Has anyone here done this? What kind of results have, or might, you get?

I am looking into alternatives for my 5-speed car. I'll chunk the 305. Would want a high, quick reving small block...possibly making strong hp numbers in the 6-7000 range. Would hope I could manage good enough torque for good normal driving purposes as well. I would expect to use a mini-ram or some LPE/ACCEL aftermarket induction, and AFR heads to help the breathing necessities. Don't know about cam, pistons, compression, etc...or even where to get the crank.

Ludicrous?

Would getting a 400 and destroking it to a 377 accomplish the same objectives easier, and at a more reasonable price?

BTW...tore apart an engine for the 1st time today...a 305 out of a 75 Camaro (I think).
Just for practice. Any suggestions for what to do with any of these parts?
The motor had been sitting up for several years. Running at time of removal...Has some sort of recessed shape type pistons. I guess it must be a low compression piston...


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89 TransAmGTA L98/Auto Grey/Grey T-Tops
Best 1/8th: 9.02 @ 76
89 TransAmGTA LB9/5speed FlameRed/GreyLeather Hard Top

 

I was debating this a few months back stroke or destroke. If you were to destroke a 350 with a (large journal) 327 crank it would spin into the area of 7k fairly easy but you would need to reinforce the bottem end. The stock rods wont hang at 7k. This isnt a very streetable option seeing how a street driven car doesent see much higher than 3k on a normal basis.
A 377 would be more streetable seeing how the avrage 377 makes power more in streetable area with room to hit 7k. I was told by (the good) machine shop and carnk service place that unless you purchase a crank made for stroking a 350 or destroking a 400 its going to be a toy engine. This means that the pistons are not at a natural angle and I would be lucky to see 50k miles out of the engine before the block is toast. I personally ended up getting a new 350 crank.

As far as that 305 goes. Did you mark the end caps on the rods or the main caps? If you dident you will have to get the crank turned and get the rods matched to the crank. If you dont and put the engine back togather it will eat bearings like a cop eats jelly doughnuts.
SSC

 

BTW, you do realize that if you use a 327 crank in a 350 block, that hasn't been bored out, then you will get a 327?


AJ

 

destroking isn't a real bad idea with a stick since less torque at the low end helps get the tires to hook up. you'd have more power with the 350, but the 327 would be fun. either one will rev that high. the 377 isn't a great idea since the 400 blocks are getting harder to find and if you used a newer block you could still use the same flywheel. to do this just find a one piece rear main seal 350 block and order a crank for it from someone like eagle or lunati. otherwise if you go two piece rear main your going to look for a 350 block and find a 307 (chevy not olds) crankshaft as they are easier to find than the 327 large journal crank. you could just build a 302 if your going to destroke so you could keep your cubic inch close and still tell people you race it's a 5.0L. that just takes a 350 block with an L99 crankshaft and rods which are available through most gm parts dealer for the rods and the crank can be had from a gm dealer, autozone, etc.

 

use your 305 rods in your new block, they are built stronger than the 350 rods, they are the same size and journal as 350, but just a little stronger

make sure u use large journal rods though
and main caps have a number on them in accordance to position on the block, so does the block

[This message has been edited by nagga (edited December 09, 2001).]

 

I'm in the process of saving up for a 400 to destroke to 377 then put tt's on it. I'm pretty excited about it! I cant decide on a miniram || or whether to get a carb converted to EFI. I'm going to pop a t-56 in there and it's going to be a blast

 

There isn't that much difference in the RPM capabilities of the 2 engines. Certainly not enough to offset the loss of the cubic inches.

The 377 is a little different matter though; you go from external balance to internal balance, and 5.565" rods to 5.7" rods, as well as losing the 31 cubic inches. Still, if I wanted to make a motor that would produce as much power as possible, I'd be looking for ways to add cubic inches whenever I could, not throw them away.

I've never done that to a 350. However, when the 350 became available, I recall quite a number of people going the other way, taking their 327s out and putting 350s in. I can't recall a single person who ever wanted to go back after doing that. I wonder why.

Something to think about.

Keep the oil pan bolts, timing cover bolts, timing cover, oil pan, the oil filter adapter, and stuff like that. Also the crank is the same casting as a cast 350 one, it will be a 442, maybe balanced slightly differently but maybe not even that. Ditch the rest.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

Destroking to a 377 works well in a light car with deep gearing and manual transmission.All else being equal you will never catch a higher geared 383 in a 3600 lb car in the 1/4 mile

 

I will probably stroke the L98 to a 383 when the time comes...but my goal for the 5-speed would be to have a high horsepower motor at high rpms (greater than 6500, hopefully something in the 7000-7500 range)...would think a destroked engine (350 to a 327 the easier to obtain) could do this. Can you accomplish this just as easy with a 350? It seems going to a 383 would defeat the goal I am trying to reach. I also like the idea someone mentioned of destroking to a 302. I'm not looking for 9's in the quarter, but a car that screams and whoops 90% of street cars out there would be enjoyable.

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89 TransAmGTA L98/Auto Grey/Grey T-Tops
Best 1/8th: 9.02 @ 76
89 TransAmGTA LB9/5speed FlameRed/GreyLeather Hard Top

 

BTW...I feel a 383 car will be playing catch up to a properly geared 377 or 327, not the other way around.

 

hey nagga where did u hear that 305 rods are stonger? i thought they were the same as any other small block with a 5.7 stroke?

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86 IROC
43,000 miles
305/700R4/3.23 gears
maroon, gold stickers, black interior, T-Tops.

current mods.
shift kit
headers
cat back exhaust

mods planned for this winter
cam
Adjustable fuel pressure regulator
port and polish intake and heads
lookin to run low 14s maybe squeak out a 13.9 with my stock chip

 

Nope.If both cars weight say 4000lbs and are geard properly the 383's torque is going to leave on you.Oct 2000 Chevy High Performance had a 377-383 shootout.I wish I could scan this and send it to you.Never the less the 377's are sweet.I have built one for a 2900lb 62 Vette and that thing sounds very sweet @ 6900RPM!It has more than ample low end for a street motor and gets on the pipe and runs at about 4500 rpm!

 

this engine builder/machine shop told me that 305 rods are stronger, but they are same size, i guess the metal is stronger, because of where they were made or somethin

 

The rods are exactly the same. The last change in the rods came with the new LT1 engines. The rods are the same size though.

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1989 RS.. 355, Hypereutectic pistons, double roller cam, double roller timing chain, accel wires, blue streak cap and rotor, rapidfire plugs, chevy caprice 350 chip, 200* fan switch, 3 angle valve job, 3 inch cat-back exhaust, 3 core radiator, 3.73 gearing with POSI.

 

305 rods have about 20% less metal in the beams, except for the ones in L69s (and maybe LB9s ?) which are regular 350-type X rods. They are garbage. If you lay a normal 305 rod and a 350 rod side by side and look at them edge on, the difference is immediately obvious. If you cross-sectioned them, you'd see that the "I" shape of a 305 rod is a good 1/16" narrower.

They are, however, the some dimensions where they bolt up to things; their length, width at the journal, diameters, etc. are all the same.

I have a set of LT4 PM rods in my 305 right now... they're far better than the X rods that came in it.

A 383 will outrun an otherwise identical 327 every time. There's no magic that can make up for a 20% increase in displacement. A 327 won't even outrun an equally built 350, let alone an even bigger motor. I don't have to "feel" that, it's just plain common sense. You simply don't get more out of a motor by taking away cubic inches.

377 vs. 383 is a different matter. Those 2 combinations run very close to each other. The 383 will put out a slightly higher peak torque, at a slightly lower RPM; the 377 will put out slightly higher peak horsepower at a slightly higher RPM. Overall there's not a whole lot of difference.

Personally I don't believe I'd be counting on any kind of longevity out of a T-5 with a motor that needed to spin any higher than necessary to make its power. IMHO the combo of a high-RPM motor and a T-5 would be a recipe for lots of trans hard parts replacement.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

Destroking a street/strip engine makes no sense at all. You set a HP or E/T goal and then use the parts that will get you there for the least cost. Anything else is ego(which = squat IMHO). Displacement limits and destoking is for racing series where the rules require it.

Say your goal is 450hp. You don't choose a godd*mn 327 to get there. You will have to rev it to the f*cking moon. Reving to the f*cking moon equals mega expensive parts and less reliability.

Instead you choose a 383 or 400 which will make 450hp with out turning 7500rpms. You make the power at 5500-6000rpms. This is less expensive and more reliable all around.

Just because you engine turns 7500rpms doesn't mean squat. HP is what wins races. Focus on making HP reliably and consistantly, don't get tangled up in who turns the most rpms. That is bullsh*t.

This has all been said in the posts above but I just couldn't contain myself.


[This message has been edited by Brent (edited December 09, 2001).]

 

As for the T-5...I agree. would need to be swapped out. But that requires less thought than the 327 or 377 build up.

As far as torque and all...that's great...but read 1st post. It's not what I want, or was even trying to discuss, My goal is NOT to get the quickest, cheapest way to a hp/et goal. I am working on that with my L98/Auto. PLan to do a 383 when the time comes. But for my manual car, I want a high reving, fast reving motor, that I can drop the clutch at 6-7500 rpm, and take off...would probably get a 4.10 gear or similar, unsure of trans at this time.
I have seen cars with high rpm motors kick the crap out of torque cars 24 hours a day...
I think everyone would agree that gearing is a little more indicative of et anyway...and there is more than one way to get to the finish line.

If I can do what I want to do with a 350, great. If it can be accomplished better with a 327, great. A 377 may be more expensive, and a little harder to obtain...I don't know. I'm not looking to break records, or be the baddest guy in town...just to have fun, and be a little different at the same time. In my opinion, no matter what you do, theres always somebody faster anyway.

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89 TransAmGTA L98/Auto Grey/Grey T-Tops
Best 1/8th: 9.02 @ 76
89 TransAmGTA LB9/5speed FlameRed/GreyLeather Hard Top

 

I plan on strokign my 305

------------------
un4givin89


Poor Mans White Face Guages
MikeKey.net - Camaro Enthusiast

 

I had a post just like this, and everyone started pushing "just buy a 355" I think that what you want to do is cool. There is a reason why the 302 won races, and thats because it was a high revving motor. Everyone thinks having a 56 Chevy or a 67 camaro would be cool, but those cars are all high revving engines (if you haven't swapped it out for a 350).

I haven't destroked the 350, but you may need to look into getting custom pistons made unless they make a kit for it. You probably wouldn't have to worry about new rods or main caps, but if you wanted to do it right then I would replace them. I run my 355 at about 6 grand when I'm at the drag strip and its using the stock rods and the stock caps, still no problems with it.

Keep me informed my man, it sounds like it could be fun.

Lata,
Mike

 

There is something to be said for Horsepower in a high reving motor with a car set up to take advantage of it...

In my father's words

1962 327 Chevy unbeaten for 2.5 years--over 400 races
"whipped 265,,283,, 327,, 350,,396,,427,,--260,,352,,351,,390,,406,,427,,--273,,318,,340,,360,,383,,389,,440,, and afew pieces of crap that were bored & stroked and had 3--2,s and 2--4,s. I had a stock 327, carter 4 barrell, close ratio borg warner, and 355---373---411 gears, with welded spider gears and 6 inch wide cheater slicks, / Driver helps also, NO BRAG, JUST FACT...

After 2.5 years and 400+ wins, a428 or 429 automatic mustang caught me on a bad day and beat me. SO ,,,, I sold my chevy and bought a 1969 ford galaxie 500 with air, no- not ram air ,air conditioning, and retired,LJS"


[This message has been edited by Little GTA (edited December 11, 2001).]

 

302 was built because of displacement requirements. A 350 will rev as much as you want it to. If you want to be different build a 327.


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350 with stealth intake, holley carb, 470 lift cam. 700r4 with .5 boost valve, vette servo, tci lock-up kit, B&M megashifter. Richmond 3.73 gears, powertrax locker, timkin bearings, synthetic lube. Custom 3 inch single into 2 2.5 pipes. 1 1/2 drop springs, 1 5/16 solid front sway bar, 1 inch rear bar, custom subframe connectors, custom LCA relocation brackets. Kobel ground FX, currant red metallic paint. Lots of other stuff...
82camaro

 

Stroke by itself will NOT make a screaming high revving engine. Never has, never will.

You need an intake, heads and cam designed around it. Putting a TPI intake on a SBC 302 would have resulted in an engine that had very little torque in the lower part of the powerband. And then an intake that would have choked off the top end.

A high revving engine wants big port heads with big valves and high flow. Similarly it is going to need a long duration cam. This is what REALLY makes engines like a SBC 302 have so little torque, when combined with the short stroke.

Altering stroke by itself has minimal effect on an engine's ability to generate HP or rev. It has a direct effect on torque and will alter the rpm level peak HP is attained. But it WILL NOT make a high revving all by itself.

Though I don't put too much weight to the actual numbers generated by a program like "Desktop Dyno", it will give you an idea on the effects to HP/TQ at various RPMS. I do recommend that you get access to a program like "Desktop Dyno" and put some combos together and see what happens to the torque and HP. I think you will be surprised. Also, you will see what is needed to make your combo work.

Remember though, that you may end up with a combo that cannot run on pump gas. So be careful that you don't come up with a combo that is "race only" or has an "on-off type throttle".

PS: AMC also won the last of the Trans-Am series. Their engine was a narrow bore/long stroke combo compared to the Ford or Chevy. Also, the Boss 302 had Cleveland heads IIRC. Great race motor, but no bottom end torque. I had a buddy that owned a Boss 302 and it was not a fun car in traffic.

[This message has been edited by Glenn91L98GTA (edited December 10, 2001).]

 

Thanks Glenn. I was gonna right something to that effect, but I'm not as good with words as you are.

I used to have a 72 Nova w/350,the old 462 "Camel Hump" heads-ported and polished. A Crane 302 solid cam with .510" lift, a Holley highrise single plane intake, and a Holley 4150 on it. It had the close ratio M21 4spd with 3.36 gears in the back. I know those seem like high gears, but it only had 235/60/R14s on the back. Pizza cutters. And the car only weighed about 3200 lbs.

You had to be above 3500-RPM before it had any ***** at all. But once it did reach the right RPM, look out!!! It was kinda good for street since it had an open diff. and was easy to take off from a light under normal driving because of the lack of low RPM torque.

And that was the best part. You could take off at ~1500-RPM, then jam the pedal down, and it was fine. But right at 3500 RPM, the right rear was screaming for mercy!!!!!

But like you said, that had nothing to do with it being a 350. Just the cam and intake. I'm sure those heads were sufficating the engine a little, but it would still pull strong up to 7000RPM. It was fun!!!!!!!

Anyway, if it was a 327 with that same cam, intake, and heads, I would've had to take off at 1800-2200 RPM just to get the car moving, but by then the RR tire would be swarming in a cloud of smoke. The car would've had even less torque down low, and that would've required at least a 3.73 gear. Just not practical for the street. And the upper RPM would have suffered also just because of the lack of CID. The 327 would flow less air overall, which we all know equals less TQ and HP.

I guess it should all be based (as someone said before) on the weight of the car you put it in. A 3500+lb. car like ours, needs that low end grunt for street driving. I mean you can put a 302 in there with peak TQ @ 5500 RPM, but your gonna need a 4500-5000 stall TC, and 3.73-4.10 gears. Even then you still won't have the same TQ output as a 350 at 5500 RPM with the same cam, intake, and heads. It just won't happen.

Put a 302 in a sprint car (AKA Chevy Sprint) or a dune buggy (AKA Honda, Del Sol), or maybe even a Vega, and you'd have a cool little set up for a road-race course. But don't expect it to work well in a 3500lb. car!!!!! It ain't gonna happen.

AJ

[This message has been edited by AJ_92RS (edited December 10, 2001).]

 

See sig for my opinion........

------------------
1987 Black 305 TPI 5spd IROC, G92, 9-bolt 3.45, Lowered, Cat-back, Air Foil, Sub Frames, Huge sways

"YOU All Laugh Because I'M Different, I Laugh Because YOU'RE All The Same" - me
AIM: IROC 5spd
http://www.geocities.com/chevy5spdiroc/87Roc.htm

 

Actually, there is something no one has mentioned in this "high revving engine" formula, that you'll need a solid cam.

I never owned a SBC with a solid cam, so I cannot comment on how difficult or how frequently you need to do it. But I did own a Triumph TR-6 which did have solid lifters. I remember having to adjust those every month if I wanted my TR-6 to run properly and not prematurely need a valve job. With the inline 6, it wasn't that difficult to do. But it still got to be a pain after awhile of owning the car and the stupid "cork" valve cover gasket meant having to always replace the damn thing.

I better shut up before I start to get my blood boiling over that stupid car. Crappy electrical system that constantly was shorting out, a cartridge oil filter with an O-ring that leaked half the time, cable windshield wiper system that constantly needed repair, and screws that constantly needed to be tightened ... and the car wasn't even 3 years old when I dumped it on someone else.

I know why Triumph went out of business.

 

Say Glenn,
The Desktop Dyno your refering to...IS that the program available from Mr. Gasket. I was thinking about buying that and the other drag 2000 (?)... Are they transferrable too...meaning can you take a motor you design, and simulate how it will perform in a car with theoretical gearing , weight, and such?

Thanks for the answers too.

Instead of destroking the 400...would it be wise to make a high revving 400? And still be manageable on the street?

 

I don't have or use Desktop Dyno myself. I have access to a different program from an engine builder.

However, in talking to a friend that HAS Desktop Dyno, it appears the newer version has a lot more "inputs" to give a more accurate reading than in the past.

While my engine builder friend says his program actually gives very similar results to actual engine dyno readings he's obtained, I don't pay too much attention to the ACTUAL HP/TQ. What I do pay attention to is the CHANGE to HP/TQ from different head, intake and cam combos (one change at a time).

I am currently looking to install a Miniram, professionally ported aluminum L98 heads with a cam of 214/222 @ .050. I also have the opportunity to get an LT4 Hot Cam. I plugged in BOTH cams (all else being the same) and found the LT4 only gave a couple of HPs more but I lost BIG TIME on the low-mid range torque. The limiting factor is the flow of the heads. With different heads, the LT4 Hot Cam would be a better cam. Just not with the combo I am looking at.

And that is the whole point RB (and others) are trying to impress upon people - you need a MATCHED combo. RB has actual "hands-on experience" in this matter. I have had a number of friends that have made similar mistakes in the past also. These "Desktop Dyno" programs just further confirm what they are saying/experiencing.

Again, don't pay TOO much attention to the actual HP/TQ numbers they generate. You will only find that out by an actual dyno run. The HP/TQ can change dramatically based on the tuning you do to your engine. If you have tuned it correctly, you probably will exceed the "generated" numbers. Tune it poorly, and you'll be lucky to see anything close to those numbers. Instead, pay attention to the changes to HP/TQ when you make a change. That will let you know if it is a "good" change or a "bad" change.

 

Might as well buy a new L98 shortblock instead. With internal balancing, no machining costs, everything else bolting up to the block without modification or changing, it will cost you less in the end and you'll have more displacement.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4, 2300 stall TC. Ported World 305 heads, Crane PowerMax 2050 cam. ZZ3/4 intake, oil pump, pan & baffle. Accel HEI SuperCoil & module. Hooker 2055 headers, 3" Catco cat & 3" catback w/dual-opposite Flowmaster 80. 2.93 limited slip. Spohn SFCs waiting to be installed. AMSOIL syn lubes bumper-to-bumper. Daily year-round driver. Best ET, speed TBD...
57 Bel Air, my 1st car. '66 396, 9.7:1 forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 700 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

The solid cam wasn't bad in that car. No EGR, power steering or brakes. No emissions crap. All it had was an alt & water pump. Raw HP Baby!!! Thank GØD for rubber gaskets though.

I set the valve lash every 2K miles when I changed oil. I was young, dumb, and full of.....well you know. Bad car for every day driving, so I only used it for fun. But even that was quite often.

The worst he valve lash was ever off was about .002-.003". And that was the worst out of 16 valves. But it was a pretty mild solid cam.

I just used the 'ex. barely open-do the int. & int. almost closed-do the ex.' trick. I can't imagine doing that in our cars. I suppose if all the emissions crap was outta the way, it'd be OK. And how you gonna pass the sniffer with a soid cam anyway.

So to answer the question, the 327 is a nice motor if it's an original, and made for an original resto project. But I think if you're gonna destroke something, do a 305. Or better yet, a 267!!! Bore it .030" over and use a crank from a 265 and you'd have a 235cid. Then it'd be neat. A nice econo engine with a little power up high for running in a econo-box car on the highway.

AJ

[This message has been edited by AJ_92RS (edited December 11, 2001).]