Engine Rebuild is Coming Soon

[78 Chevyrado]

Its about that time, cams wearing out and oil psi is getting low, plus I suddenly have a lot more money coming in.      I have to buy tires for the car and wheels for the truck (2 weeks), and then everythings going into the engine!

I'm gonna stick with the stock 350 short-block, but add summit heads and a comp cams roller cam as well as an offy dual port intake manifold.  I been wondering about that intake, so I'm going to try it.  If it sucks I'll get a performer EPS.

I'll be getting my short-block rebuilt, and with the summit heads it'll make right around 9:1 comp ratio.

I'm getting Summit heads SUM-152123
http://www.summitracing.com/parts/SUM-152123/

New Distributor - I'll be buying a bunch of stuff from this guy if all goes well
http://cgi.ebay.com/ebaymotors/SBC-BBC-CHEVY-CLEAR-CAP-65K-HEI-DISTRIBUTOR-6500-CL-_W0QQcmdZViewItemQQhashZitem51923cab44QQitemZ350345800516QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Offenhauser Intake 6007DP

Engine Rebuild Kit (should give 8.9-9.0 comp ratio with the summit heads)  Actual part number may change depending on which exact bearings I end up needing, but these are the pistons i want.
http://www.summitracing.com/parts/FEM-MHP133-311/?rtype=10

Comp Cams Roller Camshaft Kit  for an XR264HR
http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=157&sb=2

Comp Cam Roller Tip Rocker Arms 1412-16
http://www.summitracing.com/parts/CCA-1412-16/?rtype=10

I'll be keeping the edelbrock 1406, since it only has like 10k miles on it

At some point soon it'll have electric fans.  

And once I get it all buttoned up, I'm getting 2.5 dual exhaust with cherry bomb vortex mufflers.  I'll get 2.5 since I have half of it already.  

Once the engines built, I'm having a 700r4 built and will adapt it into my chassis.  I'll be keeping the 3.73 rear gears.  

Thats all thats concrete at this time.  the engine will be painted something like coke can red, since my interior is red.

[78 Chevyrado]

Oops.  Wrong section.  Could one of the admins move this to the members projects section?  Thanks fellas!

[78 Chevyrado]

the cam bearings in the engine kit are babbit.  Is there any special kind of cam bearings I should get to go with a roller cam?   Type and/or brand would be appreciated.  

Also what are the best main/rod bearings.  The ones in the kit say tri-metal.  Should I get tri-metal cam bearings? 


No racing, but I fully intend to keep my foot in it as much as I please....   I'm not light footed till money's tight

[Captkaos]

Cam shouldn't take any different bearings, how old are they?  I would replace them with the same manufacturer bearings.

[bgctrading]

clevite is a good bearing brand.

[VileZambonie]

Why a dished piston? I'd runa flat top with those heads. Is your engine a roller block?

[frito-bandito]

Nothing but envy here 

[78 Chevyrado]

Cam shouldn't take any different bearings, how old are they?  I would replace them with the same manufacturer bearings.

The engine kit I want to get comes with tri-metal bearings for the rods/mains but the cam bearing in the kit are babbit.  I've seen tri-metal cam bearings.   If enough stuff in the kit isn't what I want, I'll buy it all separate so I don't have a bunch of left over stuff.

Why a dished piston? I'd runa flat top with those heads. Is your engine a roller block?

Those pistons aren't in stone until the machine shop says they'll work right.  Depends on how much they deck the block and what head gasket I use.   

I figured the dished piston to get around 8.9:1 or 9:1CR.  I don't want to have to run premium fuel in it.  Whats the highest CR I could run 87 or 89 octane in?  Obviously I want the highest CR I can get but not run 91 octane.

No, the engine isn't a roller block.  I'm getting the retrofit cam and lifter kit with the links between the lifters.

[SUX2BU99]

Vile is right, with that size of combustion chamber you will be fine with flat tops. That's what I have with my 72cc Dart heads and I can run 89 octane fuel if I wish. You can always bump the timing back a little too if you are having an issue with octane. Also, are you buying the Offy dual-port or do you already have it? Word is that is one of the absolute worst intake manifold designs ever for making power. Or one of the greatest for limiting power, depending on your point of view  lol   If you are curious to try it and don't mind buying a Performer afterwards then by all means try it out but I haven't seen one good thing said about it.

[78 Chevyrado]

Vile is right, with that size of combustion chamber you will be fine with flat tops. That's what I have with my 72cc Dart heads and I can run 89 octane fuel if I wish. You can always bump the timing back a little too if you are having an issue with octane. Also, are you buying the Offy dual-port or do you already have it? Word is that is one of the absolute worst intake manifold designs ever for making power. Or one of the greatest for limiting power, depending on your point of view  lol   If you are curious to try it and don't mind buying a Performer afterwards then by all means try it out but I haven't seen one good thing said about it.

Flat tops might make their way in there.   I won't know for sure until the machine shop says, but I'm all for it if its better for me.   

I don't have the offy yet, but both me and my dad want to see one.  Kind of a novelty...    I've heard a bunch of bad about em, but I also heard about 1/3 good things.  I'm gonna try it and see what happens, though I'll never know how it did until I try another manifold.  I don't know, I keep going back and forth because it does cost twice what an edelbrock eps does, so we'll know when I've bought and paid for something.

[78 Chevyrado]

I think I may go with these heads

RHS Cast Iron Vortec   The summit ad says they have ductile valve guides, but RHS's site says they're bronze.
http://www.summitracing.com/parts/RHS-12410-01/

It will get an edelbrock 2716 EPS vortec intake.

Still sticking with the XR264HR Roller Cam

I want my comp ration between 9:1 - 9.5:1  somewhere in there is fine.

The truck will have headers and 2.5 dual exhaust, and h or x pipe.  cherry bomb vortex mufflers.

Anybody have any bad things to say about the RHS heads?  I don't hear of them a lot, but I've only come across good things.

Anybody ever heard this cam?  Comp XR264HR Roller.

[eventhorizon66]

The 12407's have iron guides and 1.94/1.50 valves.  The 12410's have bronze guides and 2.02/1.60 valves.

These guys offer those head assemblies for $415 each.

The XE256 flat tappet cam has the same LCA and duration @ 0.050", so my guess is it will sound something like this:
http://www.youtube.com/watch?v=_l27PwABKLQ

[78 Chevyrado]

The 12407's have iron guides and 1.94/1.50 valves.  The 12410's have bronze guides and 2.02/1.60 valves.

These guys offer those head assemblies for $415 each.

The XE256 flat tappet cam has the same LCA and duration @ 0.050", so my guess is it will sound something like this:
http://www.youtube.com/watch?v=_l27PwABKLQ

Sweet links!   That truck sounded good, now im really itchin to get mine done....  ha and i haven't even taken it apart!

I noticed on that site you put up they have 2 versions of that head.  One for a flat tappet, and one for a roller cam.  Does this reference an OE roller block and self aligning rocker arms?  and if so I should use the flat tappet head since I'm getting a RETRO fit roller cam?   That's what I ASSume it all means.  plus the roller cam head costs a bit more, but otherwise all the specs are identical.


And I also notice those heads accept the old Pre-86 intake bolt pattern and they also accept vortec intakes.   Does it really matter which version I use?  because I can get a performer EPS in either version.   I kinda figure since they're vortec heads, might as well get the vortec intake.

[eventhorizon66]

Oh, I forgot.  You will likely need the 12410-02 heads with the heavier springs.  There is a chance that because your cam selection is so mild the lighter springs will work, but I doubt it.  Double-check with Comp as RHS is a sister company and thus they use Comp springs, so they should know.  The two different assemblies are simply for flat tappet versus hyd roller (rollers usually need significantly more spring pressure to keep the valves under control).  It has nothing to do with the block or lifters used.

Based on what I've read, DO NOT assume you can use an early intake.  Yes it will physically bolt on, but the ports will not be even close to matching and there is usually not enough material to grind the intake to a port match.  That bolt pattern was offered for racers using raised port single plane intakes, which can be made to match.  USE A VORTEC INTAKE.

[eventhorizon66]

WARNING - non-expert advice alert!  Just the ramblings of a madman.

Some more thoughts on the issue:  When I say I doubt that you can get by with 12410-01, what I mean is I doubt that is the recommended or preferred choice.  But actually if it were me, I might try it for the following reasons.

1) The cam you've chosen is mild.  If you go with 1.5:1 rockers and keep the rpm well under 5500 (peak hp will likely be around 5000), I bet the valves will stay under control.

2) Yes the springs are lighter in pressure, but they are also lighter in weight (single spring vs double spring).  Apples-to-apples a lighter weight spring is always better.  Of course, this isn't an apples-to-apples situation but that is still one point to the credit of the single springs.

3) Even the single springs are pretty stout.  124 lbs. on the seat with 308 lbs/in rate.  That's pretty good.  Factory GM roller cams have run with much less than that.  Of course they are even milder than your selected cam.

But one major strike against such a gamble is if you do float the valves, you will dramatically shorten the life of the springs, lifters, and cam.  Roller cams/lifters do not last long after valve float that was severe enough to leave even small surface imperfections on the lobes.