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Dan and Bill have already posted this on FB but thought I'd put it here as well.
403 block with one of my 4.00" stroker cranks. BTR built with BTR Girdle and BTR ported Edelbrocks. Port matched Victor, 850 QF, 10.7:1, hyd roller running solid roller lifters. Not bad for a "Small Block" Olds huh?
Last edited by cutlassefi; Jan 14, 2020 at 04:45 PM.
Great numbers, but how long will the 403 block last at that RPM? I know it is girdled and all but 6500?
With the full girdle and a really strong and stiff crank it'll be fine. Bill thought enough of the rod and crank combo to want to take it to 7K. But it quit making power before that anyway so...
This crank is lighter, internally balanced, and about 30% stronger than a 330 crank. That helps everything.
Last edited by cutlassefi; Jan 14, 2020 at 05:01 PM.
That has to be the best HP out of a 403 yet.
Congrats Mark, Bill and of course, Dan M.!
Apparently they weren't done yet So much for a smaller carb making more low end power huh guys? That's a farce more often than not. It picked up everywhere with the larger carb.
Last edited by cutlassefi; Jan 16, 2020 at 03:16 PM.
Mark, dish with the details, man! Piston dish? Head cc? Lobe profile?
Cam was spec’d by Bill but I know it’s a Comp hyd Roller, 242/248@.050 on a 108lsa. Bill uses that cam in a lot of stuff.
Pistons were custom CP’s, dish was enough to make 10.7:1 with 70cc heads. Valves were 2.160/1.68.
Could've used more cam for sure, or at least a wider lsa imo.
The final cost would give one, "heart pulpatations." I'd shift it at 5,400 and let it run trough the traps at "whatever" but that's just me. Lighter the car the better.
No one should be surprised, I've never liked the small bore, long stroke 455 combination. The 403 block gives you a 4.351 bore standard, opens up to take a big intake valve, short stroke, small main journal, combined with a ported aftermarket head that will make power past 5200 RPM. 484 inches, big bore, solid roller, aftermarket heads, I would expect this kind of power. Does any one know if the block was filled? Measured HP was 630.
Last edited by VORTECPRO; Jan 17, 2020 at 06:37 PM.
The final cost would give one, "heart pulpatations." I'd shift it at 5,400 and let it run trough the traps at "whatever" but that's just me. Lighter the car the better.
You mean you wouldn't leave @ 5800 RPM on the trans brake.........
Would that even do anything to support the windowed mains and keep the crank attached to the block?
No. The filling is above the main webs. More to the point, the epoxy used to fill the block is considerably less stiff than the cast iron, so no load gets transferred. In the same way that electrical current takes the path of least resistance, load is always transferred through the path that is stiffest.
IF (and that's a big "if") filling the block helps minimize or damp cyclical deflections and thus mitigate fatigue loading and crack propagation, then there MIGHT be a minor benefit, but don't count on it. As Mark noted, there's a full girdle. This is what increases the stiffness and strength of the bottom end. And don't confuse "strength" with "stiffness". They are two different load cases that frequently require different structural solutions.
Do I dare bring up mention of the Chrysler 392 hemi? That was a window main block that was raced by many top gas and top fuel racers and held together because of the girdle and the fill; many were used in tractor pull as well, and these motors had a roots blower on top. Kudos to ya Dan. Anxious to see how she performs!
Do I dare bring up mention of the Chrysler 392 hemi? That was a window main block that was raced by many top gas and top fuel racers and held together because of the girdle and the fill; many were used in tractor pull as well, and these motors had a roots blower on top. Kudos to ya Dan. Anxious to see how she performs!
I for one was unaware the 392's had a windowed block. They were cast in a different era when engine weight wasn't a factor. It doesn't surprise me that they used a girdle back then. I am sure the 371 and 394 Olds engines also had a girdle. Obviously, a girdle is a major benefit to reliability and power output.
IF, a stout girdle and crank could be manufactured at a "fairly reasonable" cost, 403's could become more popular. The bore size of the 403 has always been attractive, but the windowed mains have been the weakness. If Oldsmobile had cast a strong block in the 403, they could have upped the displacement "strokers" and we could have had a monster 442 engine.
......Just my two cents worth.
No. The filling is above the main webs. If people were a bit more observant they would see the cyl skirts on a 403 go below the rest of the block, hence block fill would have minimal value in relation to main web stiffening as Joe said. More to the point, the epoxy used to fill the block is considerably less stiff than the cast iron, so no load gets transferred. In the same way that electrical current takes the path of least resistance, load is always transferred through the path that is stiffest.
IF (and that's a big "if") filling the block helps minimize or dampen cyclical deflections and thus mitigate fatigue loading and crack propagation, then there MIGHT be a minor benefit, but don't count on it. As Mark noted, there's a full girdle. This is what increases the stiffness and strength of the bottom end. And don't confuse "strength" with "stiffness". They are two different load cases that frequently require different structural solutions. Correct, anyone ever seen how they test airplane wings, scary!
I have a pic of the girdle as it was installed. I'll try to find and post it. With that said this was a great leap for the 403. As I've said before, the Olds small block ain't dead.
Last edited by cutlassefi; Jan 18, 2020 at 02:43 PM.
I have a pic of the girdle as it was installed. I'll try to find and post it. With that said this was a great leap for the 403. As I've said before, the Olds small block ain't dead.
I think for a short period after the Rocket aftermarket block became available the general focus was on this amazing block.
The small block will always have its fan base. I still think the 350 is Oldsmobile's best engine design from the era that made it to production.
I hope DR Dan's build can hold up to track use like his other builds.
I think for a short period after the Rocket aftermarket block became available the general focus was on this amazing block.
The small block will always have its fan base. I still think the 350 is Oldsmobile's best engine design from the era that made it to production.
I hope DR Dan's build can hold up to track use like his other builds.
Its too bad they windowed the mains like that, I always had my eye on that block until someone pointed out the main saddles. The more I look at that 403 block, the more I think those windows can be welded up,
Last edited by VORTECPRO; Jan 18, 2020 at 04:48 PM.
Its too bad they windowed the mains like that, I always had my eye on that block until someone pointed out the main saddles. The more I look at that 403 block, the more I think those windows can be welded up,
That would be a cool build.
There was a RealOldsPower member that built a one piece lower block support that was very cool it also survived the dyno pulls.
I don't know what happened to that build.
I hope Dan's build lasts as long as his other 403 builds.
The question for the small block fans is does it make sense to build a stroker DX or Nascar block with a smaller bore.
I think the reason Dan built the 403 is because he has had success and is also big supporter of the engine. He took a lot of flack from the haters for his engine choice at one time.
