488 Eagle stroker kit
#41
I've seen it, and the difference was minimal.
Correct me if I'm wrong, but you're saying 8 ring packs scraping a splashed bore have less drag than rod bearings that are riding on an oil film? Interesting.
Correct me if I'm wrong, but you're saying 8 ring packs scraping a splashed bore have less drag than rod bearings that are riding on an oil film? Interesting.
Last edited by fleming442; January 6th, 2022 at 07:50 AM.
#42
Well I can compare my F/SA 315 HP NHRA stock 10.67 compression 455 Buick with cast iron intake and Q-Jet and .398 lift hyd flat tappet cam, 2.005 Intake valve in my stock cast iron heads to your 455 Olds combination. Not sure where your at now, but I've run 10.70s @ 3650 pounds.
Another comparison: In NHRA stock the 1970 W30 455 Olds run in D/SA which I've seen some 10.40 runs
In NHRA stock the 1970 stage 1 455 Buick runs in C/SA one class lower than the W30, but I've seen 10.00 from that combination
Bottom line: I'am not a Buick fan, but its bigger bore does have an advantage, I don't know if you can say the production Buick head is better, but you can get a bigger valve in there, hopefully you will look at this objectively. In the near future when I get caught up my plan is build a 455 Olds and run it in my Buick, it won't be any thing hi dollar just mainly production parts, but I will be looking to run 10s.
Another comparison: In NHRA stock the 1970 W30 455 Olds run in D/SA which I've seen some 10.40 runs
In NHRA stock the 1970 stage 1 455 Buick runs in C/SA one class lower than the W30, but I've seen 10.00 from that combination
Bottom line: I'am not a Buick fan, but its bigger bore does have an advantage, I don't know if you can say the production Buick head is better, but you can get a bigger valve in there, hopefully you will look at this objectively. In the near future when I get caught up my plan is build a 455 Olds and run it in my Buick, it won't be any thing hi dollar just mainly production parts, but I will be looking to run 10s.
#43
#44
We make due with what we have to work with.
#45
#46
No you wouldn't, but certainly @ 5100-5200 RPM peak HP is good for nothing in my opinion, and I've seen that a lot with your builds, if you could raise the peak above 5700 it would certainly be a better combination IMO. And then there something we really have not talked about on this forum, and thats power carry, I'am always trying to build a engine that carries power past peak with out falling off hard, more gear, more converter, quicker car.
#47
No you wouldn't, but certainly @ 5100-5200 RPM peak HP is good for nothing in my opinion, and I've seen that a lot with your builds, if you could raise the peak above 5700 it would certainly be a better combination IMO. And then there something we really have not talked about on this forum, and thats power carry, I'am always trying to build a engine that carries power past peak with out falling off hard, more gear, more converter, quicker car.
#48
This is all good discussion, but the OP stated he is interested in a street car 5500 rpms, maybe track 2x per year.
we have a lot of members focused on racing and a lot of members that enjoy street performance too.
as a non drag racer i wont rev past 5kish in my bbo because theres less power there and i have no interest in testing its rpm limits.
on the street I dont mind playing around and sliding it sideways, doing a burnout, or stoplight to stoplight acceleration all thats needed is good
torque and hp in the typical driving rpm range of 2-4k rpms.
we have a lot of members focused on racing and a lot of members that enjoy street performance too.
as a non drag racer i wont rev past 5kish in my bbo because theres less power there and i have no interest in testing its rpm limits.
on the street I dont mind playing around and sliding it sideways, doing a burnout, or stoplight to stoplight acceleration all thats needed is good
torque and hp in the typical driving rpm range of 2-4k rpms.
#49
The post above is a good example of pros and cons coming into play. For a street engine the long arm is a PRO. It adds CI. The more CI the higher demand in the cylinder. This coupled with the rather smallish port will yield excellent low speed torque. A CON would be the increased CI will not be as fuel efficient. It would take pages to get to all the details.
#52
Long rod vs short rod has more to do with non tangential load. This means that the force transfered to the crank is greatest when the load is 90° to the crank. The shorter the rod move that event earlier. Depending on the application and the speed the motor is operating at it can make a difference. On a dyno you might not see a significant change but real word dynamics it can be useful.
#53
The difference in rod angularity between the 488 stroker and a stock 455 are very small .
the rod ratios are near identical at 1.58
When the crank is at 45deg, the 488 piston is only .050” further down the bore than the 455
At 90 deg, the 488 is .150” further down… the rod angularity difference at those two spots between the two is slight.
the 1.58 rod ratio for 488 , same for the 496, isn’t bad. The stock 454 chev rod ratio is 1.53!!! That’s horrible, what were they thinking ??
that’s some serious rod angularity issues there.. it’s probably why they have longevity issues and beat the hell out of the cyl walls and skirts. Bad deal on them hunks of sheeet 😁
the rod ratios are near identical at 1.58
When the crank is at 45deg, the 488 piston is only .050” further down the bore than the 455
At 90 deg, the 488 is .150” further down… the rod angularity difference at those two spots between the two is slight.
the 1.58 rod ratio for 488 , same for the 496, isn’t bad. The stock 454 chev rod ratio is 1.53!!! That’s horrible, what were they thinking ??
that’s some serious rod angularity issues there.. it’s probably why they have longevity issues and beat the hell out of the cyl walls and skirts. Bad deal on them hunks of sheeet 😁
Last edited by CANADIANOLDS; January 10th, 2022 at 02:30 PM.
#56
lots of post following his question, I did not see it get answered.
#58
Your 10:1 496 street build
Ive used the eagle 4.5" crank in a couple of 496 builds. one was 14:1 with a big roller cam and steel rods, the other was a 10:1 street engine flat tappet making about what you plan on making. both are still in one piece with lots of runs and street miles on them.
they are not turning a lot of RPM's. maybe 6500 max for the one and under 6k for the street engine. they both have main cap support, thats a must which you need to have if you want it to live.
the eagle cast steel crank has a higher carbon content than iron cranks which is why they can call them steel.... heres the tensile strength of some crank material
cast grey 70,000 to 80,000
cast nodular 95,000
factory forged 10xx series 100,000 to 110,000
cast steel 105,00 to 110,000
5140 forged 115,000
41xx series forged 120,00 to 125,000
4340 series forged 140,000 to 145,000
notice the tensile strength of the factory 10xx forging and the 5140 are very similar to the cast steel...but the forgings are much stronger because they are less brittle and have higher elongation properties
the only thing i found with the eagle cranks i used was their main and rod dimensions were right at the high side. which meant i couldnt get the clearance i wanted using standard bearings. so i had them ground under to my dimensions and used .010' bearings. im not sure if they fixed that but it was a know problem if you wanted more clearance
i know of a few 496's running hard with the factory nodular crank...done right and nitrided, they can work
they are not turning a lot of RPM's. maybe 6500 max for the one and under 6k for the street engine. they both have main cap support, thats a must which you need to have if you want it to live.
the eagle cast steel crank has a higher carbon content than iron cranks which is why they can call them steel.... heres the tensile strength of some crank material
cast grey 70,000 to 80,000
cast nodular 95,000
factory forged 10xx series 100,000 to 110,000
cast steel 105,00 to 110,000
5140 forged 115,000
41xx series forged 120,00 to 125,000
4340 series forged 140,000 to 145,000
notice the tensile strength of the factory 10xx forging and the 5140 are very similar to the cast steel...but the forgings are much stronger because they are less brittle and have higher elongation properties
the only thing i found with the eagle cranks i used was their main and rod dimensions were right at the high side. which meant i couldnt get the clearance i wanted using standard bearings. so i had them ground under to my dimensions and used .010' bearings. im not sure if they fixed that but it was a know problem if you wanted more clearance
i know of a few 496's running hard with the factory nodular crank...done right and nitrided, they can work
#59
it’s a comp solid flat
Iron heads, 3600 lbs+ 10.5’s at 133
it’s not 10:1 , a lot more than that
#60
I can understand that, was trying to get an idea if i should upgrade to a roller cam or should i stay with a flat tappet. Im liking those numbers, im hoping to be at or near 600 lb-ft & close to 500hp with my 496.
#61
Well, then share what you used for the 10:1 engine and keep the secret about your "a lot more than that" engine.
#62
#63
The last one I did had out of the box Gen II Edelbrocks, 10.25:1 and an RPM Air Gap. Made 585/640.
#64
I routinely give duration numbers because there’s very little chance of anyone picking the exact same lobe that I do. I use Comp cores. But between Lunati, Comp, and now the old Crane stuff that’s been integrated in, it would be that much more difficult to grab the exact same lobes.
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