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Topic Review (Newest First)
04-27-2011 07:11 PM
DoubleVision Interesting that you say that Tech, as I have guys ask me why I buy seperate parts now instead of kits even so it costs more. I tell them pay a little more now or a lot more later from parts failure.
04-27-2011 06:58 PM
techinspector1
Quote:
Originally Posted by cucumber1949
Tech, I see youíve recommended a valve kit, guide plates, studs etc for a similar setup in this thread - http://www.hotrodders.com/forum/hor...que-196916.html. Taking a closer look at those, these parts look compatible for what Iím trying to do but would appreciate your comment.
Never used 'em, but it sure looks like the hot tip to me. Two fellows on this forum brought them to my attention and I can't remember who they were. I even tried to look back in the posts and find where they recommended CP kits, but couldn't find it. It just makes a lot of sense to me to buy separate parts and fit them together yourself these days. You and I have a way better eye for imperfections than some assembly line worker, because he doesn't care.
04-27-2011 06:20 PM
cucumber1949 TechInspector1, thank you for the excellent analysis.

First of all, these are indeed flat-top pistons Ė no dish, just the 4 reliefs. What I didnít know was the correct relief volume when I used the CR calculator and I made an incorrect assumption and went too high. Using your figures, I come very close to your SCR, which confirms weíre on the same page here. Thank you again for helping to avoid a mistake.

Secondly, I also confirmed that 9.9 SCR (Wow!) with the 64cc head and concur it is too much for what I want to do with a street cam. I donít want to venture into the aluminum heads in this app either although the machine shop keeps trying to talk me into an Edel E-Street head Ė with a 60cc chamber Ė he didnít think the engine should be Ďordianaryí LOL!

So, in the RHS world it looks like the Pro-Torker 76cc head is a good choice in this app. I would think that continuing to use a thin head gasket (somewhere in the .020 area) would maintain about the same SCR I have now and allow adequate quench as well. I would still lean towards the smaller valves to facilitate the low end of the rpm range. High rpm ops are rare and not a factor, and anyway these small valves I currently have in the 487 heads are so gunked up that new heads and valves of any size could easily outflow what I have now, and Iím happy with the performance as it sits!

So, with bare heads, Iím still looking for recommendations on what parts to finish out these heads with.

Tech, I see youíve recommended a valve kit, guide plates, studs etc for a similar setup in this thread - http://www.hotrodders.com/forum/hor...que-196916.html. Taking a closer look at those, these parts look compatible for what Iím trying to do but would appreciate your comment.

DoubleVision Ė thanks for the recommendation on the cam. The cam that is in the car now does not show any wear that is excessive or indicative of an impending lobe failure. I really just donít know what it is and I havenít degreed it Ė I just know it is a mild cam based on the idle and vacuum Iím seeing now. My current thinking is if I was considering a new flat tappet cam, Iíd probably just leave the existing cam in it as it is adequate. Although Iím not looking for a performance gain from the cam, the benefit I see in a new (roller) cam is that I would finally know what cam is in the engine, and flat tappet break-in and wear issues go away. That to me is worth a few more dollars especially when Iím not far away from changing it out on the way to having the heads off.

GenY Ė thank you for the advice. Yeah, roller cams and lifters are pricey. I see the Howards cams Iím looking at goes for about $240 and their lifters are about $310 from Summit and they could probably sourced for a few dollars less. Itís still a significant bump over flat tappet prices but Iím feeling this is an area where I could justify it. Iíll take a detailed look at the specs on the Elgin cam if I can confirm the lifter spider retrofit.
04-26-2011 07:16 PM
techinspector1 Your current SCR is 8.80:1, using these values....
727.41 in the cylinder
78 in the chamber (heads always pour a little bigger than advertised
7 in the piston (assuming a perfectly flat crown with 4 reliefs. If you have those Fosdick stock Chevy pistons with the well in the middle like my photo below, then yeah, you're probably at 8.5 or so because I think they will pour 12 or 13. There is little or no flat area on the crown of those to generate squish, just that narrow ring of material above the ring package.
5.01 in the piston deck height
3.24 in the gasket.

Changing to a 12407 or 12410 or 12410-01 or 12410-02 with 64cc chambers (call 'em 66 for figuring the SCR), will net you 9.95:1 SCR and ruin the chance to use a short street cam. Moving to the standard Pro Torker 12402 or 12403 with the 67cc chamber (call 'em 69 for figuring the SCR) will net you 9.63:1 and will still preclude the use of a short street cam.

I really like the GM Vortec model of head that these guys produce, but you can only get them in 64cc chambers. Moving over to the Pro Torker, you can get 76cc chambers as well.

BARE HEADS

GM VORTEC - PRO TORKERô CYLINDER HEADS, CAST IRON
#12407 Pro Torkerô 23ļ GM Vortec, 170cc, 64cc, Straight plugs, 1.940" Stock Length intake valves, 1.500" Stock Length exhaust valves, 327-350c.i.

GM VORTEC - PRO TORKERô CYLINDER HEADS, CAST IRON
#12410* Pro Torkerô 23ļ GM Vortec, 170cc, 64cc, Straight plugs, 2.020" + .100" Long intake valves, 1.600" + .100" Long exhaust valves, 327-383c.i.

ASSEMBLED HEADS

GM VORTEC - PRO TORKERô CYLINDER HEADS, CAST IRON
#12410-01 Cast Iron, assembled, 170cc intake runner volume, 64cc combustion chamber volume, Straight plugs, 2.020" intake valves, 1.600" exhaust valves, Flat Tappet springs installed, 0.560" max valve lift.

GM VORTEC - PRO TORKERô CYLINDER HEADS, CAST IRON
#12410-02 Cast Iron, assembled, 170cc intake runner volume, 64cc combustion chamber volume, Straight plugs, 2.020" intake valves, 1.600" exhaust valves, Hyd. Roller springs installed, 0.600" max valve lift.

Dual bolt pattern (4 and 6-bolt) allows
compatibility with both early-style SBC
and GM Vortec intake manifolds.

BARE HEADS

PRO TORKERô 23į EARLY-STYLE SBC CYLINDER HEADS, CAST IRON
#12402 cast iron, bare, 170cc intake runner volume, 67cc combustion chamber volume, straight plugs, 1.94" intake valves, stock length, 1.50" exhaust valves, stock length. 327-350 cubic inches.

#12403 cast iron, bare, 170cc intake runner volume, 67cc combustion chamber volume, straight plugs, 2.02" intake valves, stock length, 1.60" exhaust valves, stock length, 327-383 cubic inches.

#12400 cast iron, bare, 170cc intake runner volume, 76cc combustion chamber volume, straight plugs, 1.94" intake valves, stock length, 1.50" exhaust valves, stock length, 327-350 cubic inches.

#12401 cast iron, bare, 170cc intake runner volume, 76cc combustion chamber volume, straight plugs, 2.02" intake valves, stock length, 1.60" exhaust valves, stock length, 327-383 cubic inches.
04-26-2011 06:14 PM
GenYnNC I 3rd the RHS Torkers, all the 1.94 headflow figures I've seen at 28" of water have been 10cfm higher at .500 than the 2.02 RHS Torker heads. The valve lifts under that have an even bigger margin. These are on real world flow benches and not from RHS (who tests with a 4.2" bore, weirdos?) . However, they do flow 240-250cfm. Remember, larger valve does not always equal "better" or more flow. It's all about port velocity.

If you are going to port the runners and under the valve job, then the 2.02's would be your best bet but I don't get the feeling you are going to do that.

Retro fit roller cam and lifters can get real expensive, real fast. I think the cheapest set of quality retro fit cam and lifters is like $550 from Lunatti...not 100% on that though.

I've never tried it but seems like I've read that if you can source a late model Gen I with the lifter spider, then you can run an 87-95 aftermarket cam... again, not sure. Might be worth checking out?

If you research it and go that route, here's some cheap goodies (American made also)

Here's an Elgin mild roller in the neighborhood you are wanting and only $189. Would match the RHS heads almost perfectly (considering their flow rates under .500 lift)
http://www.competitionproducts.com/E...uctinfo/E1136/

Set of Elgin OE roller lifters $119
http://www.competitionproducts.com/H...ctinfo/652416/
04-26-2011 04:21 PM
DoubleVision For your combo I too recommend the RHS heads. I would recommend the use of the 1.94 1.50 valves. Since you want to stay smooth idle, and high low end torque, then there is no need in spending the cash to convert to a roller when a flat tappet will do the job just as well as there really won`t be any power gain by going to a roller when it`s that small. going to the RHS heads alone is going to wake it up like you won`t believe.
This is the cam I`d recommend, it has a smooth idle and excellant torque and street manners:
http://www.summitracing.com/parts/CCA-12-206-2/
04-26-2011 07:44 AM
cucumber1949
Mild SBC top end upgrade

Looking to refresh the top-end of my SBC 350 in the T-Bucket. The 487 heads (1.94/1.50 valves) are showing signs of needing valve guides (sloppy) and I've already had each head off for a couple of leaking valves that were lapped in. Valves also show signs of leaking seals. I've been kicking the can down the road on these heads when it comes to fixing them properly because it looks like the money that it would take could be used to just about replace them with something better. I'll run these heads for the upcoming cruise season and then make the upgrade one of the winter projects. Bottom end is solid. While I'm at it, I'm thinking camshaft as well. This is a street T that has never seen the track and never will (won't pass tech).

Currently the engine is a Gen 1 3970010 block bored .030 originally out of a 71 El Camino. Flat top pistons with 4 d-shaped reliefs in the hole about .024" as I measured it the last time I had a head off. Currently using a steel shim head gasket and figure the SCR is about 8.5 or so with these open chamber 76 cc heads. Hydraulic flat tappet cam of unknown origin (could be stock). Currently running an Edel 1806 (650 cfm) on an RPM Air Gap manifold, 1 5/8" long tube roadster header into a 3" collector with tip mufflers. and an MSD 8360 distributor. Engine has an excellent smooth idle with good steady vacuum, great throttle response, accelerates very well (it's a T-Bucket LOL!), is a nice little cruiser and behaves well on the street. TH350 with a Hughes Performance flexplate and 2000 stall converter, 3.73 gears on 30" tires.

For the refresh, I�m thinking of upgrading to Vortec heads and a retrofit hyd roller cam that maintains the good idle and vacuum I currently have. Leaning towards some bottom end torque if possible. High RPM ops are not a consideration here, good street manners are important. I don't want to negatively change the personality of the car.

Here's what I'm thinking I'll use/need so far:

RHS cast iron Vortec heads , probably the 12407's (I see they're not available assembled in this small valve head)
Howards 110235-12 or 110315-10 with the Howards hyd roller lifters
New pushrods (around 7.144"? - will need the checking tool, hardened for use with guide plates)
New rockers - full roller rocker not important, maybe roller tip, stamped steel also okay with me
New valve covers and gaskets
New intake manifold (Air Gap style not important prob stay with an Edel, want to keep the 1806 carb though)
New timing chain/gear set
New timing chain cover, gasket and crank seal(will keep current short water pump)
Cam button
Possibly different distributor gear (will ask Howards for recommendation)
Intake gaskets
Head gaskets (will consult with RHS)
New head and intake bolts

It would appear the above setup will bump up the SCR to around 9.3 or so depending on the head gasket used. I'll have to see if I can work up an estimate of DCR but I don't think there will be any big surprises. My aim is to lean towards the low side on SCR but with the pistons .024 in the hole I'll want to keep an eye on quench.

Lift specs on these cams do not look like a problem with these heads. If I decide on the small valve heads I'd like to hear a recommendation for valve sets, springs, shims, retainers, locks, seals, guide plates, studs etc for use with a retrofit roller cam.

Any other recommendations on other parts is appreciated.

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