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I could use some advice. 2.7L I'm putting a 2.7L into a '87 924s to go around corners fast in amateur event's.
I have one now I just took out of the crate with a new stock bottom end and Lindsey rebuilt head, mild web cam, Ti springs. But it's not going to make what I want (I'd be happy with 250+ NA with ITB's) I want to know what is possible and if where I can look for info on building the bottom end with a 3.0 crank. I'd be happy if someone could at least point me to information, ie. posts, books, video...
Thank you,
Steve Hickey
Car is pretty clean with under 70,000. I bought it with 18,000 and the speedo went around 40,000.
Hi,
You'd need new pistons and rods to stick a 3.0 crank in there.
You'd need a very hot cam and a dry sump oiling system to get to the RPM range needed for that 250hp goal.
And of course you'd need a non-stock ECU system to control it all.
You can talk over all this with Lindsey racing but be prepared to open your checkbook quite wide...
I would think a fresh 2.7L engine with a better cam/tuning could get to 180-200 hp pretty well.
If you really wanted 250hp it'd be easier to scrap these plans and buy/drop in a 968 engine - that started with 236 HP and you can eek some more out of it with tuning.
There was a guy on here last year who spent retarded money on building a 2.7 with an 8v head (I don't mean that in a negative way, it's just more than I ever saw someone actually spend on the quest to make power from an 8v NA motor). I forget his eventual power figures... 200bhp or something? It wasn't anything like 250hp. He had basically everything thrown at it, across the board to make that power. Except a standalone, but it was tuned by a professional guy to the bleeding edge of the engine's capabilities.
The really hot 2.5 SP2 race motors make in the neighborhood of 150-160 HP at the wheels. The 2.7 engines have to run a 150lb weight penalty. If you figure 10 lbs per HP, then it's fair to guess that a 2.7 in race trim will make about 175 WHP.
Realistically after all those planned mods I'd be surprised if you get anything over 180hp, especially with just a mild cam and stock oil system and bottom end. If you are really keen on keeping the stock 8v look and getting over to 200hp you need to either start with a capacity advantage over 2.7 or use boost. Sleeve and stroke it to around 3.3 and throw more money at the head.
Realistically after all those planned mods I'd be surprised if you get anything over 180hp, especially with just a mild cam and stock oil system and bottom end. If you are really keen on keeping the stock 8v look and getting over to 200hp you need to either start with a capacity advantage over 2.7 or use boost. Sleeve and stroke it to around 3.3 and throw more money at the head.
Thank you. I Know I need a bigger bottom end, I thought I did want too
Nice
So I'm learning that I'll be somewhat disappointed in HP numbers. That's ok, this car/ motor is to get educated while having fun. I'd like to thank everyone for their comments and information.
When I bought the motor and had work done to it my mind wasn't on going fast. It was more for the wife and I to tour back roads but she passed away so now I'm back to thinking about Me
So the motor will just do what it'll do while I make the chassis as lite as possible and build next motor, that was always the plan anyway.
Sell it and get a 968 engine, you can get your figures out of the 968 motor as the head has flow numbers that absolutely destroy even ported 8v heads. 250hp+ in a 968 is a VEMS ECU and a good tune away, it will rev to 7k with no fuss. I have a stock 968 engine in my S2, i've had a 924S, a 944S, driven the S2 with its original motor and then this swap. It is by far the best motor of the lot, throw a set of cams at it if you want even more.
Your other option is to turbo what you have, which would easily get you to your power target. 92.5hp per liter in the 8v is not going to happen without boost.
There was a guy on here last year who spent retarded money on building a 2.7 with an 8v head (I don't mean that in a negative way, it's just more than I ever saw someone actually spend on the quest to make power from an 8v NA motor). I forget his eventual power figures... 200bhp or something? It wasn't anything like 250hp. He had basically everything thrown at it, across the board to make that power. Except a standalone, but it was tuned by a professional guy to the bleeding edge of the engine's capabilities.
There wasn't an obscene amount of money thrown at the engine, Bought a 3.0 Block off Lindsey Racing, and a 2.5 Crank which they Knife Edged, I supplied them a 2.5 Cylinder Head which they ported to Stage 2, also 2nd hand 968 rods and new Wossner Pistons, making a 2707cc capacity, Web 274 Camshaft and best of all on stock 2.5L ECU Ignition and fueling including the Brilliant AFM ! I wouldn't call that throwing everything at it?
205 bhp / 205 ft lbs is not to be sniffed at ! especially in a 2300lb weight car.It's now done 5500 miles since it was finished (August 2016) and is going stronger than ever...
It's certainly not been tuned to the bleeding edge! it's incredibly reliable, drivable and economical etc..
I could go Twin cam head and TB's and most probably achieve 250bhp.
We tuned euro 924 S (160 hp from factory) with VEMS PnP kit (otherwise all stock, unopened engine) in order to get German TÜV approval (which it got) and result was 127 rwkw. That is 172 rwhp. Engine was not knock limited also, it would take many degrees of advance to get knock at all and by that time power was down (meaning ignition was way past MBT).
What we gained however in addition to power was much much improved response and driveability.
We tuned euro 924 S (160 hp from factory) with VEMS PnP kit (otherwise all stock, unopened engine) in order to get German TÜV approval (which it got) and result was 127 rwkw. That is 172 rwhp. Engine was not knock limited also, it would take many degrees of advance to get knock at all and by that time power was down (meaning ignition was way past MBT).
What we gained however in addition to power was much much improved response and driveability.
What was rwhp before VEMs. You guys drive me crazy comparing brake HP to rwhp... :-)
09-07-2017, 06:34 PM
'89 2.7L N/A questions
