Building a 265 for my 55 Chevy

B

bfalfa55

Member
WHY ? Oh why not ! I know "no replacement for displacement" but I like the challenge. Here is the quick story. I actually have the original 265 my dad removed from his 55 in 1960. My father, son and I were going to build it as a fun project to see what we could make of it with modern technology (roller cam, better heads, possible power adders). In the process of drumming up parts I found (2) different 56 265 short blocks and these blocks are a better start for performance. First short block was a wallet killing $100 with old JE cast dome pistons and a fully balanced rotating assembly. Found out one piston was cracked. This lead me to the short block I am going to use. It is a fresh, .060 over, standard deck height, never run, +6cc domed pistons, full race prepped block built to take 10,000 RPM. With it I bought a set of 461 1.94 heads for another wallet killing $500 ! I am going to run this Howards cam: http://www.summitracing.com/parts/hrs-c ... /overview/. It shows some very good Hp and torque numbers for a 265 upwards of the 6000-6500 RPM range unlike the 800-4,200 range it show for a 350. I have the option of 3 sets of heads in my possession. 1 - 461, 64cc 1.94/1.5 heads (these heads have all the porting and bowl work done but need to be cleaned and re-assembled AND the block has unshrouding on the top of the cylinders to acomodate the 1.94's), 2 - 416 casting, 305 heads with 58cc chambers, 1.84/1.5 valves these need to be ported, bowl work and rebuilt) and 3- 601 casting 305 heads with 53cc chambers, 1.84/1.5 valves ( these heads could be used as is but they are not ported or worked on yet). Looking through the TONS of links GrumpyVette has listed on Chevytalk, I ran different numbers to come up with my Dynamic comp. ratio, knowing this is more important than the Static ratio.I can run from 9.48 to 11.17:1 for compression with the thinnest head gasket. the 9.48 is the 1.94 64 cc heads, the 11.17 is the 1.84 53cc chamber 305 heads. I would have a dynamic ratio from 8.03 to 9.45, dynamic cranking pressure from 160 to 197. I think the 9.45 dynamic will put me in the race gas only area unless any of you know otherwise. I am trying to make my 55 a modern day "dual purpose" car but based on the times. I want to drive it to the track and have a solid mid 13 second car. I am in contact with a Nostalgia Super Stock guy who runs a 55 and he feels this goal is no problem with the use of modern parts instead of an old school build.
Everyones input welcome, especially you Grumpy !
 
well, if your goal is to have a dead nuts reliable 13 second car then i think you are well on your way, however i think we are gonna need some more details about the setup:

how much does it weigh (with driver) ?

what transmission will be used?

what rear end will be used?

what gears in that rear?

how tall a tire out back?

what suspension is in the car (leafs, four link, ladder bar)?

whats your intended rpm range?

with the stock 3" stroke of the 265 you can turn out alot of rpm before reaching piston speeds that would make people deem your combo as anything but reliable. in the chassis your working with, i assume its gonna be alot like powering a crown victoria into the 13's with a 5.0 motor. it can be done and you arent in uncharted waters. if the reason for the guppy motor is the mere availability and the cheap cost i can only advise you one thing... try not to speend too much money on anything you cant use later when you undoubtedly will go with a bigger motor. we all know how this story ends, we go fast with the 265, we build outselves a 383 on the side, we haul ass with the 383 while we build a 496.... we all fall down this rabbit hole... dont feel bad, embrace it as most of us have haha and dont forget to have fun and enjoy the ride
 
Believe it or not, I'm not falling in the rabbit hole. This is all for the challenge and for the fun. With modern roller cam grinds, these little engines can perform much better than the old days. If you have a dyno program, put this cam in it with a .060 over 265 and play around with some numbers. I know it will never have torque and P numbers like a 383 but I think you will see some impressive numbers coming from the small package for what it is. I want something that is fun enough drive, fast enough to enjoy and driveable enough to be able to go to any track or show I want without breaking the bank. I could build up my 350 but I am just trying to be different. I would do it on the cheap anyway because I am a cheap ##s ! For the going faster thing, we will probably build a full on race car later. The 350 in it now that my dad and I built 25 years ago. Strong runner, easily a high 13 second car (ran a 14.06, 98 MPH, with a soft launch, on pump gas and no tune. Here is the answers to your questions. I knew you would ask but I didn't want to write a book the first post !
weight(with driver and some gas): 3,150
Transmission: Super T-10 with a 2.64 first gear (future upgrade to a steeper first gear and/or a 5 speed with a steeper first gear and overdrive for driveability)

Rearend: Original type 55-64 rearend for now. (I know they don't take tons of abuse, future has a 9 in.)

Gears: 3.70, They are the actual gears my dad ran in his 55 in the early 60's. Won't do a gear change for with this rearend unless I get them super cheap or free. I will save the gear change money for the 9 in.

Rear tires: Not for sure yet but they will be in the range 27-31 tall. I know this will effect the gear ratio but I have a big wheel well openings to fill. Too small will look funny. This is the only somewhat "cosmetic" part I am thinking about that I know I will have to contend with to reach my goal.

Suspension: 5 leaf springs with bolt on (not slapper bar) traction bars. Proper length bars that actually have the snubbers under the front spring eyelet.
 
lets go thru some basics here , the main potential advantage of building a SBC with a 3 inch stroke is its potential to use its short stroke and allow the engine to reve without exceeding reasonable stress levels you could figure about 4200 feet per minute, thats 8400rpm which is well past hydraulic lifter range and well up into solid lifter territory.
you can calculate the port cross sectional area and cam duration lift and header design, and cars gearings reasonably well doing a few searches on the site , but your basically going to want to maximize performance in the 5800rpm-8000rpm power band, and youll need a serious cam with a good deal more duration than the one you linked too, and a good deal more static compression to use it effectively, why not start by calling CRANE,CROWER,ISKI and ERSON, and asking what cam they would suggest you use, with those 461 heads and about 10:1 compression.(10.5:1 would be even better) so milling the block or heads or both might help.

viewtopic.php?f=52&t=8460

http://www.wallaceracing.com/runnertorquecalc.php

http://www.wallaceracing.com/chokepoint.php

just throwing some old school parts together in DD2000., ported fuelie heads, similar to yours but reworked, open long tube headers, a crane 114681 solid lifter flat tappet cam,
http://www.summitracing.com/parts/crn-114681
1.6:1 ratio erson rockers, a decent intake like this edelbrock, and hooker headers
http://www.summitracing.com/parts/hok-2456-1hkr
http://www.summitracing.com/parts/edl-2925
Id be using a manual transmission, a 35 lb fly wheel, and 4.56:1 rear gears , good slicks, caltrack traction bars
hly-0-4778c_w.jpg

a 750 cfm carb
http://www.summitracing.com/parts/HLY-0-4778C/
hok-2456-1hkr_w_xl

EDL-2925_xla.jpg

caltracfirebird.JPG

265fg.png

figure a conservative 360 rear wheel hp and a car weight of 3500 lbs that puts you where your goal is
http://www.race-cars.net/calculators/et_calculator.html

( an engine built like that would not be designed to run well on the street in traffic but it would run reasonably well in its intended power band 5800 rpm-7500rpm)
 
I am using the same DD2000 you have and have obviously overlooked entering something. Just so you know, I didn't just willy nilly guess at this cam but have most likely based it on eroneous data. It's no big loss if I can't use the cam. My son and I can save it for a future project or I will just sell it again. I got it for very cheap and can likely make money on it when I sell it. If you can, put the cam data for the one I listed in DD2000 so I can compare it to mine so I can see what I did wrong.
 
THIS ENGINE BELOW IS MORE OF A STREET ENGINE NOT SOMETHING THAT RUNS 13 second times, in your average 1955 chevy
hows.png

I removed my cam data and entered your cams timing specs, and removed the roller rockers everything else remained the same, as youll see, as expected, due to the lower lift and duration, and a reduction in potential air flow rates in the upper rpm ranges ,due to the limited valve duration limiting that air flow, a gain in off idle torque in the lower rpm range and a loss in upper rpm power resulted from the shorter valve timing, because theres no way that short duration and a roller cam can keep breathing well past 5500rpm, but the earlier valve close event traps more cylinder volume at lower rpms thus more effective low rpm torque, the listed specs posted earlier are very similar to previously built 283 engines that ran very well

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postiongraph.jpg


viewtopic.php?f=52&t=333

viewtopic.php?f=52&t=82

http://www.camquest.com/

USE THIS CAM SELECTION SOFT WARE

ENTER
265 displacement
enter pro street/mild race
solid lifter flat tappet
3500 car weight
carbs

THEN GO TO THE DYNO OPTION
ENTER VALVE SIZE 1.94/1.5
compression 10.5:1
open small tube headers

youll see you get a cam with similar duration as I suggested
look I have built a few 283 engines and they can be made to scream if you do decent head prep and use similar components to what I suggest, but it won,t be ideal for street driving or great mileage, but it will be fun to drive if you can shift well, and for damn sure get a blow proof clutch and lakewood bell housing , ignition with a reve limiter and a set of roller rocker and a rocker stud girdle
 
I don't have all the flow files and data files you seem to have. I got very different numbers. I entered all the same things you did but didn't have the flow numbers and also realized I had it entered as seat to seat, not @.050. Do you get false data if you don't have true flow numbers ? No big loss, no real money spent. I paid $130/shipping included for the cam. Sell or future project. There is still plenty of work to do and I can take my time as I will still be able to drive my car until I get the engine done. I do consider myself good at shifting and I have a 55-57 Lakewood bell housing specifically for this engine sitting in the corner of the garage. I like my toes and feet !
 
Hey Grumpyvette, being that you have probably used Desktop Dyno plenty of times for your engine builds, how accurate are the numbers percentage wise ?
 
peak hp and tq, numbers tend to be within 5%-7% of those predicted if you carefully enter data, torque numbers predicted especially at lower rpms are a wild ass computer fantasy, guess in my opinion as I see measurably different results in either direction at times
 
Here's what Mike Jones from Jones Cams recommended:
Cam# SBCH, H70330-72330-108
224/228 @ .050"
.330"/.330" Lobe Lift
.495"/.495" Valve Lift
108 LSA
Price: $249.69

Lifter# J842H
.842" Hydr F.T. lifter set
Price: $89.83

Spring# JRC15
1.250" Single Spring w/Damper
130# @ 1.750", C.B. 1.160"
Price: $92.00

With the blower, I would change the cam to,
Cam# SBCH, H70330-72334-110
224/232 @ .050"
.330"/.334" Lobe Lift
.495"/.501" Valve Lift
110 LSA

What do you think about these GrumpyVette ? I have also contacted other cam companies with as much detailed info. as I can to see what they suggest.
 
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