EGR can be eliminated. Don’t just disconnect it as this will cause the mixture to go lean more than the LEARN function in the computer can compensate for and you may just toast the engine as a result. There are aftermarket Vortec type heads from many sources in iron and aluminum. For a mild 350 these from Skip White are pretty decent and let you use your current intake <<< White Performance Detail Description >>>. Frankly, I’d send everything back and completely rethink this project and certainly come here for advice. Bogie
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10-12-2012, 01:44 PM
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Listen to Bogie; print that post out and keep it, ask questions untill you UNDERSTAND it. Don't be the guy who comes here with his Killer Engine Of Death; and when we give him sound advice about problems he WILL have; because he doesn't have the experience needed for the performance he thinks he wants, he gets all internet-mad and argues with us because WE are wrong. Usually that guy just wants us to pat him on the head and say 'nice job sport!' regardless of how much of a Mongolian Cluster-eff this will be. These are the people who got trophies in youth league for showing up with their jockstrap in the proper place, and have never learned to overcome having a setback or being told 'No.'
You made a mistake; and the guys on the techline didn't do you any favors. We've all made mistakes, its okay. You're better off taking a week to rethink this. Comp is a joke when it comes to customer service. They tell you how to properly measure for pushrods and tell you how critical it is; but the drooling meth head on the phone, sells an uninformed guy pushrods, with a NON- OE rocker ratio. That ones not your fault. I see it too at my job. Guy calls up, orders an overhaul kit. Easy sale is to just punch the ticket and make money; but no, I take 20 minutes trying to figure out what he wants, what hes doing and if he can afford it. If he tears his muncie apart when he gets the overhaul kit, and he finds he needs 2 forks, all the reverse parts and his case has a bore that wont hold the countershaft without silicone; he's usually over his budget and now he's got an overhaul kit he can't use. I'll take it back, but hes gotta ship it and lose 10% for me to put it on the shelf, assuming he didn't lose all the little springs, etc. Its better to EDUCATE my customer, have him disassemble and inspect before ordering. Start a new thread: Tell us where you want to go; what your starting block is, dont even bother with the parts you bought at this point. Give us a reasonable budget for the motor, and what you want to do with it. You'll get a much better picture with a clean sheet rather than trying to erase all this stuff
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| The Following User Says Thank You to AutoGear For This Useful Post: | ||
Jaykobo (10-15-2012) | ||
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10-12-2012, 02:42 PM
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I just ran this cam in my last 383 TBI. Let me give you some quick specs of what i did. I ran 454 injectors around 16psi, 50mm TBI, and a matched Edlebrock 3704 50mm intake. I ran the same cam with Trick flow 1.6:1 narrow body rockers. I had KB 135 pistons i believe with a Trickflow 23 degree 195 cc runner heads with 64cc combustion chambers. Was a 383 scat setup. I had Brian custom tune me a chip took about 3-4 tries to get it dialed in via datalogging. Engine ran really strong did start losing power past 5000 but the bottleneck was in the 2bbl TBI setup so a standard 4bbl intake with a TBI adapter would have been an upgrade with the EGR tuned out of chip. Unfortunately after 2 oil changes i went to synthetic and the cam went flat really quick so now i sold the shortblock and have the heads and TBI stuff in garage collecting dust. So word of advice the cam can be run but with the appropriate heads and valvesprings and break in is crucial and always run with zinc additive. I would really recommend you look at the 8-304-8 roller cam and stay away from flat tappet cams. I was running 9.6 compression with the pistons in the hole .006 and a .039 gasket. Hope this helps some.
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10-13-2012, 09:24 AM
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I belive now that I was trying to build the engine with a blind eyes and tight brain....I think I was easy. I already check the heads and the #14102193 which have a high comperssion and 64cc head chomber. I read the instruction of the -14 cc and it required 2-4 dgreeing less timing. I now make a mistake and want to correct the stuation now.want your help guys. the most important and hard quiestion to me.......will the engine run with this piston or not......need more dgreeing for less compession ratio?I just read on the net pages that. I will try to buy the 2inches intake and I read on google that you can bore the stuck monifold and just buy a 454 thottle body for more breathing...is it ok? the chip....I know about it but like to hear which is recommended for the use? with intake I think I need headrs exhust. and I,m a little shy about asking....I think I asking much...be pationt with me the engine is now for racing use??can't be used on high ways?the normal octan here in my country is 95 will it work well or need to increase it? I won't run a high RPM......mixmum 4000 please recommend the parts needed to correct my mistake.....and would like to thank you guys for all answers
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