Thoughts on my new motor build

[sav300]

I am currently rebuilding a 71 Chevy 2wd long box with a new powerplant. It came with a stock 350 and here is what I've done so far.

Bored .030 over
Edelbrock Performer Intake
Keith Black Hypereutectic Pistons(10.2:1 w/ 64cc heads)
305 Heads(port and polished)
Edelbrock Performer Cam(No clue why I bought this, but I am going to upgrade once the motor is broke in. Lunati Voodoo to come.)
Scat 6" I Beam Rods
Forged Eagle crank
Edelbrock Double Roller Timing chain
Rochester 700CFM Carb
Flowtech Afterburner Headers
2.5" X-pipe exhaust with Flowtech Afterburner Mufflers
3.73 Gears
TH350 with 2800 stall

I plan to upgrade to Trick Flow or World heads with 58cc-64cc combustion chambers and 2.02 & 1.94 valves. Along with the Lunati Voodoo cam.

Hoping to make a good street/strip pickup. Tell me what you think!

Thomas

[Marv D]

Your putting a lot of $'s into the bottom end to be choosing a hypereutectic piston. If your going to all the trouble of a 6" rod, and not doing a forged piston,, I'd question why????

I'd also suggest you get the heads you want, (the 305 heads on a 350 deal just kills me) And get the cam you want and break the motor in right, with the parts you want. Circulating trash through the engine for a second cam break in really sounds counter productive to me.

Sounds like your looking for a decent street performer,, brand aside, I'd suggest a 1-5/8" long tube header MINIMUM.

Of all the head choices out there today,, TFS would be one of my LAST choices,, but that's all just my 2¢

[sav300]

Originally Posted by Marv D

Your putting a lot of $'s into the bottom end to be choosing a hypereutectic piston. If your going to all the trouble of a 6" rod, and not doing a forged piston,, I'd question why????

I'd also suggest you get the heads you want, (the 305 heads on a 350 deal just kills me) And get the cam you want and break the motor in right, with the parts you want. Circulating trash through the engine for a second cam break in really sounds counter productive to me.

Sounds like your looking for a decent street performer,, brand aside, I'd suggest a 1-5/8" long tube header MINIMUM.

Of all the head choices out there today,, TFS would be one of my LAST choices,, but that's all just my 2¢

I understand where your coming from. I got the hyperuetectic pistons becuase I have them in another motor that I build and they have been flawless. Yes forged would be better, but for $150 brand new with warranty I couldn't pass them up. As for the cam I can see your point, but with the parts I have available I'm going to try them out. Granted I do not care for 305 heads either due to their flow, but having the Edelbrock cam in it they will flow enough. Also the headers are 1 5/8" but I'm considering 1 7/8" primaries instead.

I'm just going to give this a shot for the time being as I have seen builds that I would have done differently that turned out to be quite reliable and adequate for what they do. During the spring I will order the new aluminum heads and cam(changing to hydrolic roller instead).

What heads would you reccomend?

Thomas

[ripdog28]

Umm, where to start. Marv is an excellent source of info for one so listen to him. Second, i dont care what cam you have those heads are no good and will not flow enough unless you want 200hp. Third, why would you have small heads but go with 1 7/8 headers? makes no sence. Bigger headers do not make more power they decrease exhaust velocity. Also, a bigger cam (Voodoo) will not help you with those heads. You have small heads with a big cam and it does not work.

[ProStreet71]

Agree with all above. Flat tappet cam break-in is scarey task now days. It seems you have about a 50/50 chance of cam survival, not to mention potential bearing failure from a cam breakin failure.(or worse) So why do it twice?

1 7/8 headers?!?! That is way too much header for your app. Even 1 3/4 is too much IMO. Stay with the 1 5/8.

[ProStreet71]

Oh and as far as heads, the Trick Flows are pretty good pieces. I would not reccommend World Products. Not that they are bad, but they arent that good either. I personnaly like AFR's. But they arent the be all end all. You really cant go wrong with any of the major brands. Profiler has a really good sale right now for an aluminum 195 or 210 cc head thats only like $825. Dart and Brodix are great also.

I would go with a 195-200cc head, Eddy Performer RPM air-gap, and the 1 5/8 headers.

[tomtuna1978]

sounds like you just want to get running and then upgrade the heads/cam later. wich is fine. as for heads .... id look at afr ( i think its a 195cc intake port head, wouldnt go bigger than that), or id even look at the gm fast burn heads(aluminum vortecs with better ports/chambers/valves). what ever cam you choose, call the company and tell them your combo, and they will tell you the right cam/lifter/spring/rocker package(get the springs they suggest !) for your ap. whats your hp goal ("Hoping to make a good street/strip pickup" can meen a lot !) ? and i wouldnt spray it more than a 150 shot if your gonna do nitrous. i would also think the 1 5/8 in. headers would be fine, unless your gonna sprey it or put a blower on it. and i know the price of those pistons was good and all, but its a shame you didnt get forged ! could of gon further with this combo ! what piston rings did you go with ? some gapless rings would be good also if you didnt get rings yet. and what oil pump ? a stock one is all you need ! ... just my 2 cents good luck with the build and keep us posted !

[Marv D]

Here's why I don't like hypereutectic pistons. This piston was not extracted from the motor, it disintegrated into a billion grains of sand. Difference between a $150 super deal on a hyper piston and a $500 Mahle, or SRP forged piston sounds like $350 worth of insurance something like this isn't going to happen to your investment.




Out of the box, no 'additional' work, bolt em on and make GOOD power... my preference is AFR. For a 350 keep runner under 200cc, put lift up a high as you can make with whatever cam/rocker you have available. Closer to .65 lift you get the more power you will make.

[BossHogg69]

I would wait until spring, do it all once with the parts you really want and save yourself time and money.

[sav300]

Ok so after some second thoughts I will agree with most and just wait. I was looking to compare the difference of the heads, but I think I will hold off on that and possibly use the set of fast burns I have. They have 58cc combustion chambers and I dont recall the valve size nor the flow.

Buying new heads is fine too, and most of you have built something with more power than what I'm dealing with so give me your best thought on a set of heads. And while your at it mention a specific cam if you do not agree with the Lunati. I'm always up for different options!

Thanks,

Thomas

[Super73]

Ok, it is my belief, (general rule here) the better the heads flow, the less duration you need in a cam to achieve the same amount of power of a less head/bigger cam combo (assuming port volume is the same). How ever, valve event's will still dictate where the power is made. Flow ratio also comes in to play. Lifting a valve to Marv's point, allows you to use more of the heads flow at given lifts.. IE the faster it lifts, the more time it's spent at .300+ filling the cyl more efficiently, the higher it lifts, the more time spent at max flow on the head. There is more to it than that, but with out writing a book (or reading one that's already written) it's not worth totally getting in to.

With that being said, choosing a cam with out knowing what heads you will be running and what your goals are, will prove to be dificult to do.

[tomtuna1978]

what super71 said !!!!

[hotrod 80]

First off are we building a 6" rod 355 or a 6" rod 383 ? I guess the assumtion is 383 ? Oh Hyper pistons are worst than cast IMO .

[ripdog28]

You have fastburn heads and wanted to go with 305 heads? Use the fastburn man.

[hotrod 80]

Fastburns are 62 CC chambers 210 CC intake runner . ZZ4 heads are 58 CC corvette heads.

[sav300]

Originally Posted by hotrod 80

First off are we building a 6" rod 355 or a 6" rod 383 ? I guess the assumtion is 383 ? Oh Hyper pistons are worst than cast IMO .

Building a 6" rod 355. Also my heads are from an 88 corvette, 58cc combustion chambers with 1.94 and 1.50 valves. Since I have time before the season starts up I might see if I could shop around for a different pair of heads that are decently price with what I need. As for the cam, well I'm not sure if summit will let me return it and get the correct one, but I will look into it.

And I can clearly see that Marv had one heck of an issue with the Hyper pistons, but what am I missing that makes them so bad in your eyes? I know they are in no way better than forged, but I ask due to another 355 I have. It is in an 84 chevy 4x4 with stock crank and rods (all blueprinted) corvette 58cc heads, and KB hypereutectic pistons. The motor has about 20,000 miles on the rebuild and went through one cam (number 5 intake lobe and lifter was destroyed). Before switching to a less agressive cam, I had a healthy one in her, the pistons have withheld 6,500RPM shift points and 110 Octane for this long. It's my daily driver that gets to see the track occasionally and I haven't had an issue yet. Did I get lucky or whats the deal???

Thanks for all your input so far guys.

Thomas

[Super73]

fyi.. I have had things from summit for over 9 months and returned it new in box, no questions asked and no restocking fee..

[hotrod 80]

And I can clearly see that Marv had one heck of an issue with the Hyper pistons, but what am I missing that makes them so bad in your eyes?

The content of silicone above the soluble 12% makes them brittle . I'll try to explain it . Hypers are cast pistons . Think like Iced tea . You can add sugar to the iced tea and it will mix till it is saturated with sugar , at some point the excess sugar just goes to the bottom of the glass . For a piston that is around 12% silicone . Hypers are above 12% , say 16% They are ok for stock rebuilds to tighten up clearences to help with blowby and piston noise , but i along with Marv have had bad experiences with them and will never use them in a performance application again . This is my opinion and i tried to explain it the best i could .

[Camaro_nut2001]

My opinion would be to check into a set of Ross pistons and if you don't care to sell your current intake then invest in a set of Vortec heads and intake and do a small amount of port work to them. I think that would be the cheapest. JMO

[sav300]

Originally Posted by hotrod 80

And I can clearly see that Marv had one heck of an issue with the Hyper pistons, but what am I missing that makes them so bad in your eyes?

Hypers are above 12% , say 16% They are ok for stock rebuilds to tighten up clearences to help with blowby and piston noise , but i along with Marv have had bad experiences with them and will never use them in a performance application again . This is my opinion and i tried to explain it the best i could .

Well hotrod 80 you explained is well enough for me. Now I am a little nervous on this rebuild. I guess since the pistons are mounted on the rod, and they are press fit, this will be a live and learn motor. I'm not new to the sport, but I haven't built too many high performance ones like so. Well guess I can build it right, minus the pistons, and give her a shot!!

I'll keep you updated on the build and post some pictures or videos when I get the chance.

Thanks for your help and input.

Thomas

[Marv D]

Like said,, there are a few misconceptions in piston choices and popularity,, as the same goes for cranks, rods, and most everything else. Did you know MANY racers that use nitrous would much rather have a cast crank than a forged one. Reason being a cast crank is more forgiving and will 'flex' when it is hit with massive loads of pressure from the nitrous hit. A forged crank is HARD, BRITTLE and RIGID. It won't take flexing like cast,, it cracks. Don't read that wrong, few building a serious nitrous motor would consider using anything less than a true non-twist forging. BUT they would love to see the strength of a forged crank, with the flexibility of cast / ductile.

Now lets talk about pistons in the same light. Think of a hypereutectic piston as made out of Pyrex. We've all dropped mom's Pyrex bowl or dish and seen it turn back into the billion pieces of sand from whence it came. The hypereutectic alloy is just as brittle. (see picture above,, we found NO piece of the piston that was recognizable as piston except a small piece around the piston pin laying at the bottom of the pan) Hyper pistons shatter beyond comprehension unless you've ever pulled a head and seen carnage like that. That was NOT a nitrous motor. It was a normally aspirated 10.7:1 small block that was shifted at 6000-6200 rpm. The motor came apart at the 1-2 shift. What went first, the rod or the piston,,, I have my suspicions but it doesn't matter. WHERE is the piston???? If the piston was still there to guide the rod up and down the bore, maybe it wouldn't have gone through the side of the cylinder???

Now think of dropping a plastic bowl. It's soft, deforms, bounces and springs back,, won't take a lot of abuse before it crushes, but WILL take a lot of shock loading before it fails. That would be like a cast piston. You over do a cast piston and it WILL fail,, no doubt. But you miss the tune a little and it will survive, unlike the hyper that went south at the first hint of detonation.

Obviously the forged piston is like dropping a stainless steel bowl,,, it will dent your toe and the soft vinyl flooring before it cracks! We all know that so we won't even go there.

That's about as simple as I can state it. Something we all have done and can relate to. Hopefully not too simple as to sound stupid or condescending,, just trying to explain the strengths and weakness's of the different materials.

NOW,,, Thomas is talking about a KB hyper that 'ADVERTISED' 10.2:1 compression with a 64cc head. 10.2 with a iron head is risky with today's fuels,,, see picture above and remember, that motor ran Sonoco 102 motor octane fuel.

Also be VERY cautious in believing the 'advertised' compression on any site or from any manufacturer. How do they know what your deck height is?? how do they know if your going to use a 0.015" steel shim head gasket, or a 0.045" cheep builders composite gasket??? If you don't think that little 0.025" here and the 0.020" there doesn't add up to BUTTLOADS of compression you didn't know you have,, your fooling yourself. NEVER believe the advertised compression ratio MEASURE EVERYTHING your self (or have the machine shop do it) so you KNOW what your ending up with. Also did you know MANY of the KB pistons drop the piston as much as 0.040" down the hole. If you have a 0.025" normal deck clearance, and add the 0.040" from the KB compression height, and ALSO add the 0.040" for a normal FelPro composite head gasket,, you have a 105 thousands quench. I promise you that is going to be a detonating mutha with with that kind of quench. And let's not even discuss stacking all the errors in the other direction and ending up with a 11.8:1 motor that we thought was 10.2, and not feeding those hyper pistons enough octane.

End result is we have the potential to mistakenly throw a little detonation at the hyper (/ Pyrex) piston and near total engine destruction is the result. I'd MUCH rather throw $600 at a set of pistons and know I had a stable platform for as much power as I ever wanted to throw at them,,, than save $350 that could cost me 100% of all the rest of the investment.

That's my 2¢... but Thomas you sound like you have already made up your mind onthe build. And you SHOULD build the motor the way you want, can afford, or feel is right for you. I'm not saying if you use hyper pistons you WILL have carnage like the pic,, I'm not saying KB is junk, I'm not trying to do anything but offer some hind-sight in hopes it might help someone avoid some costly damage because they had never heard of the issue. That's all.

[hotrod 80]

Originally Posted by Marv D

That's my 2¢... but Thomas you sound like you have already made up your mind onthe build. And you SHOULD build the motor the way you want, can afford, or feel is right for you. I'm not saying if you use hyper pistons you WILL have carnage like the pic,, I'm not saying KB is junk, I'm not trying to do anything but offer some hind-sight in hopes it might help someone avoid some costly damage because they had never heard of the issue. That's all.

I also feel the same way , build the motor the way YOU can afford and think it should be built . It is your motor . I have my favorite brands and am not advertising , you ask for thoughs and opinions on your build . Im just giving my opinion .

[sav300]

Originally Posted by Marv D

That's my 2¢... but Thomas you sound like you have already made up your mind onthe build. And you SHOULD build the motor the way you want, can afford, or feel is right for you. I'm not saying if you use hyper pistons you WILL have carnage like the pic,, I'm not saying KB is junk, I'm not trying to do anything but offer some hind-sight in hopes it might help someone avoid some costly damage because they had never heard of the issue. That's all.

Well Marv that is about the best way to sum up my entire situation with as much detail as possible. That I thank you for. And after getting such feed back with this motor I am going to ask way ahead of time. I have a 67 Chevy 2wd short box that will be street leagal, but will only see the track (unless it's going to the local show). It has a 327 in it that is bone stock and I would like your thoughts ahead of time. Plan to keep the TH350 for a tranny, but my goal is 600-700 ponies. I do have an 8v71 that I could mount on it, but I really like good oldfashion NA.

Whats your take?

Thanks again,

Thomas

[Marv D]

600-700 n/a from a 327 is going to take a comp-eliminator budget ($30-40k range from drain plug to aircleaner bolt) I'm not even going to comment on the forced induction as that's not my thing. many MANY guys here WAY better versed in forced induction than I. Let's hear from them.

600 n/a SBC is about as easy as picking up the phone these days, but base it on a 400 block and you will be WAY ahead of the game and on your way to 700. 700 starts getting into your pocket pretty deep, especially when your limiting yourself to the small cubes. For my money a 302, 327 or even 350 is something that you only consider because of a nogalsta thing,, or to fit in some specific class rule. When you can order a Dart SHP block for $1300, and a 434 rotating assembly for around $1200,, you have a STOUT 700hp platform that won't take massive RPM's to get there. Add a set of the new Brodie STS 233 cnc heads for around $2200 and 700 is as easy as .7 lift and 6200rpm.

But,,, you asked about 327 so......

In the end only ONE THING will make n/a power,, HEADS. Pick a budget for heads, then double it. And seriously,, this is one area that the worn out old thing of 'speed cost, how fast do you want to go' really applies. I've got a set of 23° AllPro's that I have just over $7k in,,, for 800 n/a HP. Then maintenance on those heads is an issue too. Springs, rebuild the rockers and new titanium valves every other year brings an average of around $1000 - $1500 a year in head maintenance (not counting oil, bearings or anything else for the motor,, just HEAD MAINTENANCE)

To make that kind of power with a 327 n/a is going to take RPM. So you better build a bullet proof 9000rpm rotator. Like I said,, it's starts getting in your pocket REAL quick. Ask any of the quick guys here sending these 3500+ pound trucks into the 9's,, and especially any doing it with a small block what their maintenance budget is. It may have you reconsider the goals, or the platform. There comes a point (gasp,, I can't believe I'm saying this) but you would be WAY better off with a pigblock,, I mean BIG block <grin>

[ripdog28]

BBC Marv,