[F-BIRD'88]

The 177 is capable of creating 650+ HP.

[bygddy]

I'm told its a comp 268, but honestly don't know, and if I'm going through the effort of pulling the motor then I'm going to swap anyways. I would port the 920's, and I'm guessing with a bit of "unshrouding" of the combustion chamber it will increase the cc's. As for the forged pistons, I really don't want to spend the money but if I'm going to be there anyways, I figured it just makes sense....believe me, I would rather do it cheaper....but meh....what do you do. The goal here is use the heads I have, valve springs and a set of long slot summit rockers, arp hardware throughout, the 750 I already have. And the blower. I assume the torque of the blower will help with my wussy 3000 stall and 456 gear selection lol...so if i order a rebuild kit without pistons, then order the ones you mentioned, are the moly rings that come in the rebuild kit going to work? I have to admit, I have driven in a couple blower cars, one with an 871 on a 496 and a few paxton pushed 5.0 stangs....and the low end off idle is so violent....i just always assumed the price to play in that territory was outrageous so I never even considered it. But really, If I can make 355 that will turn these huge meats I will be happy. And 114 is readily available just down the street from my shop so if a can do a pulley swap, a jet change, and go to the track every few weekends it would be perfect.

[bygddy]

I'm going to assume a modded hei isn't going to cut it in this application and will need an ignition box with boost referenced timing retard? Or is it something where I'm running say 7psi and set the timing at a locked "safe" amount and leave it alone?

[F-BIRD'88]

look for a MSD 5462 BTM box on ebay,Kijiji etc ( its there). Hooks to a HEI.
Its worth more to you than the forged pistons at this point.
If the cam is a XE268H-10, use it as is.
girlie cam blower cam and lifters summit K1105 $99.

If all this is just to much bother, build your 383.

[bygddy]

Originally Posted by F-BIRD'88

look for a MSD 5462 BTM box on ebay,Kijiji etc ( its there). Hooks to a HEI.
Its worth more to you than the forged pistons at this point.
If the cam is a XE268H-10, use it as is.
girlie cam blower cam and lifters summit K1105 $99.

If all this is just to much bother, build your 383.

Nope, not too much bother at all, I have to make rear shock mounts, as there currently isn't any at all, rebuild the trans, run exhaust, and pull the motor, realistically the dollars and cents isn't going to be alot different then a 383, but the power, the grin factor, the cool factor, and the fact that a pulley change, some good fuel, will hopefully get me into the 11's it seems dumb not to do it. I did an alum head big cam 350, did a budget 350 with junk parts, did a 406 this summer, all were successful, so this is something I badly want to try...and with a little help, (alot) and some common sense I think I can make it work.

[bygddy]

And your right, several of the MSD box's on eBay cheap cheap....

[F-BIRD'88]

Is the 177 blower going to fit under the hood on your car?
If not, is that a deal breaker?
Hood scoop, Blower scoop?
Got to question if it's really nessessary to rebuild this engine at all
in order to supercharge it. (moderate 5-7psi boost)

[bygddy]

Originally Posted by F-BIRD'88

Is the 177 blower going to fit under the hood on your car?
If not, is that a deal breaker?
Hood scoop, Blower scoop?
Got to question if it's really nessessary to rebuild this engine at all
in order to supercharge it. (moderate 5-7psi boost)

I could stuff an 871 under the hood with no issue.....lots of space and the motor sits looooow.......OK, so in theory sure, I could throw a blower on this as it sits, but I know the oil pressure is on the low side, not bad, but not great. No smoke, no noise, but the unknown factor concerns me....I could pull the heads, port them, freshen them up, and install with new valve springs, add a new HEI, the blower and the timing retard. And let it eat.....if I get the summer out of it then great.....but really, assuming a small cam, 268 or possibly even an RV style cam that's already in it, what kind of power can i make at 7psi?

[F-BIRD'88]

Once the heads are home ported, well in excess of 430hp. (I am being conservative)
Lots of torque for your mild 4.56 gears too.

Many of the engines we have done were either stock or had a simple "krylon rebuild"
(hone, rings, bearing, cam, lifters, timing chain and a paint job)

Normal supercharged combustion is not hard on the engne.

The stock heads will need tweeking to get power. At least the 920's are a good one as a start point. They turn out good
with generous porting.

The 177 on your motor is goingto make impressive power with just the default 1.71:1 drive ratio. (4-5psi)
at a 2:1 drive ratio (5 to 6.5psi) it will make great power and torque. ( more than the 383 you planed on)

at 2.33:1 it will make about 8-10psi. Big power but is time for some 110+ added to the 92 and more retard.
This well in excess of 460hp on this simple motor. ( more like 500 if you do the heads right and get the crane cam)
This is more than you will want for typical street crusing. The only place you will be able to use the power at 2.33:1 is at the track so might as well run straight 110+ and give it all the timing it deserves. 500++HP.

Beyond 2.33:1 the gains get smaller and the compressed air starts getting heated. (diminshing returns) Intercooling becomes a nessessity.
Alcohol fuel ( Ethanol or Methanol or water Methanol injection and race gas to cool the charge. 560+hp 15+psi.
This the extreme but still on those crappy heads. This is where you may see an engine failure. From a tuning mistake.
You are way beyond street use at this point.

600++hp with a head swap.

For street use you want to stay in the 1.94:1 to 2:1 blower drive ratio zone. Lots and lots of reliable power.
some retard- 94 octane or a blend of 94 and 110+ or water injection (allows more timing and power)

remember even at mild blower drive settings (5-6psi indicted boost) the HP does not discribe the big engine torque the supercharged engine makes. The key is to make use of the boost.
The crane cam allows max perf and 6500+++rpms.
A 224-234-114 (summit) HYD cam will make in excess of 450hp and 6000rpm. ( A hyd gets limited somewhere around 6200-6600rpm where a solid keeps reving strong) You really notice this when using high blower boost. The engine really wants to rev.

[hcompton]

Originally Posted by bygddy

I could stuff an 871 under the hood with no issue.....lots of space and the motor sits looooow.......OK, so in theory sure, I could throw a blower on this as it sits, but I know the oil pressure is on the low side, not bad, but not great. No smoke, no noise, but the unknown factor concerns me....I could pull the heads, port them, freshen them up, and install with new valve springs, add a new HEI, the blower and the timing retard. And let it eat.....if I get the summer out of it then great.....but really, assuming a small cam, 268 or possibly even an RV style cam that's already in it, what kind of power can i make at 7psi?

If your going to pull the heads replace the oil pump as well and the shaft with a arp one. The stud kit is also cheap and worth an update. I usally use meldon high volume pumps they put out a little more pressure and a lot more volume keeps the oil pressure steady at high rpms.

[bygddy]

Originally Posted by hcompton

If your going to pull the heads replace the oil pump as well and the shaft with a arp one. The stud kit is also cheap and worth an update. I usally use meldon high volume pumps they put out a little more pressure and a lot more volume keeps the oil pressure steady at high rpms.

See, and here's where I'm at.....I can swap heads in the car, blower, dist yada yada yada without having to pull the motor, I have pulled motors, and normally its not an issue, but on this its a huge pain....we have done my dads motor a couple times on hisn34 chev and it sucks, this is very similar...fenders off etc etc....anyways....it would be interesting to simply add blower, work the heads, and see how it works....

[F-BIRD'88]

There is no reason you cannot get many summers out of this motor.
You have to get real, real agressive on boost (blower drive ratio) (and tune it wrong) to get into trouble.
Most people settle on about a 2:1 drive ratio for this blower, on the street on 92 octane, 8.5:1 with some retard and enjoy years and years of trouble free supercharged power All on a stock short block.

like I said I'd rather see you spend the money to get the spark retard box than forged pistons, etc etc.
(reasonable, streetable boost)

[1Gary]

Originally Posted by F-BIRD'88

The 177 is capable of creating 650+ HP.

Is it 177 a Whipple??.

What is the peak of a 177 at what RPM??.

What is the CFM conversion to PSI??.

[F-BIRD'88]

I'm doing a 305 essentually the same. And will be pushing the envelope to explore the limit.
Big boost (good fuel) big rpm. max possible power. It's a free 305 thats in good shape.
If I do find the limit I don;t care. There are more 305's. LOL.

@5-7psi I will never hurt this stock short block. And you won't either.
I been doing this for 35+ years. Nitrous too.

[F-BIRD'88]

Originally Posted by 1Gary

Is the 177 a Whipple??.

What is the peak of a 177 at what RPM??.

What is the CFM conversion to PSI??.

No its not a wipple or a latham
its a roots blower. Compression is in the intake manifold, unlike a wipple screw blower.

there is no Peak. but at beyond about 2.4:1 drive ratio the air starts getting heated. needs intercooling (Alcohol) you are getting beyond the sweet spot (boost VS compression heat) You still make more power but the chance of detonation from heat is rising, requiring high octane fuel and or very low engine compression and spark retard. Or charge intercooling.

What is the CFM Conversion to PSI? Blowers don;t work that way.

Manifold gauge Boost is a back pressure reading. Its telling you what is not getting into the motor. Not how much power you are making.

A good breathing motor ( heads cam exhaust) or a large CID motor will show a lower boost reading at a specific drive ratio.
and make more power per psi boost.
A restrictive engine ( poor heads, small cam, poor exhaust) will show a higher boost reading and make less power.

Excess blower speed creates overheated air and higher (false) boost readings, but less density but less power and vastly increased chance of detonation . You are way beyond the designed sweet spot.

Boost does not kill engines.. Detonation kills engines.