cspataf

I just joined and have a 1976 Cutlass Supreme 350 with 47,000 miles. It is all original except for dual exhaust. I was thinking of installing the Edlebrock 7111 manifold and 7112 cam. Do you think I would see any performance improvement with the stock heads? Also, I just rebuilt my quadrajet, and was think of using it. I would appreciate any input.

oldcutlass

Welcome, now post some pic's!

You might notice a small increase in power with that cam and rpm manifold, but it will breath and sound better. The rochester will work well with most mild upgrades! The performer is a good all around manifold if your not going to push it up to 6500 rpm.

captjim

The car will run terrible with that cam and intake on a stock 76 350. The compression ratio is too low, not to mention that you probably have a 2.41 gear. Best bang-for-the-buck IMO is to get some older 350 heads, they will bump Cr up from 8 to 1 to around 8.7 to 1 +/- That will allow you to upgrade the cam to something in the 210 @ .050 range. Save your money and do the whole top end at once. IMO, the stock intake is fine, if you do change it, get a used Performer for $100.

captjim

This post makes no sense at all to me. A stock 350 is done below 5 grand, much less 6500. That cam is waaaaay too big for a stock 350. A Performer "up to 6500"??

coppercutlass

Fwiw. Im runing a dog stock 307 in my 72 cutlass at the moment my last 350 gave up. With a 650 holley dp and a spacer, headers x pipe w/ 3.73 gears and a 2200 stall It runs awesome for a 307. keep your 350 stock for now until you can do a proper rebuild. For now add some gears in the rear a converter that will work for now and with future mild mods add some headers and that will be a change you will feel. That little 307 will smoke the hides a little and will hold it's own against most imports.

Intragration

x2 on the gear and converter, primarily the gear. I'd say leave the motor alone for now, and definitely go with the Q-jet. You might also think about headers. They may not provide a huge power increase at this point, but they will help, and then you'll be set for future upgrades to heads, cam, etc.

oldcutlass

I said a performer if he was not going to go up to 6500 rpm! it's rated from idle to 5500.

cspataf

Thanks for the input. I think I will go ahead with the rear end gears and converter, since they need to be done anyway. I should enjoy that change for a while before tackling the engine.

coppercutlass

2200 to 2400 stall will work good with what you got and with future upgrades. Also bump the timing to about 10-12 depends on how the car runs . Curve the distributor. It should wake up a bit with that too. There is alot of little thing's you can do to make the car wake up engine wise with out going inside. Headers and an x pipe with a free flowing exhaust work too.

cspataf

Thanks again. Its nice to have a list of less drastic things to do that should make it much more fun to drive.

71supreme

You'll definitely notice the difference with new gears! When you get into the engine mods, don't toss those #8 heads, with a little work they can be every bit as good as the earlier models without the extra cost & effort of getting new heads:

http://www.members.shaw.ca/gregtsmith/Head_Porting.htm

Hope it helps. Good luck with your project!

coppercutlass

the 8"s can work but by the time you mill them to get some decet cc's to bump compression it aint worth it. You are better of running early heads to bump compression is you keep the stock pistons. Even if you get flat tops the early heads are just the way to go price wise. I ran a 73 350 with 72 7a heads to bump compression. The 73 and up 350's went to smaller cc dished pistons but bigger cc heads so putting earlier heads on a later block works out perfect. That combo went 13.86 in the quarter and was very mild great on the street and good enough to go fast enough to have fun at the track best of all drive train and engine combined i had less than 5k into all of it .

captjim

These kind of blanket statements make me disagree with you. Flat tops pistons and older 350 heads can yield Crs over 10 to 1. That is too high for a DD. However, flat tops and #8s yield 9 to 1, perfect for a mild street car.

coppercutlass

I ran 10 to 1 on The street with pump gas 93 no isssue. Now i ran 9 to 1 with a shim gasket and milling my heads with the stock 14cc dished pistons on the 73 350 7a head combo. There is alot of little details that yes i leaveout but those are also things that people look and when they build stuff. I ran my last 350 with flat tops .030 in the hole my heads milled .024 with a .040 gasket . Yeas you can achive 9 to 1 with stock 8's but if he is just looking to do a simple little cruiser occasional strip blast the early head later year shortblock will cost alot less than using the flat tops. Im sorry i just make statements to throw out there more or less suggestion my opinion you know. If you can quote where i said the 8's would not work then i owe you a six pack my friend. I just said the earlier heads are a better bang for the buck kind of statement you know. Sorry i just like to throw budget friendly suggestions out there.

captjim

Your post in this thread tells him not to do anything to the engine until he can afford a "proper rebuild" Now you say to pop the heads on a 35 year old engine.

A lot of guys don't want to run 93 octane, and they don't want a big cam. 93 isn't even available everywhere and toss in some altitude and you are detonating. Other advantages on the #8 head are hardened seats and larger exhaust valves.

coppercutlass

I was suggesting for future reffrence i never said for him to do it now i was just mentioning it since someone said to keep the 8's. I gave my opinion on it that was all take it with a grain of salt. You really need to think before you speak.

captjim

You are the one who needs to be more concise. You even stated,
"Im sorry i just make statements to throw out there more or less suggestion my opinion you know"

coppercutlass

i said that sarcasticly. Im just voicing my opinion. It's hard to be a smart @$$ with no emotions in typing. Just like you have your opinions on stuff it does NOT make it right becasue we all have diffrent thoughts the world does not revolve around you sir.

captjim

In no way do I think that, but when I see you making innacurrate statements or giving bad advice, I will call you on it, as I expect anyone else should do If I do the same. The original post was about a cam and intake ciombination, which I answered.

coppercutlass

i did not give false info. you can run the combo's i mentioned . I could atleast i have 93 at every gas station near me. The builder also has to do his home work when advice is given i do the same.

ihengineer76

The advantages stated here are only good for an untouched head, which no one would put on a rebuilt short block with flat top pistons. The #8 head only has induction hardened seats, which is little more that surface hardening. One valve job and it will be wiped out. This negates that advantage since you would be putting new hardened seat in either head now. The head also may have bigger exhaust valves, but it has more restrictive exhaust ports. You can make it flow better with some port work, but why not start with an earlier one which needs only a little clean up. As you stated earlier, the earlier heads yield too high of CR's but the older heads are rarely at the 64 cc's they are claimed to be. 67-68 is usually more in the ballpark, and the greater thickness of most modern head gaskets also lowers CR. If the O.P. is putting new pistons in, why would he not choose one to match a good head vs. going straight to flat tops being forced to run the large chamber heads? To really put it in perspective, how many people do you see trying to get more out of their engine looking to sink money in a pair of #8's? My guess is the pool will be pretty shallow.

cutlassefi

x2.

captjim

My point is that many guys consider the #8 heads worthless, but for someone looking for an easy way to make a mild 9 to 1 street engine, IMO the #8 heads/flat top pistons are a good option. Also, you say "choose a piston to match" but those options are limited. Flat, 3cc Probes, 6cc Speed pros (when available). Yes, you can cut a dish in the flats. It would be nice iif there was a decent cast piston with a 14cc dish and a 1.605 p/h available.

coppercutlass

yet egge machine makes good quality cast pistons, flat, 7cc, and 14cc.

captjim

Yes they do. For $400 you get cast pistons..................

coppercutlass

But they are a quality product. That is probably better than the run of the mill cast units. I dont get it on one hand you go on about buying and running good parts now you say 400 is too much for a great product. I know forged units from trw/ speed pro go for roughly 400 maybe a little less but it all come down to the goals you know. On one hand you might spend 30 more for the cast 14 cc units but you get new cast units that wont bump compression that high. You said there where no good unit's., egge makes a great product .

ihengineer76

The man offers you a plausible solution and you gripe about price. If you want cheaper cast pistons, get Sealed Power or KB for 25 a pop. Wait for it..."but they have too much dish". The reason that the Egge pistons are more and the KB and Sealed Power are less is strictly due to a manufacturing standpoint. The dish on the cheaper pistons is a standard OEM dish size. They use this portion of the mold over and over again with many different piston sizes. All they do is change the outer sleeve and bottom wrist pin boss molds for different diameters. When you get into less common dishes, the price goes up because of retooling, and small batch sizes. It is simply economy of scale. If you want specialty, you pay for it. Plain and simple.

captjim

I understand all that. But, my point is that if those cast pistons are $400 and Speed Pros are $400 forged, why not use the flat tops and #8s to get the same CR as the 14 cc dish and #5-#71a heads. Those older heads flow a little better, but the reality is all the older iron heads can benefit from a few hours of porting. For the same money you end up with a stronger piston, flat top (better flame travel), and better quench.

ihengineer76

In all reality, it pretty much a wash between the little extra porting time you would have to put in the 8's vs the money saved on head work, but spent on pistons with the older heads. The comment about quench does make me chuckle a little, because of the little quench area we have with any of the stock olds heads. The 8's will work fine for a mild build, but do have their limits in higher performance applications. It might make a decent turbo head, though...

captjim

I understand that the quench area IS small, but it is there. Also, All I have EVER said is that it has an application as a good 9 to 1 street engine. The chambers are too big to get decent compression and certainly the older heads are a better choice. So, if it is a wash, and you already have them (no $50-$100 for cores) and all else is equal AND you end up with forged vs cast, then IMHO the #8/flat top is a better choice. There are many different ways to skin a cat.

captjim

I don't know how you can say that when that engine had a bottom end/bearing failure.

coppercutlass

We came to the conlusion something came out of the bearing passage because of the way it was damaged it looked like it came out of the oil feed hole and out of the bearing. It was the bottom side of the bearing not the top side. And it was only that rod bearing. And the rear main bearing looked like it started to go. If it was detonation it would have failed fast I had 1968 w 31 cast flat tops on there those poor things would have shattered.

coppercutlass

Don't know what you are trying to prove. I specifically remember posting it was the bottom side of the bearing and not the top. Not all bearings failed 80 percent were in great shape still. You drill me about using crappy parts but yet again if it was detonation it would have failed very soon I had no room for error. I ran the same amount of timing from the day I broke it in till the day it died. I put enough miles and runs on it to rule out detonation.

captjim

I stated that IMO 10 to 1 was too high for a D/D on pump gas. You contradicted that with,
" I ran 10 to 1 with no issue"
Like many of your posts, this was not complete. You can't say "with no issue" when the engine failed due to a bearing issue. You can say that detonation was no the culpril, but the fact is you don't really know. If the engine was still running fine, then yeah, you could say "no issues".

Personally, I have never seen a n/a piston shatter. Not saying it hasn't happenned, but I have never seen it. In my experience, detonation problems manifest themselves in rod/bearing failures.

coppercutlass

Like I said I ran it long enough to know. And timing never moved. And it had no signs of detonation. If it was detonation it would have showed up on more than just one half of the rod bearing and it was the side that usually does not get damaged by detonation.

cutlassefi

Chances are it was either out of balance or a mismatch of some sort on the cap/rod.
How were the wrist pins? Ring lands?

coppercutlass

Lack of balance is probably more like it. Ring lands where good and the pins moved the same as the day they got pressed on. I also for got I cracked piston skirts on 5 pistons.

cutlassefi

Do you see my point dude? I'm trying to help, but as usual you only gave part of the info! Christ you're like a politician!

Take a fricken minute and put it all down, once. It'll save you a whole bunch of grief in the future. I'm done trying to help you, you keep digging your own grave deeper and deeper.

coppercutlass

How . I put on there what I needed to. If jim was using info from another post I explained in detail all the parts that got messed up so I should not have to explain. I appreciate you helping me.

captjim

ufb