Chevy 302 build for my z32 w/th400

[dr_hunt]

Thinkin about dart 230s. for now pry just double humps cuz i already have a set. they just need rebuilt.

 

If you get 'em ported and fitted with 2.02's and 1.6's they will work pretty good on the little motor. About as good as anything since the breathing requirements aren't as much with the small displacement. I have a set of 041's ready to go on the shelf. Ran them on a 406 sbc and they worked real well, but love 'em better on a little motor.

 

I think the 230's are alittle big for the small cubes. Just my opinion.

Edited December 26, 2009 by dr_hunt

[grumpyvette]

Okso you want a high rpm screamer, thinking about building,a 302 like the old Z28 engines?

well technology has advanced and theres better current options if your really interested

heres a mid priced effective combo

 

Ok time to get back to reality!

if your serious about building a high rpm screaming sbc I can,t think of anything Ive built or seen built that sounds better or pulls harder than a PROPERLY BUILT 377 , thats a 400 block with a 350 crank, it will spin at 7000rpm quite happily with a decent solid lifter valve train and the extra cubes more than compensates for the slight rpm advantage of the smaller 302.

a properly assembled 377 will easily exceed 500 flywheel hp and have noticeably more torque than a similarly built 302, and before you ask it should be rather obvious that the engine built like that requires a proper quench and some bowl & chamber work and un-shrouded valves and its very unlikey to run on high test without some octane booster

 

youll want a manual transmission and a 4.11-4.56 rear gear

 

heres a combo thats KNOWN to work

 

carb

http://www.summitracing.com/parts/HLY-0-4781C/

 

intake

http://www.summitracing.com/parts/HLY-300-110/

 

heads

http://www.summitracing.com/parts/BRO-1021001/

 

block

http://www.summitracing.com/search/?keyword=31161211&dds=1

 

cam

http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=00351&x=49&y=8

 

pistons

http://www.kb-silvolite.com/test/icon/icon.php?action=details&P_id=332

 

rods

http://www.summitracing.com/parts/SCA-26000716/

 

crank

http://www.summitracing.com/parts/SCA-435010/

 

long tube 1 3/4" tube headers that fit your application

 

a decent 7-8 qt baffled oil pan, that fits your application

 

http://www.moroso.com/catalog/categorydisplay.asp?catcode=11929

Edited December 26, 2009 by grumpyvette

[Firion__13]

I have been looking at these for a long time. He has alway got a set on ebay.

http://cgi.ebay.com/ebaymotors/Dart-Pro1-Platinum-230cc-Aluminum-SBC-Heads-L-K-Roller_W0QQcmdZViewItemQQhashZitem45ebc06690QQitemZ300307998352QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[dr_hunt]

That's a really really nice cam, have used it before and it really works well. I don't think he's got that kind of money to sink into a 12:1 race motor but I do think he's interested in his 302. Summit isn't that cheap of a place to buy, there are alot of places that have equal quality parts at cheaper prices for a combo deal anyway. cnc motorsports puts together nice combo's. Have bought from them before. Also Dave Poske out in Tennessee is another good place, very good if you have a problem, he races what he sells.

[dr_hunt]

I have been looking at these for a long time. He has alway got a set on ebay.

http://cgi.ebay.com/ebaymotors/Dart-Pro1-Platinum-230cc-Aluminum-SBC-Heads-L-K-Roller_W0QQcmdZViewItemQQhashZitem45ebc06690QQitemZ300307998352QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

 

Yeah, those are nice, but still alittle much for a 302 size motor, will be really lazy till about 4K with those heads. Remember TQ curve wins the race. Some 180 to 195cc heads are better suited for your application IMO.

[Firion__13]

thats true... but the SCCA motors is what im kinda baseing mine off of. they really didn't have much for torque. and they didn't make much for power till 5500. they were'nt a drag car thats for sure. The build sheet in my book says...

RPM HP TQ

5500 364 348

6000 412 361

6500 447 362

7000 475 356

7500 483 338

8000 501 329

 

They were knows for being sluggish at low rpm.

[Firion__13]

Doc you don't happen to know the stock cc intake size of the double hump heads do you?

[grumpyvette]

Doc you don't happen to know the stock cc intake size of the double hump heads do you?

 

 

most are in the 155cc-163cc range, and flow at less than 220 cfm in stock condition, untouched vortecs are superior to un touched fuelie heads, the question comes up frequently as to which, vortec or fuelie heads are best

both are not top choices by todays standards

it depends mostly on the condition of the heads,(remember fuelies are on average over 40 plus years old)and on both WHICH fuelie heads they are, and the valve sizes,if they are not 2.02/1.6(if your willing to do minor port, bowl and combustion chamber mods like un-shrouding valves) Id suggest going vortec.

and if your going to have the vortec compatible parts like valve covers, rockers, intake, etc. but in almost every case the VORTEC HEADS will produce slightly better power, unless you do those mods to the fuelie heads

 

typical reworked fuelie

http://www.kendrick-auto.com/462_chevy_head.htm

 

vortec

http://www.kendrick-auto.com/vortec_cs_gm_head.htm

 

keep in mind the average fuelie head has a smaller 155cc-163cc port than the typical vortec at about 170cc, and the higher port angle on the vortec heads flows better

 

http://www.purplesagetradingpost.com/sumner/techinfo/heads1.html#GM%20LT4

Edited December 27, 2009 by grumpyvette

[Firion__13]

Thanks vette. mine are pretty much all done. i bought them ported and polished, and they have the big valves. they are actually from a 327. they are bare at the moment though.

[dr_hunt]

Doc you don't happen to know the stock cc intake size of the double hump heads do you?

 

double hump heads came with 1.94/1.5 valves and 2.02/1.6 valves depending on hp level. Using what you have is what most hotrodding is all about and so is getting all you can out of it. It isn't all about buying parts sometimes as in the old days double humps, 292 turbo heads and the infamous bowtie heads were all we had. I built a 305 inch motor for a rail dragster that left at 8200 and shifted at 9500. Short lived but it was a screamer and all with chevy parts. It can be done and work well, maybe not as good as it would with aftermarket parts, but it'll be hard to beat with the right trans and gearing on any track.

[Firion__13]

double hump heads came with 1.94/1.5 valves and 2.02/1.6 valves depending on hp level. Using what you have is what most hotrodding is all about and so is getting all you can out of it. It isn't all about buying parts sometimes as in the old days double humps, 292 turbo heads and the infamous bowtie heads were all we had. I built a 305 inch motor for a rail dragster that left at 8200 and shifted at 9500. Short lived but it was a screamer and all with chevy parts. It can be done and work well, maybe not as good as it would with aftermarket parts, but it'll be hard to beat with the right trans and gearing on any track.

 

Hmmmm... tell me more

[HarrisonTX]

Grumpy, He wasn't asking for a suggestion on what motor would be better.

If you feel the need to give advice, and post a bunch a links, why not talk about a 302, since that's what he is building. I doubt he is going to scratch his whole build that is already at the machine shop.

Sure the 302 isnt a tourqe monster but who cares. Its a light car, and will still be fun.

I'm sure you will reply to this post with 4-6 links on why I am wrong, and what will be better.

[grumpyvette]

IVE BUILT OVER 100 plus SBC ENGINES FOR THE MUSCLE CAR CROWD AND A FEW CIRCLE TRACK GUYS OVER THE YEARS,if your goal is the least expensive engine that produces good hp the 350 or possibly a 383 is a very viable starting point as a 302 will cost more to build in most cases, yes you can build a nice responsive 302 sbc, and Im sorry you think Im trying more to dissuade him than give useful advice, Im really only using experience to suggest a route that in the long run will be less expensive,.... if you do this stuff long enough...you see trends.. you find that if you build a small displacement combo, the guys always come back, after consistently seeing the tail lights of their competition, asking what they can do, and the answer is always the same, you basically can throw a ton of money at any project or increase the displacement, because its simple physics

youll make about 1.2-1.3 hp and ft lbs of torque per cubic inch of displacement, using basically stock style components

 

302=377 hp

377=471 hp

Edited December 28, 2009 by grumpyvette

[dr_hunt]

Destroked 350 (3.0 stroke) Arizona hard chrome stock crank, aluminum rods, BRC pistons I believe 13:1 but been along time, pro ported 292 angle plug heads by reher-morrison, matching ported dual quad intake, carb shop custom carbs, Reher-Morrison custom grind solid roller cam, art carr custom converter, th400 trans w/trans brake in a 232" rail dragster.

 

You will find that the 302 really pulls hard on the top end. It makes more efficient use of production heads as the air flow requirements are significantly less, which is why the motors ran so hard as compared to say a 350 with the same heads. You will extract more hp per cubic inch out of a 302 with camel heads than you will a 350 IMO. IMO the camel heads are pretty well suited to the 327 and 302 engines for that reason. IME you can build a 327 and 350 identical with identical untouched production heads, same intake, and production cam and the 350 will not make enough hp to dominate the 327.

 

Pro ported iron heads will work well in that combination as will stock heads. Bigger flow numbers and port sizes aren't necessarily better on small motors as about anyone can tell you from experience. Putting big heads on a small motor will kill your low end and make a peaky motor just that much more peaky without really gaining that much hp on the top end vs dollars spent on the big buck big heads. Just look at the 305" sprint car motors and what heads they run from brodix vs lap times and you'll see what I'm talking about. It was all about reigning in the cost, not spending more as is the case here.

 

Saving money on a build that your happy with and will perform pretty good in a light street/track car will pay dividends in cost savings and be able to build it again down the road. It has been said to build the displacement you can afford and this seems to fit the bill. Grumpy has his points too, but in the end it's the owner that has to be satisfied.

Edited December 28, 2009 by dr_hunt

[HarrisonTX]

IVE BUILT OVER 100 plus SBC ENGINES FOR THE MUSCLE CAR CROWD AND A FEW CIRCLE TRACK GUYS OVER THE YEARS,if your goal is the least expensive engine that produces good hp the 350 or possibly a 383 is a very viable starting point as a 302 will cost more to build in most cases, yes you can build a nice responsive 302 sbc, and Im sorry you think Im trying more to dissuade him than give useful advice, Im really only using experience to suggest a route that in the long run will be less expensive,.... if you do this stuff long enough...you see trends.. you find that if you build a small displacement combo, the guys always come back, after consistently seeing the tail lights of their competition, asking what they can do, and the answer is always the same, you basically can throw a ton of money at any project or increase the displacement, because its simple physics

youll make about 1.2-1.3 hp and ft lbs of torque per cubic inch of displacement, using basically stock style components

 

302=377 hp

377=471 hp

 

He never asked for any advice on cubic inches, nor how to be the fastest guy in town, and win races. Im sure if he was, then he'd build a 572 BB.

You can throw around numbers all you want, this isnt a pissing contest. I'm not interested in how many SBC's you've built. Anyone can assemble a motor. Anyone old enough can assemble 100.

I'm just saying stick to the questions he is asking.

If you spent as much time advising people on their current builds as you did trying to change their minds 80% of the way into the build, we would all have trophies, and be in victory lane.

 

 

Dr. Hunt, that motor sounds awesome. I dont have a super expensive bottom end like that, but I'm paying close attention to the valve train on my 302. AFR's Baby!

[grumpyvette]

ok just a bit of info, if your looking for what we did years ago, when we were limited to ported fuelie and turbo heads

 

when we used to build 302 z28 engines in the past for street use we tried to build 11:1 cpr motors for the street, (we also built alot of .030 over size 327 engines)and the most effective cam we found after testing dozens back in those days

were these two, in the camaros and a few vega engine swaps

for a manual transmission and a 4.11-4.56:1 rear gear this was frequently used with good results, but we also ran edelbrock SY1 or cross ram dual quad intakes were the crane solid lifter flat tappet cams 114681 and the similar 110921, it was markedly more effective than either of the two off road z28 cams #3927140 or #3965724

in those days no one serious ran hydraulic cams, you would be laughed off the track, solid flat tappet lifters were your only real choice if you expected to buzz 7000rpm plus

 

a few years later we found that those same two cams gave excellent results in a 10.5;1 cpr 383 with a 3.73:1-4.11:1 rear gear and were even better once the aftermarket supplied the dart and brownfield heads, later

 

http://www.cranecams.com/index.php?show=browseParts&action=partSpec&partNumber=110921&lvl=2&prt=5

 

http://www.cranecams.com/index.php?show=browseParts&action=partSpec&partNumber=114681&lvl=2&prt=5

 

the 114681 had better street manors but it gave up a tiny bit of power

 

 

but keep in mind sunoco 260 high octane gas was 39 cents a gallon and available almost everyplace, if you knew where the sunoco stations were.

Edited December 29, 2009 by grumpyvette

[dr_hunt]

Looking good, your parts list that is, both of you actually.

 

Sunoco 260 was only a 102 octane gas, we used to get 115 avgas at our airport back in the days and we could get 100 octane premium at the pump. Ah, the days of cheap gas and good gas are gone, oh well.

 

AFR's are certainly about the best money can buy, what size are you looking at? What spec's are you looking at for the cam? Are you planning on running titanium retainers to lighten the valve train load?

 

On your h-beams, what rods did you buy or are going to buy?

 

Pistons?

 

Details my men, details. People are drooling already and bench racing the heck out of your combos.

Edited December 29, 2009 by dr_hunt

[Firion__13]

Ok ok ok guys... Vette i value your insight because you know what you are talking about you have built motors and you know what works and what doesn't. Do have have any recomendations on a cam that is for an 8000rpm redline something thats power range is 5000 to 8000?

Remember guys im not building this to be the fastest around, and im not trying to build it cheaply. so far all ive got mapped out is the bottom end... I decided today im gonna go with aluminum heads, and push it up to 11:1 compression. I said to my self,"self your not really building a street motor, why not go as far as pump gas allows?" I really need help picking a choosing what to do with my valvetrain, and heads. Im going for an 8k redline. Here is what i got picked out for the bottom end so far.

Crank- Eagle 4340 ESP Ultra-light #4348300057fw

3.00in storke and 1.889 rod mains

 

Rods- Eagle 6.250 H beams #CRS6250HJ

(honda) 1.889 mains. We use those small mains on all the race car motors we put together. I know the smaller mains means less longevity, but its only gonna get driven once a weekend or less. Also this combo will have a 13.89 degree rod angle which too i have been told will drop the longevity. The rod ratio is 2.08:1 and weight 540 grams.

 

Pistons- SRP Professional #271059

Compression ht 1.260 Dome vol 11cc Bore 4.030 Weight 442 grams

 

clevite berrings, ARP hardware, and a moroso oil pan.

 

So anyone got any ideas on heads and valvetrain parts?

[dr_hunt]

Build it light, wind it tight! I'd go with titanium valves and retainers with 10 degree locks. As for cam you'd probably be better off roller but some solid flat tappets do exist in your realm of rpm life. Isky 201561 in your motor will rev 8K+, 201630 and 201631 in solid roller will get you there also and make big big hp with good heads. I'd bet you'll be over the 500HP mark with either quite easily.

[grumpyvette]

ID usually suggest a shaft rocker system be installed on a valve train that was expected to exceed 7000rpm but to keep costs semi reasonable,a flat tappet solid lift engine cam like this, for your sbc thats designed to run up in the 7000rpm plus range

remember if the engines cammed and the intakes designed to operate in that 4000rpm-7600 plus rpm band the cars transmission and rear gear should keep the engine in that power band most of the time, so youll need to calculate the correct gear ratio

 

http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cylinders=8&Engine_Make=CHEVROLET&Year=1982&Engine_Size=262-400%20C.I.&partNumber=111411&partType=camshaft

 

http://www.cranecams.com/?show=browseParts&lvl=3&prt=122&action=partSpec&partNumber=99846-16

spring Requirements: Triple Dual Outer Inner

Part Number 96877

Loads Closed 126 LBS @ 1.850 or 1 27/32

Open 328 LBS @ 1.340

 

use 1.5 RATIO rockers,like these

erson 800-16

specs>> 1.5 3/8 $271.21

http://www.pbmperformance.com/store.php?catId=24

 

to reduce the effective ramp acceleration rate on the valve train

 

http://www.summitracing.com/parts/CCA-4013/?image=large

and a stud girdle on the rocker studs, seems to be indicated

 

and this intake so you won,t restrict flow rates

http://www.summitracing.com/parts/HLY-300-110/

 

decent low cost cast valve covers to clear the stud girdle

http://www.summitracing.com/parts/TFS-31511802S/

Edited December 29, 2009 by grumpyvette