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-   -   What will help this cheapo motor? (https://www.hotrodders.com/forum/what-will-help-cheapo-motor-149509.html)

BMM 12-09-2008 10:51 PM

What will help this cheapo motor?
 
Hey guys. I need to get a motor in my Cutlass ASAP. Apparently, it would not be a good idea to get my bottom end rebuilt and throw on old heads because the compression of the new assembly could blow the seals on the heads...is this true?

Anywho, GM's 290 Horse long block assembly:

290 HP at 5100 RPM
326 TQ at 3750
.450" Intake
.460" Exhaust
1.94" Intake valve
1.50" Exhaust valve
76 CC Heads.

Now, I know the heads are less than ideal, but its affordable, and has a warranty, so. What Im wondering about is is there a bolt on or change I can make for cheap (no, I cant afford Vortec heads because then I need a new intake manifold) that will actually add some power? I was thinking a came swap are roller rockers, but I dont know if with these lame heads the extra 3-400 dollars would be worth enough power to justify it. If not, Ill just throw what I have at it and drop it in.

Thanks guys!

techinspector1 12-09-2008 11:08 PM

Don't change the cam until you know it will work with the static compression ratio of the motor. If you install a cam with a lot of duration and the motor is low compression, you may have less cylinder pressure after the cam change. (slower motor).

jimfulco 12-10-2008 01:42 AM

Quote:

Originally Posted by BMM
Hey guys. I need to get a motor in my Cutlass ASAP. Apparently, it would not be a good idea to get my bottom end rebuilt and throw on old heads because the compression of the new assembly could blow the seals on the heads...is this true?

I think that's just an old wive's tale.

As far as the 290hp crate motor, that's a 224* @ .050" duration L-82 cam in an 8.5:1 standard Goodwrench crate motor. I can tell you from personal experience that it's not that good of a combination, being kinda soft at low rpm. The only advantage I've seen is that it will run on the cheapest gas you can find without a hint of detonation. IMHO, it's not worth the additional $350 price tag.

bondo 12-10-2008 06:25 AM

Quote:

Apparently, it would not be a good idea to get my bottom end rebuilt and throw on old heads because the compression of the new assembly could blow the seals on the heads...is this true?
Ayuh,... Sounds like a massive load of Bull to me....

The inverse is normally True...
Fresh Heads will Hammer marginal Rings...
But,...
None of the Seals in a set of Heads, Ever see Compression....

BMM 12-10-2008 09:03 PM

Wow, lots of advice. Thanks guys. So, the heads cant support the cam. Now, if was going to swap the heads anyway, would the 260HP long block be a better choice in which I could also swap out the cam to one better suited to the swapped heads?

Im running a 2300 Stall, and there will be 3.73s in the back. thanks guys.

ap72 12-11-2008 07:24 AM

Quote:

Originally Posted by F-BIRD'88
If you're not going to use the heads then just by a GM short block (GM 350/260hp minus the heads) and rebuild your own heads and get your own mild/moderate cam. If say you did up or bought done #416 heads as discribed, a cam Like a Comp 265DEH 211-221-.442-.465-112 or the Summit #1103 cam would work well with your 3.73's and mild converter.

You want to get the finished cr up around 9.5 or so.

You can peice together and complete new engine using the GM goodwrench short block, new SDPC vortec SD8060ARPM head kit, a thin head 1094 gasket a KITSD174 cam kit +oil pan and pump and valve covers for just a few dollars more than the 350-290 crate motor and less than the 350/330HO crate motor.
Shave the heads to 61cc (approx .045") install with a fel-1094 gasket you will have 9.8:1 and will make 375hp and over 400ft/lbs torque (If you build it to spec) The main components are:

12605117
KITSD174
12555884
360450
FEL1094
14079399
88960604
SD8060ARPM (mill heads to 61cc)
12495491
220-2100

Assemble it yourself
These are all SDPC numbers http://www.sdparts.com
if you want a hi performance motor, don't buy a motor that is not and then discard half the parts.

Going with a used complete Vortec engine and rebuilding it the way you want is another viable option, that will costa bout the same but leave you with a little better results... You can pick them up for anywhere between $100-$400. That with a rering kit, an LT1 hot cam kit, and speed pro flat tops is a very low cost engine that is an excellent street build. You can buy all of those parts super cheap off of ebay or places like Midwest motorsports, competition products, and other budget speedshops.




BMM 12-11-2008 11:43 PM

Thanks guys. F-Bird, I have to givwe a big shout out to you for being kind enough to supply me with specific p/n's. As you can tell, Im essentially guessing, and this is going to aid me big time.

Thanks fellas!


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