JohnFromVentura

I would like to have my correct 67/300HP engine rebuilt.
I plan to have hardened seats installed for the exhaust valves but retain the the 300HP smaller valves. I plan to add the 350HP L79 cam.
I have talked to a local rebuilder that has a good name and can handle the job.
His take is:
Use Seal Power pistons with a master kit that has Clevite, Melling etc.
The bore is still 4.000 and he would use +.030 pistons.
Head Labor: $330
Machine labor: $350
Assy labor: $350
Master Kit: $350+$40 for L79 cam
Adders:
Polish all journals $48
Resize rods: $68
This is going to be used in my never abused 67 so I'm not interested in the HP thing ... just want a sweet sounding nice running engine.
What total piston clearance should be used with the cast alum pistons?
Do I really need the polished crank journals and resized rods?
the cost isn't the driving force in this thing but is it in the Ball park?
Thanks for any help!
John

Bluestripe67

I think you have a good plan. Have you actually seen his shop and all the equipment that he will use. This is important, as it will tell you about his organization to do work. Does he warranty his work in writing? I would add few thoughts based on personal experience. Get all the details in writing! When he bores it, make sure he uses a deck plate. Chamfer the crank oil holes, polish the journals, resize the rods. You can at the very least use a factory spec oil pump or a high volume, but not a high pressure one. Use a steel coupler on the oil pump drive shaft. Tack weld the oil pickup to the pump. New rod bolts are cheap insurance on the lower end. Your machinist will know the correct clearence on the pistons. If you want to help the breathing on the motor you yourself can port match the intake manifold to the head and do the same on the exhaust. Use the gaskets as a guide. An electric die grinder will work perfectly. Others here on the CF will add to this from experience. Dennis

midyearvette

hi.sounds like good prices to me, and if the shop is reputable, the build will be second nature with no problems. i would suggest all new stainless steel valves along with the seats and bronze wall guides, these guides and valves last a lot longer on un leaded fuel, actually leaded fuel of the past helped lubricate the cast in valve guides, also throw the old valve springs away, and don't forget to check the assembled height and shim as needed. i would also swap out the rockers for a new set, preferably comp cams with the roller tip , they are very easy on the valve train. as far as piston clearance, just follow the manufacturers guide lines here, cast pistons can fit tighter than forged because the latter expands more. good luck!!

midyear1

In addition to the above, assuming that the cylinder walls are in good shape, why not use +.020" pistons to leave the cylinder walls as thick as possible? It seems that most rebuilders automatically want to bore a standard bore block to +.030" because that's the size they have in stock.

http://www.jegs.com/i/Sealed+Power/8...56F20/10002/-1

http://www.northernautoparts.com/Pro...tModelId=15113

Virtually every piston is available in +.020 sizes.

Here are some numbers for your 327 motor in Summit search. I got you the numbers above for a 350 3.48" throw by habit.


http://store.summitracing.com/egnsea...=KeywordSearch

DZAUTO

John,
DO NOT, DO NOT, DO NOT HAVE HARD EX SEATS INSTALLED!!!!!!!!!!!!!!!!
There now seems to be enough experience with early heads that DO NOT have hard seats, and the BIG majority have NOT shown abnormal/excessive wear of the seat. The best solution SEEMS to be to have a good rebuild done and install STAINLESS STEEL valves. If you original 300hp heads, then they will have (or did when new) 1/94/1.5 valves and it is toooooooooooooooo easy for any competant machine shop to open them to 2.02/1.6 valves. When cutting the exhaust seats for hardened seat inserts, there is a genuine risk of cutting deep enough to go into the water jacket. When that happens, the heads are junk. DON'T DO IT!!!!!!!!!!!!!!!!!!!!!!!! If the original seats should show enough wear to be of concern, simply have them opened up to accept the 1.6 ex valves.

Scott Marzahl

Cast iron work hardens very fast, and GM testing has shown that for normal use hardened seats are not needed.

jim lockwood

Tom and Scott are giving you good advice about the valve seats. Don't do it! You run a tremendous risk of turning a perfectly good set of heads into door stops if you let the shop go ahead with this procedure.

Jim

midyearvette

sounds like good advice on the seats, these guys seem to have been there before, i would still go with the guides and stainless valves

Brian VH McHale

When I had my 67 327/300 re-built, I removed the 350 cam and replaced it with a stock cam. The 300 hp cam has more low end torque than the 30 cam.

MikeM

If you'll learn which way to move that chrome stub that sticks up out of the console, you'll find that the 350 cam has more than enough torque to do most anything. There's more positions there than N and R. Ask Al. He can show you how to use it.

Scott Marzahl

The smooth idling '929' cam will no doubt produce more torque than the '151' cam installed straight up in a low compression build because of the cam's valve timing. The "151" bleeds off a lot of dynamic compression, hence it works best within the 10:1+ compression range it was designed for. Speed Pro piston p/n L-2166 is the equivalent of the OEM L-79 piston and they would provide a SCR of approximately 10:1 (depending upon head gasket selection and chamber volume), and it will run fine on pump premium.

If you use the Speed Pro H660CP hypereutechtic pistons with a -5cc volume, and a thinner .026" head gasket you will be right about 9.5:1 SCR assuming your heads are 64ccs. Then do as the late 'Rev' Dale Pearlman liked to recommend and "install that '151' advanced 4 degrees for stump pulling torque." I'm using the '151' advanced 4 degrees in a mild 10.25:1 350 build and it pulls like a train to 5,500 RPMs.

Geek's 65

John,

Who are using for a machine shop?

Gary from Camarillo

Brian VH McHale

Al's the one that gave me the torque info. I do OK with that chrome stub now that my hand has healed.

65tripleblack

Use the .020 over pistons, do NOT overbore to .030 unless the bores are so badly scored that you have no chioce, which is doubtful.
Spend the extry 100 bucks or so, and have the machinist hone with a torque plate.
If you don't care about the "horsepower thing" then why not use a blueprinted version of the original 929 cam. One immediate benefit of this, is that because it develops less peak power than the "151" cam, it enables you to SAFELY use cast pistons. Modern, hypereutectic cast pistons are light years better than the old fashioned cast buckets. They will also enable the machinist to use closer skirt clearances (appx .0015, rather than .0030 for forged buckets), for quieter running AND better oil control, AND better sealing with less slap.
If I were building up the engine for myself, and insisted on a hydraulic,then I would employ the "151" cam, which is a terrific "all-around" cam..........making good low/midrange and excellent horsepower up to about 5500 RPM. It DOES NOT, however, have as much torque below 3000 RPM as the 929 cam.
I would NOT use the Sealed Power L2166NF piston in a high revving smallblock that I were building for myself, because they WEIGH A TON!!!! They are more than adequate, though, for the hydraulic 151 application. There are MUCH better forged pistons available from Ross or Wiseco, which are a good 50 gm lighter, for an additional 100 bucks, or so.
If your machinist has an ultrasonic tester, it might be a good idea to have him check your cylinder wall thickness, if he agrees to do it for a "nominal" fee, say, 50 bucks or less. It should take him no more than 10 minutes to check all 8 bores in 4 places around each circumference for a total of 32 readings. Recommended finished wall thicknesses for a mild engine should be no less than about .120 on the wrist pin sides and .160 on the thrust sides, with .200 being excellent for a full race engine!

65tripleblack

Scott,

The "151" is ground on 110/114/118 centers, which is 114 LSA, 110 intake lobe center. This means that if you line up the index marks on the sprockets, it will be "4 degrees advanced", and is how they were installed at the factory, also.
If you install the cam "straight-up", or @ 114 (114/114) then the cam would require more SCR, produce more peak power, but less torque.
What the Reverend was describing, was how the "151" was and is normally installed.

65tripleblack

I see no entry above for "balance rotating assembly". That should be done, especially since you will be changing over to a different design piston!
Without tipping your hand, ask him what "engine assembly" entails.

The absolute best way to improve torque across the entire rev range, WITH NO GIVEBACKS, is to invest in a high quality multi angle valve job, closely followed by a mild head porting job, mainly confined to the bowl area.
Different camshafts just move torque from one place to another, and shift the power band. The best ways to improve power are to decrease pumping and friction losses.

Tintin

I just went through this procedure with my car. I had planned to heave the original engine into a dumpster and go to an LS3 but my mechanic convinced me otherwise (he maintains a bunch of car collections around town and is a bit of a stickler on originality . I know I will regret keeping this ancient pos engine but I can always get rid of it later.

I think the pricing that you were given is pretty good, mine was similar. I had the hardened seats put in, if the shop knows what they are doing and have experience with these things, it is not as difficult as has been said. I went to 30 over because - why not? I also got new pistons, had the crank polished , new cam and main bearings and I got a cam and flat tappet lifters as a kit from Crane. I was fortunate to meet "The Cam Guy" from Crane at SEMA and he directed me to the appropriate cam that is a couple of steps up from the stock one. I had my heads cleaned up ,all new valves, springs, roller tip rockers, new pushrods, new timing chain and a better intake than the original 300hp one. I bought a lightweight flywheel and new clutch assy as well because once it is apart you may as well. I had the whole gizmo balanced as well, not just the rotating assy but the pistons, rods and all the other moving pieces.

The shocking part to all of this is that the engine was pulled from the car on Saturday and taken to the machine shop on Monday. It was done on Tuesday . Business is not good.. I paid less than $500 on the heads, valves included and about $500 for the block work. Something like $1200 in parts. The whole thing will be about $3500- which is basically nothing compared to a new carb'd LS3.

The most important thing going forward is to use only Diesel oil as there is no Zinc in standard oil any more because every car has a roller cam these days and to break this engine in carefully so it will last a while.

Good luck with yours, I will have only about 10 days of downtime in total and I will be on the road again

It is kind of odd in that every time I do something to the car I end up with parts left over I guess I will see if I can sell some of them as I don't have any reason to keep them all. I will take some photos , I have a carb, intake, snorkel air cleaner, radio shield and a lot more stuff that I do not want to have.

ghostrider20

Leave the valve seats alone. No need to install hard seats.

Why are you going .030 over on an engine with a 4.00 bore. You most likely need to bore, but why so much? Is the machine guy just too lazy to re-program the C&C machine? Pistons are available in .010 size increments. Never know, you may have to do it again sometime if something does not work out.

BADBIRDCAGE

Here is my take.

You are going to have the cylinder heads rebuilt completely, you are going to bore the block oversize (I would go .030 if the block will clean there), you are going to resize the bottom ends of the connecting rods and replace the rod bolts (as you should) and you are going to polish the crankshaft, removing material and increasing clearance, instead of having it ground to first undersize. What's up with that?

The prices you quoted sound quite reasonable to me. Check with your machine shop and see how much more it would be to grind the crankshaft. You won't regret it.

As far as rocker arms being replaced go with full roller rockers or stay with stock. If the fulcrum area of the rocker arm isn't being maintained stationary on the stud with the needle bearings then the rocker tip won't be maintained in its position and you aren't really gaining the benefit from the roller tip.

If you are going to rebuild the engine do it all the way. Don't stop above the crankshaft centerline.

Rich

Scott Marzahl

Joe, not to get too far off topic, but installing a cam advanced 4 degrees using a timing set with advance and retarded crank keyways in addition to the 4 degrees already ground into the cam is what Dale had found to really work well with the "151" IF you wanted more bottom end. It is the same way we installed my son's cam in his 350 to help get the 3.08 rear end moving. Duke ran the EA numbers and you loose a little off the top RPM range but gain it on the bottom.

Maybe we have a different understanding of what installing a cam 'straight up' means vs advance and retarded. I was taught that 'straight up' regardless of how much advance is ground into the cam, is simply installing the crank timing gear in the neutral position and aligning the timing index marks. With the #1 piston at TDC, the dots or index marks are both at 12 o'clock or straight up. Advance the cam by using the advance keyway, and retard the cam by using the retarded keyway, degree it and adjust as needed.

As for turning a SHP crank undersize, only do it if micro polishing will not clean it up. No need to take off that expensive Tuftrided surface that these SHP cranks were treated to which only runs about .010" deep. If you polish it, you may need to use the .001" undersize bearings to get your clearances.