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601 heads on a 74 l82 vette engine compression

  
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601 heads on a 74 l82 vette engine compression

 
DaveMann DaveMann
New User | Posts: 4 | Joined: 01/13
Posted: 01/09/13
03:48 PM

I have a basically stock l82 engine with 882 heads i want to put 601 heads on it but im concerned the compression will be to high for pump gas what would the compression ratio bump to if i just use a plain jane gasket kit from felpro? also would like to know what you guys think also i am not made of money dont want vortec heads or buying aluminum just looking for backyard ponys to zip around town stop light to stop light, also its mated to a 2 speed power glide 2500 stall 3.73 rear gears what cam should i switch to if i do the swap.  

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 01/09/13
04:20 PM

that might be pushing it, going from 76cc heads to 58cc?      are the 601s stock?    if so, they have smaller valves.

casting number info below.
http://outintheshop.com/faq/casting/heads.html

  your motor is the 9:1 version, correct?  

pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/09/13
04:32 PM

The 601 heads will choke the 350. You will never get any HP from a choked off 350.  If your concern is MPGs keep the 882 and look for an O/D trans. I.E. 2004R 700 R4.

You can get a thicker head gasket from Fel Pro or Cometic if you use the 601.

The 602 heads have small valves. 1.84"/1.5". You can put a big cam in it but whats the gain?

My advice keep the 882, and look for the OD trans. The OD trans will give you gas mileage and stand up to 350HP.

You can always get ride of the P/G and torque convertor. Then purchase an OD trans.

Bob  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 01/09/13
04:50 PM

+1

Any gain in compression will be offset by lower airflow through smaller valves. IMO, you'd be better of to find a different set of heads with a smaller chamber (64cc+/-) and bigger valves, then use head gasket thickness to get the CR where you want it.  
68scott385 68scott385 68scott385

BuzzLOL BuzzLOL
Enthusiast | Posts: 380 | Joined: 12/10
Posted: 01/09/13
08:52 PM

.. Bob/Pepsi is on the right track... the L82 is a hot engine... with a big hot 224/224 cam... what is frustrating you is the 2 speed PowerGlide tranny... basically, it takes off in what feels like '2nd gear'... switching to a 200-4R tranny from a Monte CarloSS, Buick GN(X), or Olds 442 (standard ones shift at too low 4000 RPM WOT) would totally transform the performance of your 'Vette... it has a deep digout 1st gear, better spaced 'real' 2nd gear, a 3rd gear to finish the 1/4 mile in... and an overdrive 4th gear that can lockup the torque converter for high MPG/low noise/low vibration/low engine wear cruising ... I think it's also the same length as the PowerGlide... add headers and freeflowing dual exhaust and you would swear it's not even the same car..!!  

pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/09/13
10:25 PM

Thanks Buzz glad you brought that up.

2004R is 27,750" overall length

700R4 is 30.750" overall length

700R4 is 30.000" Long only Corvette.

4L80E is 31.500" overall length

4L60E is 30.750" overall length

Power Glide 26.370" overall length

Bob  

pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 01/09/13
10:30 PM

trans G/R  1st  2nd  3rd  OD
2004R  2.74 1.57 1.00 .067

700R4  3.06 1.62 1.oo .070

4L60E  3.06 1.62 1.00 .070

4L80E  2.48 1.48 1.00 .075

G/R gear ratios...

Bob  

DaveMann DaveMann
New User | Posts: 4 | Joined: 01/13
Posted: 01/11/13
12:21 PM

I do have a 700r4 laying around. should i swap it in? And I believe its the 9.1 ratio. Also how much would a steel shim gasket bump compression? I was trying to think of a way to cut down combustion chamber space and I was thinking would brazzing the space smaller work? Any one ever done it or know of any one who has?  

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 01/11/13
01:22 PM

ive added tig weld to aluminum heads on dirtbikes and go-carts.   it definetly bumped up the power some.     i wouldnt bother brazing the cast iron chambers.   probably crack or warp bad.   the best thing to do is change pistons or heads.    just changing head gaskets isnt gonna yield much gain for the effort.     you should be able to find some 64cc cast iron heads fairly cheap somewhere,...machine shop, junkyard, craiglist, etc.
    id keep saving and look for a deal.

   the 700r4 is a great idea!  

68scott385 68scott385
Guru | Posts: 1990 | Joined: 10/09
Posted: 01/11/13
06:13 PM

On a good day you'd get 1/2 point boost in CR IF you have an 0.041 head gasket now and change to an 0.015 shim gasket. It is a lot of work for such little gain. The o/d trans is a good start in boosting acceleration and mpg.  
68scott385 68scott385 68scott385

DaveMann DaveMann
New User | Posts: 4 | Joined: 01/13
Posted: 01/11/13
07:00 PM

Well I just got done using the compression ratio calculator on the summit website, and it came up with 9.1, would you guys just port and polish these heads maybe gasket match? I put the thinner gasket into the equation and it gave me half a point, also it has after market flat tops with 4 reliefs cut in it. I have two sets of 882 heads i could use one as a test subject and if all else fails scrap.  

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 01/11/13
07:05 PM

Icon QuoteDaveMann:
Well I just got done using the compression ratio calculator on the summit website, and it came up with 9.1, would you guys just port and polish these heads maybe gasket match? I put the thinner gasket into the equation and it gave me half a point, also it has after market flat tops with 4 reliefs cut in it. I have two sets of 882 heads i could use one as a test subject and if all else fails scrap.

I recently bolted together a 350 with with 601 heads.,. it was all he had from a cooked 305.
The engine pulled strong to almost 4000, then it runs out of wind.
It was mildly cammed, otherwise stock.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

Dave632 Dave632
Addict | Posts: 2219 | Joined: 07/08
Posted: 01/11/13
08:17 PM

I always had good luck with the Powerglide trans. In my opinion the 1.76 version  is the strongest of ANY stock transmission. It handled up to 800hp in stock form in my cars. Aftermarket ones now can take 2000.
You do need some stall to get one to perform. I ran nothing but them in my last few race cars with excellent results.
They were complete JW glides in the last couple, don't need a tranny shield with them. Had little trouble with them but had to change clutch's every 50 or so passes.  
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Pontiacman2 Pontiacman2
Moderator | Posts: 8956 | Joined: 09/08
Posted: 01/12/13
02:51 PM

Dsc03489res
I used a pair of ported 601 heads on a couple of builds and they are not that bad on the street.
They are better then those 882 and 624 heads.
most 601 heads I have measured have 53-56 cc chambers.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 01/12/13
05:31 PM

+1
882's are only good as door stops.,. the worst heads GM ever produced.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder