help building SBC for 79 vette
11-14-2013, 04:00 PM
#1
help building SBC for 79 vette hey, looking for some advice on a build i am piecing together and also some Q's answered on some things i dont know. i bought a 4 bolt main iron block 350 and a 700r4 and im looking to transplant it into my 79 vette, however before all this i want to build up both motor and transmission for some nice power. originally was going to go with a roots blower but for the power i want, which is somewhere around 400 to the rear, not really concerned that much with dyno numbers i just want a fairly quick motor for this vette.
anyways no more blower, im going to bore the motor out to a 383 and go N/A and (maybe) throw some nitrous at it much later. but from there i have a few questions.
i like edlebrocks perfomer RPM intakes, but if i purchase one for a 350 will boreing the motor to a 383 change anything so the intake wont fit properly anymore?
same question but for heads, also looking at a pair of edlebrock heads but again if purchased for a 350 will they fit the motor after bored out to a 383?
as far as the specs of the heads go, looking to make a heads/cam motor so i know raising the compression ratio will increase power and torque, but im unsure what specs to look for. combustion chamber, intake runner and exhaust runner. if someone could explain this better so i cna make a good selection.
cam choice, i know that heads and cams should be matched to each others strengths and weaknesses so the above question cant be fully answered without knowing a cam choice. right now i have none picked out as all im used to is ls1 cams. id like off-idle power and torque all the way up the rpm range, a nice performing cam with a nice sounds at idle, i dont need some monster loping cam but something good.
piston choice, i know these will definitly need to be bought 383-specific, but as far as which shape and specs to look for im lost. i know dish pistons are good for lowering comp ratios and good for boosted applications, so i think i need flat top or dome pistons to raise the ratio for a N/A build. i head also dome responds well to nitrous. any input to this question would be appreciated.
pushrod length. not really sure what i should be looking for here. at all.
rockers. my stockers are beat up and going to replace them, but the ratios dont make sense to me (1:6, 1:7, etc.) if someone could explain what i need to look for
distributor. only had one and never tinkered with it. i assume just get a good rated one for a SBC and be done with it? idk
Carb. again only had one and never messed with it. i understand CFM flow but i dont know how big a carb i should get. i know too small CFM flow will choke the motor but too big will not help either. again, input is needed. also not sure how much this matters but i have a 700r4 tranny. this tranny was in the vette when i got it and i heard with a 700r4 there was something special that needed to be done or not done with the carb, i forget i think it was a kickdown panel or something. anyone heard of this?
so yes its alot and theres alot i dont know about SBC lol. i know this is long but if anyone can answer at least a few questions it would greatly help me identify the specific parts i need. input and advice is greatly appreciated.
anyways no more blower, im going to bore the motor out to a 383 and go N/A and (maybe) throw some nitrous at it much later. but from there i have a few questions.
i like edlebrocks perfomer RPM intakes, but if i purchase one for a 350 will boreing the motor to a 383 change anything so the intake wont fit properly anymore?
same question but for heads, also looking at a pair of edlebrock heads but again if purchased for a 350 will they fit the motor after bored out to a 383?
as far as the specs of the heads go, looking to make a heads/cam motor so i know raising the compression ratio will increase power and torque, but im unsure what specs to look for. combustion chamber, intake runner and exhaust runner. if someone could explain this better so i cna make a good selection.
cam choice, i know that heads and cams should be matched to each others strengths and weaknesses so the above question cant be fully answered without knowing a cam choice. right now i have none picked out as all im used to is ls1 cams. id like off-idle power and torque all the way up the rpm range, a nice performing cam with a nice sounds at idle, i dont need some monster loping cam but something good.
piston choice, i know these will definitly need to be bought 383-specific, but as far as which shape and specs to look for im lost. i know dish pistons are good for lowering comp ratios and good for boosted applications, so i think i need flat top or dome pistons to raise the ratio for a N/A build. i head also dome responds well to nitrous. any input to this question would be appreciated.
pushrod length. not really sure what i should be looking for here. at all.
rockers. my stockers are beat up and going to replace them, but the ratios dont make sense to me (1:6, 1:7, etc.) if someone could explain what i need to look for
distributor. only had one and never tinkered with it. i assume just get a good rated one for a SBC and be done with it? idk
Carb. again only had one and never messed with it. i understand CFM flow but i dont know how big a carb i should get. i know too small CFM flow will choke the motor but too big will not help either. again, input is needed. also not sure how much this matters but i have a 700r4 tranny. this tranny was in the vette when i got it and i heard with a 700r4 there was something special that needed to be done or not done with the carb, i forget i think it was a kickdown panel or something. anyone heard of this?
so yes its alot and theres alot i dont know about SBC lol. i know this is long but if anyone can answer at least a few questions it would greatly help me identify the specific parts i need. input and advice is greatly appreciated.
11-15-2013, 02:22 PM
#2
..... ......
hey, looking for some advice on a build i am piecing together and also some Q's answered on some things i dont know. i bought a 4 bolt main iron block 350 and a 700r4 and im looking to transplant it into my 79 vette, however before all this i want to build up both motor and transmission for some nice power. originally was going to go with a roots blower but for the power i want, which is somewhere around 400 to the rear, not really concerned that much with dyno numbers i just want a fairly quick motor for this vette.
anyways no more blower, im going to bore the motor out to a 383 and go N/A and (maybe) throw some nitrous at it much later. but from there i have a few questions.
i like edlebrocks perfomer RPM intakes, but if i purchase one for a 350 will boreing the motor to a 383 change anything so the intake wont fit properly anymore?
No, all small blocks have the same external deminsions
same question but for heads, also looking at a pair of edlebrock heads but again if purchased for a 350 will they fit the motor after bored out to a 383?
They will fit.
as far as the specs of the heads go, looking to make a heads/cam motor so i know raising the compression ratio will increase power and torque, but im unsure what specs to look for. combustion chamber, intake runner and exhaust runner. if someone could explain this better so i cna make a good selection.
So many options that it would take pages to answer
cam choice, i know that heads and cams should be matched to each others strengths and weaknesses so the above question cant be fully answered without knowing a cam choice. right now i have none picked out as all im used to is ls1 cams. id like off-idle power and torque all the way up the rpm range, a nice performing cam with a nice sounds at idle, i dont need some monster loping cam but something good.
Same as above
piston choice, i know these will definitly need to be bought 383-specific, but as far as which shape and specs to look for im lost. i know dish pistons are good for lowering comp ratios and good for boosted applications, so i think i need flat top or dome pistons to raise the ratio for a N/A build. i head also dome responds well to nitrous. any input to this question would be appreciated.
You know to go 383, you have to STROKE andBORE it, not just bore.
pushrod length. not really sure what i should be looking for here. at all.
Unless you are going high port heads, stock length should work
rockers. my stockers are beat up and going to replace them, but the ratios dont make sense to me (1:6, 1:7, etc.) if someone could explain what i need to look for
That is the difference between cam lift and valve opening, for example, you have a .500 lift cam you are going to have .800 valve opening with a 1.6 rocker and .850 with 1.7
distributor. only had one and never tinkered with it. i assume just get a good rated one for a SBC and be done with it? idk
MSD
Carb. again only had one and never messed with it. i understand CFM flow but i dont know how big a carb i should get. i know too small CFM flow will choke the motor but too big will not help either. again, input is needed. also not sure how much this matters but i have a 700r4 tranny. this tranny was in the vette when i got it and i heard with a 700r4 there was something special that needed to be done or not done with the carb, i forget i think it was a kickdown panel or something. anyone heard of this?
Start in the 750-800 range
so yes its alot and theres alot i dont know about SBC lol. i know this is long but if anyone can answer at least a few questions it would greatly help me identify the specific parts i need. input and advice is greatly appreciated.
anyways no more blower, im going to bore the motor out to a 383 and go N/A and (maybe) throw some nitrous at it much later. but from there i have a few questions.
i like edlebrocks perfomer RPM intakes, but if i purchase one for a 350 will boreing the motor to a 383 change anything so the intake wont fit properly anymore?
No, all small blocks have the same external deminsions
same question but for heads, also looking at a pair of edlebrock heads but again if purchased for a 350 will they fit the motor after bored out to a 383?
They will fit.
as far as the specs of the heads go, looking to make a heads/cam motor so i know raising the compression ratio will increase power and torque, but im unsure what specs to look for. combustion chamber, intake runner and exhaust runner. if someone could explain this better so i cna make a good selection.
So many options that it would take pages to answer
cam choice, i know that heads and cams should be matched to each others strengths and weaknesses so the above question cant be fully answered without knowing a cam choice. right now i have none picked out as all im used to is ls1 cams. id like off-idle power and torque all the way up the rpm range, a nice performing cam with a nice sounds at idle, i dont need some monster loping cam but something good.
Same as above
piston choice, i know these will definitly need to be bought 383-specific, but as far as which shape and specs to look for im lost. i know dish pistons are good for lowering comp ratios and good for boosted applications, so i think i need flat top or dome pistons to raise the ratio for a N/A build. i head also dome responds well to nitrous. any input to this question would be appreciated.
You know to go 383, you have to STROKE andBORE it, not just bore.
pushrod length. not really sure what i should be looking for here. at all.
Unless you are going high port heads, stock length should work
rockers. my stockers are beat up and going to replace them, but the ratios dont make sense to me (1:6, 1:7, etc.) if someone could explain what i need to look for
That is the difference between cam lift and valve opening, for example, you have a .500 lift cam you are going to have .800 valve opening with a 1.6 rocker and .850 with 1.7
distributor. only had one and never tinkered with it. i assume just get a good rated one for a SBC and be done with it? idk
MSD
Carb. again only had one and never messed with it. i understand CFM flow but i dont know how big a carb i should get. i know too small CFM flow will choke the motor but too big will not help either. again, input is needed. also not sure how much this matters but i have a 700r4 tranny. this tranny was in the vette when i got it and i heard with a 700r4 there was something special that needed to be done or not done with the carb, i forget i think it was a kickdown panel or something. anyone heard of this?
Start in the 750-800 range
so yes its alot and theres alot i dont know about SBC lol. i know this is long but if anyone can answer at least a few questions it would greatly help me identify the specific parts i need. input and advice is greatly appreciated.
11-19-2013, 11:32 AM
#3
Not sure what heads you are looking at, but the Edelbrok heads in general are not great, would tend to be undersized for a 383 you should research this part of the build extensively. Definitely want the majority of funds for heads unless racing then bottom end too. Cam should depend on the engine combination and parameters in which you will use it, especially being it's an auto. Would also suggest a hydraulic roller. I believe you need to get the TVS set properly on the trans or it will burn it up. Pushrods, I would measure for the proper length. With an aftermarket head, unknown rocker pad height, pushrod cup, or valve length... along with gasket thickness and a block that may need decked you can't assume anything. Best to measure and get proper sweep over valve tip.
12-07-2013, 07:20 PM
#4
On The Tree
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As far as trying to find the right compression ratio. The only number on your head to look at is the combustion chamber volume. ex. 58cc, 64cc, 72cc, etc. bigger chamber= lower compression. Smaller chamber= higher compression.
12-07-2013, 07:59 PM
#5
Staging Lane
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hey, looking for some advice on a build i am piecing together and also some Q's answered on some things i dont know. i bought a 4 bolt main iron block 350 and a 700r4 and im looking to transplant it into my 79 vette, however before all this i want to build up both motor and transmission for some nice power. originally was going to go with a roots blower but for the power i want, which is somewhere around 400 to the rear, not really concerned that much with dyno numbers i just want a fairly quick motor for this vette.
anyways no more blower, im going to bore the motor out to a 383 and go N/A and (maybe) throw some nitrous at it much later. but from there i have a few questions.
anyways no more blower, im going to bore the motor out to a 383 and go N/A and (maybe) throw some nitrous at it much later. but from there i have a few questions.
Are you’re looking for naturally aspirated 400rwhp or was that the boosted goal? I’d say that it requires a much more serious first gen sbc than anything LS based to get there. The last two 23 degree head small blocks I had on chassis dynos were “middle of the road” builds.
4.000 x 3.75 (377 cic) 10.7 comp, IK 200 with some hand porting, hyd roller 24ish @ .050, RPM Air gap through a TKO600 in a ’67 Camaro. 348 RWHP (Dynojet)
4.030 x 3.75 (383) 9.7 comp, AFR 195, 233/241 @ .050 hyd flat tappet, RPM Air gap, through a T56 in a ’69 Vette. 327 RWHP (Dynojet).
Last year I built three more small blocks but didn’t bother to dyno them. I’ve pretty much given up on them for street performance.
I’m not trying to talk you out of building an early small block but if you want N/A 400 at the wheels, it takes some good heads and a lot more cam than an LS needs. Unless you have most of the parts on hand I think the cost just doesn’t make sense for what you get back from these older engines.
12-16-2013, 08:39 AM
#6
Staging Lane
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personally a 750cfm carb will do you fine. I run a stock dist with summit cap button and 8.5 wires. MSD used to make my car pop when I shifted, its a auto so I never knew why.
