I just bougt a 350 cutlass engine 1971 with 5 heads .i searched on internet one say it has 180hp another one say 240 . Can somebody help me what it is
71 olds cutlass 350 2bbl engine .the heads are from 69 5 heads .

Regards .oktay

 

First, since the engine is no longer stock, factory ratings don't really apply anymore. Second, 1971 was the first year that factory HP ratings were changed from SAE gross to SAE net. The difference was in the test process, but it resulted in a noticeable drop in rated HP. For 1971, Olds listed both the old and new HP ratings. The page below is from the 1971 Salesman's SPECS booklet. Your 2bbl 350 is the L65 motor, which you can see was rated at 240 HP gross (the old method) and 160 HP net (single exhaust) or 175 HP net (dual exhaust).

 

So thnx for the fast reply . The heads are at the moment at the shop for restoration .what can i do more to get 300-350 hp out of it ,

Sorry for my bad english .im from holland
Regards oktay

 

Get rid of the big dish pistons and use the 6 cc dish forging like a 68-70 310 rated engine , a decent cam , headers and rpm intake of you want 350 plus. The stock 325 rated W31 with its hotter setup is more of a 350-360 hp engine actually but needs gears and octane

 

Forged pistons 5.8cc+ also okay? Do i have to bore maybe 1or 2 sizes bigger?
Can i use extreme energy camshaft?
Headers?
Edelbrock rpm intake .
And should i use original valves ?

 

Bore the least required , that's up to your machinist to check your block first. If its still standard hope for 030 over but 040 or 060 is ok.

XE cams I would not use one, they are too aggressive of ramping and hard on valve-train harmonics , these have been known to have lifter issues at above 5000 rpm and nose over in some case, more seat pressure was a crutch to fight against it (lifter crash). These can make strong torque but may also ping on you if too small a grind and from the high cylinder pressure created.

If you want a Comp Cam the older Dual Energy series 275 DEH cam is something that would work well. I still want to try one later. It is made to help crutch the weak exhaust to intake flow ratio of a stock Olds engine. its like 219/233 at 050

Mark on here Cutlassefi is great resource and a dealer of Erson cams too and he has a TQ40 220/228 grind that would rock a nice 355 Olds with those #5 heads and the 5.8 cc pistons.

headers yes

RPM intake yes

original valves hell no
minimum of a bump up to 2.00/1.625 like a W31 but honestly why bother just go for the 2.07/1.71(1.68) SS valves on Ebay. They fit and just have the bowls blended in after they cut to the bigger seats. The Olds has a big enough bore to handle those valves.

Change to studs and guide plates too so you can adjust the valves like a normal engine too

minimum of Hughes BOP HD 2400-2600 12" converter

and at least a 3.08-3.42 gear , no 2.56 or 2.78 stuff.

Top it off with a Cliff Ruggles built Quadrajet or equivilent with a open element air cleaner , a 160-180 T stat depending on where and when you drive and your distributer gone thru with advance springs lighter to bring in total sooner.

 

Thnx for the info , great help .and very fast reply s .
I will search for these parts .

Regards from holland

 

your welcome , good luck. Main thing is above all things never use the "replacement " cast dish pistons from a regular auto re-builder. The compression ratio is way too low just as you would never ever use a re-builder provided "stock" Olds camshaft. They are super tiny 187/200 @ 050. This is why some give a stock 350 Olds a bad reputation for being slow and jump to a 455 or a LS swap. Car has no compression, no cam and often 2.56 gears

 

I have allready made a list on ebay, it will cost something but when i get 350 hp .i am happy with it .
Thanks again .

Whay do you think about nitrous ??

 

NOS is not my style but some love it. Takes a smart tune and setup to be reliable

 

The TQ40 would work well. Top it all off with a 750 carb and you'll make your 300-350 if you do as recommended.
Do you have a U.S. address to send to or direct to Holland? Let me know, thanks!!