My Engine Rebuild
#1
My Engine Rebuild
It is an Oldsmobile 350. 7A Heads.
Definites:
Sealed Power Flat Top pistons.
Edelbrock Dual Plane Performer RPM intake manifold.
Will go with the Rochester Quadrajet.
Double timing chain.
Performance water pump and oil pump.
I believe I will go with the original rocker arms and valves, just clean the valves real good.
No head work, although maybe I will just sand down the exhaust side.
Headers.
Question:
The main question is what camshaft to use to optimize this for maximum horsepower and torque. I definitely want to go hydraulic roller, I think it is worth it. Is duration 262/268 with .505/.505 lift too much? This is what I'm referring to: http://www.compcams.com/Company/CC/c...csid=1182&sb=2
Any other recommendations or input is appreciated.
- Kyle
Definites:
Sealed Power Flat Top pistons.
Edelbrock Dual Plane Performer RPM intake manifold.
Will go with the Rochester Quadrajet.
Double timing chain.
Performance water pump and oil pump.
I believe I will go with the original rocker arms and valves, just clean the valves real good.
No head work, although maybe I will just sand down the exhaust side.
Headers.
Question:
The main question is what camshaft to use to optimize this for maximum horsepower and torque. I definitely want to go hydraulic roller, I think it is worth it. Is duration 262/268 with .505/.505 lift too much? This is what I'm referring to: http://www.compcams.com/Company/CC/c...csid=1182&sb=2
Any other recommendations or input is appreciated.
- Kyle
#2
I assume you have 1972 vintage 7A heads and not the 1980s 307 7A heads. Put your money into the heads if you want to make power. Large valves like a W-31, for example. Spending money on a cam is wasted unless the heads are also improved.
#5
Highly unlikely. I recently paid $1100 for a stock-ish valve job on a set of Olds heads, though that included installing hardened seats on the exhausts, new big valves, and machining for teflon seals.
The days of $400 valve jobs on a pair of V8 heads are long gone...
#6
With that cam I would say no more than 9.5 to 1 compression, you should get a few quotes on the engine rebuild. You can get a set of speed pro aluminum heads for 1300.00. I paid 300.00 for a head job including clearance for a small cam, .499 lift . An olds engine rebuild should only cost around 600.00 more than a SBC, mainly due to parts costs. Any good machine shop can rebuild any GM engine. If you want to daily that engine you will want 8.5 to 9 to 1 compression in reality. Drop the roller cam to save 1000.00, just prime and use the right fluids or have the machine shop run the engine in for you.
#7
With that cam I would say no more than 9.5 to 1 compression, you should get a few quotes on the engine rebuild. You can get a set of speed pro aluminum heads for 1300.00. I paid 300.00 for a head job including clearance for a small cam, .499 lift . An olds engine rebuild should only cost around 600.00 more than a SBC, mainly due to parts costs. Any good machine shop can rebuild any GM engine. If you want to daily that engine you will want 8.5 to 9 to 1 compression in reality. Drop the roller cam to save 1000.00, just prime and use the right fluids or have the machine shop run the engine in for you.
#8
And yes 1972 7A.
#9
http://oldsrocketparts.com/index.php...luminum-heads/
http://oldsrocketparts.com/index.php...-top-end-kits/
https://www.jegs.com/i/Speedmaster/7....2152/10002/-1
I always shop around like crazy. I said pro comp but I think they are now speedmaster, The oldsrocket heads are direct bolt on and only 69cc or 80cc, pretty sweet.
http://oldsrocketparts.com/index.php...-top-end-kits/
https://www.jegs.com/i/Speedmaster/7....2152/10002/-1
I always shop around like crazy. I said pro comp but I think they are now speedmaster, The oldsrocket heads are direct bolt on and only 69cc or 80cc, pretty sweet.
#10
http://oldsrocketparts.com/index.php...luminum-heads/
http://oldsrocketparts.com/index.php...-top-end-kits/
https://www.jegs.com/i/Speedmaster/7....2152/10002/-1
I always shop around like crazy. I said pro comp but I think they are now speedmaster, The oldsrocket heads are direct bolt on and only 69cc or 80cc, pretty sweet.
http://oldsrocketparts.com/index.php...-top-end-kits/
https://www.jegs.com/i/Speedmaster/7....2152/10002/-1
I always shop around like crazy. I said pro comp but I think they are now speedmaster, The oldsrocket heads are direct bolt on and only 69cc or 80cc, pretty sweet.
Roller cams are not really compatible with the stock type valvetrain, wouldn’t recommend it.
And if you’re unsure of what’s included for $800 price the shop gave you then ask, and get it in writing.
#11
The Procomp heads are around $1300 for a pair with quality parts and proper clearances from someone like Bernard Mondello. He will only take the chambers to the 70CC, it is what he told me, probably a personal preference. The W31 was a 10.5 to 1 Olds 350 with 2"/1.625" valves, stiff springs, 308/308 .474/.474 cam and a huge harmonic balancer. Add a special Qjet, ram air, special calibration auto or 4 speed with steep gears, made a potent car. It was under rated at 325 gross hp, actually put out 350 or 360 gross hp.
#12
The Procomp heads are around $1300 for a pair with quality parts and proper clearances from someone like Bernard Mondello. He will only take the chambers to the 70CC, it is what he told me, probably a personal preference. The W31 was a 10.5 to 1 Olds 350 with 2"/1.625" valves, stiff springs, 308/308 .474/.474 cam and a huge harmonic balancer. Add a special Qjet, ram air, special calibration auto or 4 speed with steep gears, made a potent car. It was under rated at 325 gross hp, actually put out 350 or 360 gross hp.
- Kyle
#13
A couple years ago at "Street Machine Nationals" in St. Paul, Minnesota, I saw what was supposed to be a 68 or 69 W-31 on the chassis dyno. It pulled 344 HP, and it wasn't a fresh motor because some "blue smoke" came from the exhaust pipes. NHRA originally factored them to 350 HP, back in the day.
The factory .308/.308, .474/474 cam was a good one. I think they used the same cam in 1966 to 1969 4-4-2 W-30's and 68-69 W-31's and 1968 H/O (without A/C).
Remind me later and I'll try to find an old magazine article about W-31's that you can print out and read. I believe that a blueprinted W-31 ran 12.20's 50 years ago.
Perhaps you can Google "Rich Powers W-31" to find it. I think all the info then will translate to today.
The factory .308/.308, .474/474 cam was a good one. I think they used the same cam in 1966 to 1969 4-4-2 W-30's and 68-69 W-31's and 1968 H/O (without A/C).
Remind me later and I'll try to find an old magazine article about W-31's that you can print out and read. I believe that a blueprinted W-31 ran 12.20's 50 years ago.
Perhaps you can Google "Rich Powers W-31" to find it. I think all the info then will translate to today.
#14
Not sure why he would only take them to 70cc. I've milled more than a few sets of Procomps to 60 and below.
#15
Huh. That's interesting, maybe I can ask the machine shop to machine it so I could use those valves. I assume hydraulic flat tappet. And looks to be that the harmonic balancer is just over 7 inches? Anyone know where I could buy one of those or the significance of that (what does it do performance wise)? Just a thought.
- Kyle
- Kyle
#16
I believe you Mark and that was when the chambers were measuring 84cc. Still should be plenty thick, maybe worrying about intake fitment? Just his comfort level, is what I got from the conversation.
#17
Well those heads look like a good deal, and they're aluminum. I saw them at the beginning of my rebuild while still just perusing parts. Would I be able to reuse the valves, rocker arms, and pushrods? And from a company with the name Bernard Mondello Racing, I'd assume they're already performance machined "enough". I'm still beginner so I don't understand the significance of what Mark was saying. But it seems that smaller volume would be more compression, but I'm already pushing it with daily compression?
Sorry for my ignorance.
- Kyle
Sorry for my ignorance.
- Kyle
#18
I would keep compression below 10:1 for sure, I had 9:8 to 1 with iron heads and went down to 9.3 :1 and still have the timing dialed back pretty far in the summer with premium fuel. 8.5 :1 - 9. 1 would be better for me. You first decide what compression you want and then go from there. You can run a little higher compression with a cam with more valve overlap, but the combo has to be just right.
I was new to engine building a year ago and if I had to do it again I would just mill mill heads to 64cc or lower, slap in some new cast pistons and put a mild RV cam with headers and 4bbl thats it, keep it simple and low cost. When you start looking at big cam, big heads lots of other parts are stressed, valve springs need more pressure, which means all the hardware needs beefed up, then the cam has more pressure and can wipe a lopes easier, more compression is more stress on the bottom end bearings etc. etc.
I was new to engine building a year ago and if I had to do it again I would just mill mill heads to 64cc or lower, slap in some new cast pistons and put a mild RV cam with headers and 4bbl thats it, keep it simple and low cost. When you start looking at big cam, big heads lots of other parts are stressed, valve springs need more pressure, which means all the hardware needs beefed up, then the cam has more pressure and can wipe a lopes easier, more compression is more stress on the bottom end bearings etc. etc.
#19
With either the Edelbrock or Procomp heads, you need aftermarket rocker arms, screw in 7/16" studs, guide plates, different length pushrods and a electric fuel pump along with a block off plate where the mechanical fuel pump sits. The electric fuel pump is needed because the edge of the head over hangs the block. You can use stock rocker arms and pushrods with your 7A heads, just keep lift around .500". Problem is the faster roller cam ramps require more spring pressure requiring similar parts installed in the 7A heads. You should also get a roller cam with more lift the.505". The cheapest solution, while still gaining some performance, is a flat tappet cam, have the machine shop install 2"/1.625" valves in your 7A heads and have the bowls opened up with a bowl hog cutter to take advantage of the bigger valve. Hand blending with a grinder improves flow more, if done right. Even the larger valves and the bowls cut bigger adds about 30 cfm, around 210 intake, Procomp heads flow 240 cfm but have larger ports as well and need the Performer RPM intake. The Procomp being aluminum and have a superior spark plug position should allow more compression without pinging. Of course you will run more cam with those heads anyway. I am also plan on a roller cam next time, I can have more lift, better vacuum, decent economy and more power.
Last edited by olds 307 and 403; July 9th, 2018 at 06:24 AM.
#20
With either the Edelbrock or Procomp heads, you need aftermarket rocker arms, screw in 7/16" studs, guide plates, different length pushrods and a electric fuel pump along with a block off plate where the mechanical fuel pump sits. The electric fuel pump is needed because the edge of the head over hangs the block. You can use stock rocker arms and pushrods with your 7A heads, just keep lift around .500". Problem is the faster roller cam ramps require more spring pressure requiring similar parts installed in the 7A heads. You should also get a roller cam with more lift the.505". The cheapest solution, while still gaining some performance, is a flat tappet cam, have the machine shop install 2"/1.625" valves in your 7A heads and have the bowls opened up with a bowl hog cutter to take advantage of the bigger valve. Hand blending with a grinder improves flow more, if done right. Even the larger valves and the bowls cut bigger adds about 30 cfm, around 210 intake, Procomp heads flow 240 cfm but have larger ports as well and need the Performer RPM intake. The Procomp being aluminum and have a superior spark plug position should allow more compression without pinging. Of course you will run more cam with those heads anyway. I am also plan on a roller cam next time, I can have more lift, better vacuum, decent economy and more power.
And the factory cam 308/308 .474/.474 is only 135 on Summit!! Although just read it will make my brakes not work too well? Anybody own or driven a W31 and can comment?
Last edited by 87Brougham; July 9th, 2018 at 07:15 AM.
#21
Just a zinc additive or oil with zinc in it, plus the break-in is more involved. Thats is no big deal. The break-in is the hard part, with higher spring pressures some recommend break in springs, running valves loose on break-in. I broke in 2 Lunati cams with next stage from stock springs with no problems, full new spring pressure was applied. I think if once you get more than that you need to take more pre-cautions.
#22
Just a zinc additive or oil with zinc in it, plus the break-in is more involved. Thats is no big deal. The break-in is the hard part, with higher spring pressures some recommend break in springs, running valves loose on break-in. I broke in 2 Lunati cams with next stage from stock springs with no problems, full new spring pressure was applied. I think if once you get more than that you need to take more pre-cautions.
Thank you, all of you guys have been really helpful.
#23
The W31 cam is pretty radical, power brakes will be marginal. Also with 10.5 to 1 compression and a big cam, 2500+ stall and 3.55+ gears will be necessary. There are modern flat tappet cams with more lift, better vacuum and similar performance, contact Cutlassefi. I still say a small dish piston is the way to go but it depends on what you want for manners and where you drive it.
#24
Just to be clear for small block engine use, we have done both our SpeedMaster and Edelbrock aluminum cylinder heads as small as 60-64 cc's...
Thank you in advance,
Bernard Mondello Racing Enterprises, Corona, California. 951-371-1432
Thank you in advance,
Bernard Mondello Racing Enterprises, Corona, California. 951-371-1432
#27
Ugh! My cam bearings cam in the mail today, and they came from the same factory as my timing chain. They were both put in a bag, and both of the boxes crushed and opened inside! Now the bearings are all scratched and gouged up!!
#29
Yeah it's just a hassle I don't know why they'd do something like that. All the other packages were packed perfectly. And It is just inconvenient because I don't think they have a phone number.
Well that was actually pretty easy. I don't have to return them and they already shipped new ones out.
Well that was actually pretty easy. I don't have to return them and they already shipped new ones out.
Last edited by 87Brougham; July 12th, 2018 at 01:59 PM.
#30
Update:
Comp Cams 268H 268/280 .485/.490
ARP rod bolts, main studs, and head bolts
Scouted around and found a better machine shop. He bored my block, put new cam bearings in, put my freeze plugs in, pressed the pistons on the rods, put the rings on. $455. Satisfied with his work called him up again. Quoted $500 to do a valve job and make it so I can use stiff springs. I am doing larger valves as Olds 307 And 403 suggested. Which leads to my question.
Question now:
Looking at Milodon Stainless Steel 2 inch and 1.7 inch (I figure 1.7 lets exhaust leave quicker than 1.63) valves. Pretty hefty price tag, around 135 for 8 valves. But Sealed Power has some for only 80 for 8 valves. Is the benefit from stainless steel worth it?
I am not talking about horsepower (but I would like to know that too), but more as the strength and durability of the motor itself. It is worth the money if it will make my engine breath better and run healthier.
Comp Cams 268H 268/280 .485/.490
ARP rod bolts, main studs, and head bolts
Scouted around and found a better machine shop. He bored my block, put new cam bearings in, put my freeze plugs in, pressed the pistons on the rods, put the rings on. $455. Satisfied with his work called him up again. Quoted $500 to do a valve job and make it so I can use stiff springs. I am doing larger valves as Olds 307 And 403 suggested. Which leads to my question.
Question now:
Looking at Milodon Stainless Steel 2 inch and 1.7 inch (I figure 1.7 lets exhaust leave quicker than 1.63) valves. Pretty hefty price tag, around 135 for 8 valves. But Sealed Power has some for only 80 for 8 valves. Is the benefit from stainless steel worth it?
I am not talking about horsepower (but I would like to know that too), but more as the strength and durability of the motor itself. It is worth the money if it will make my engine breath better and run healthier.
#32
Fwiw worth you don't need to get fancy with the heads. I ran a set of #6 heads with 2.07 in. 1.63 ex. with just bowl work . I went 13.3's with an old combo using a 280h comp cam. same heads powered my last 355 with 10 to 1 compression same as last combo but with more cam and a well set up over all combo it went 12.2's in the 1/4 mile . Just make sure the rest of the drive train will work well with the combo. rear end gear, tq. converter, a good exhaust .
#33
Fwiw worth you don't need to get fancy with the heads. I ran a set of #6 heads with 2.07 in. 1.63 ex. with just bowl work . I went 13.3's with an old combo using a 280h comp cam. same heads powered my last 355 with 10 to 1 compression same as last combo but with more cam and a well set up over all combo it went 12.2's in the 1/4 mile . Just make sure the rest of the drive train will work well with the combo. rear end gear, tq. converter, a good exhaust .
#36
Now I blindly ordered the new valves, but I just measured my old valves and got 1.875/1.625. Will the 1.875 vs 1.999 make that much of a difference? Or would it be worth it to return my new valves, they cost 160 for all of them.
#37
The sealed power flat top. I had already ordered them because I saw so many other people using them.
Now I blindly ordered the new valves, but I just measured my old valves and got 1.875/1.625. Will the 1.875 vs 1.999 make that much of a difference? Or would it be worth it to return my new valves, they cost 160 for all of them.
Now I blindly ordered the new valves, but I just measured my old valves and got 1.875/1.625. Will the 1.875 vs 1.999 make that much of a difference? Or would it be worth it to return my new valves, they cost 160 for all of them.
#38
yeah I won’t be driving it too much, can’t take my car to college. It won’t really be a daily driver.
Last edited by 87Brougham; March 16th, 2020 at 05:03 PM.
#39
That cam should work ok, I would go with new rocker arms and bridges at minimum. Of course I would also add a 2200 to 2500 stall converter or it will suck off the line. I currently have the stock 1600 stall converter with 2.78 rear gears and I only have a 214/214 cam. It will barely spin the tires. I could lay rubber for a 1/4 of a block with a 2300 stall in a 2004R, it is going back in.