403 ?
#1
403 ?
I have a 403 I pulled from a 79' Trans Am, and I'm not sure if its concidered to be a Small or Big block. I have a 455 and for the most part they look reletivly the same. Anyway this 403 is going in a 1972 Olds Cutlass now and I want a good engine recipe for it. The objective is to Turbo Charge this engine and also add the 442 hood and utilize the air damns. If you have any answers or ideas plz lemme know thanx for your time.
#2
I have a 403 I pulled from a 79' Trans Am, and I'm not sure if its concidered to be a Small or Big block. I have a 455 and for the most part they look reletivly the same. Anyway this 403 is going in a 1972 Olds Cutlass now and I want a good engine recipe for it. The objective is to Turbo Charge this engine and also add the 442 hood and utilize the air damns. If you have any answers or ideas plz lemme know thanx for your time.
The 403 has the dubious distinction of having windowed main webs. Under high cylinder pressures and high RPMs, this can cause the engine to spit out the crank. A much better choice for a turbo motor would be a diesel block.
#3
403
I want to know if this is a good engine recipe.
1. 403 block bored .030 over (409)
2. 403 crank ground down .010
3. 350 heads from a 72 Cutlass
(How do I tell if they are 7a heads easily?)
4. stock 403 rods
5. deck the heads .030 over for a 10.1 c ratio
6. .040 head gasket
7. 2.072" valves from a W30
8. Bore cooling holes in the 350 heads to match the ones in the 403
9. Crane lifter, pushrods and springs
10. Edlebrock Performer Rpm intake (7111)
11. Holley 750 electric choke
12. Msd distributor and external coil pack
13. TH-350 tranny, 2500 stall conveter, B&M Shift kit
14. 3.08 posi in the back
1. 403 block bored .030 over (409)
2. 403 crank ground down .010
3. 350 heads from a 72 Cutlass
(How do I tell if they are 7a heads easily?)
4. stock 403 rods
5. deck the heads .030 over for a 10.1 c ratio
6. .040 head gasket
7. 2.072" valves from a W30
8. Bore cooling holes in the 350 heads to match the ones in the 403
9. Crane lifter, pushrods and springs
10. Edlebrock Performer Rpm intake (7111)
11. Holley 750 electric choke
12. Msd distributor and external coil pack
13. TH-350 tranny, 2500 stall conveter, B&M Shift kit
14. 3.08 posi in the back
#5
What pistons and cam are you using? I would deck the block instead of milling the heads. That way you can re-use the heads and it also improves quench. Some stock replacement pistons sit as low as .050 in the hole. Also, I believe that #8 on your list is not necessary, but not certain about that.
#6
Waste of money. The HEI, that came with the engine, is more than adequate for anything less than a racing engine.
It is not possible to advise you, in any of the other areas, without knowing about your actual goals, budget, expectations, driving habits, etc.
Norm
It is not possible to advise you, in any of the other areas, without knowing about your actual goals, budget, expectations, driving habits, etc.
Norm
#7
I want to know if this is a good engine recipe.
1. 403 block bored .030 over (409)
2. 403 crank ground down .010
3. 350 heads from a 72 Cutlass
(How do I tell if they are 7a heads easily?)
4. stock 403 rods
5. deck the heads .030 over for a 10.1 c ratio
6. .040 head gasket
7. 2.072" valves from a W30
8. Bore cooling holes in the 350 heads to match the ones in the 403
9. Crane lifter, pushrods and springs
10. Edlebrock Performer Rpm intake (7111)
11. Holley 750 electric choke
12. Msd distributor and external coil pack
13. TH-350 tranny, 2500 stall conveter, B&M Shift kit
14. 3.08 posi in the back
1. 403 block bored .030 over (409)
2. 403 crank ground down .010
3. 350 heads from a 72 Cutlass
(How do I tell if they are 7a heads easily?)
4. stock 403 rods
5. deck the heads .030 over for a 10.1 c ratio
6. .040 head gasket
7. 2.072" valves from a W30
8. Bore cooling holes in the 350 heads to match the ones in the 403
9. Crane lifter, pushrods and springs
10. Edlebrock Performer Rpm intake (7111)
11. Holley 750 electric choke
12. Msd distributor and external coil pack
13. TH-350 tranny, 2500 stall conveter, B&M Shift kit
14. 3.08 posi in the back
All of this is useless if you're running a stock cam. You didn't mention one, so we can only assume.
#8
If you want to see a lot of different engine builds, all with different goals of course; you can go over to Realoldspower.com and navigate to the sub-forum on engine builds. There are LOTS over there and you can make all the comparisons you wish. I am not saying our site cannot help you but I am just aware of that option and want to offer any help I can. Those posts on that forum often have comments about drive-ability vs. cost vs. power etc. Norm is right however, you need to consider your goals before anyone can truly say if that build you are considering is good or not and Harris has a valid point too, you didn't mention a cam which determines all the other valve train components in some cases. Good luck.
#9
I did some research into building a 403. I read that they were notrious for overheating. You will want to drill out the 350 heads to match the coolant passages for the 403 deck. I have also heard that it is a good idea to tap the head bolts out for 1/2" ARP head bolts instead of the stock 3/8". Just some ideas. Don't forget to consider a good cam and what you want to do with the engine and car when you are done. That will make all the difference in the world.
#10
The cam I was planning on using would be at least a 292, I am using this as a daily driver with some nuts. I will be machining out the cooling holes in the 350 heads to match the 403 set, its like 4 holes so no biggie. Also I will tab the head bolts out to 1/2 instead of 3/8 especially since my C ratio is looking around 10:1. As far as parts and labor its no problem, i have a good engine builder I met while in the Marines and he said this should be no problem.
#11
My driving habits are not bad, this Cutlass is probly not gonna see to much racing. But if some teenage punk needs some act right, I need this car to be able to blow their doors off. LOL
#12
I did some research into building a 403. I read that they were notrious for overheating. You will want to drill out the 350 heads to match the coolant passages for the 403 deck. I have also heard that it is a good idea to tap the head bolts out for 1/2" ARP head bolts instead of the stock 3/8". Just some ideas. Don't forget to consider a good cam and what you want to do with the engine and car when you are done. That will make all the difference in the world.
#15
You should be talking to him, instead of posting on a message board.
I am familiar with that mentality. Simple problem = simple solution: Nitrous oxide.
First, find out what it actually needs. Your engine builder can help you with the teardown/inspection.
If you have 403 heads, use them.
At this power level, Olds rods are more than adequate.
Keep the CR below 8.5:1, as N²O works best in "smog" engines. Your engine builder can help you decide which pistons to use.
The existing valves in your 403 heads will do the job.
Use whatever springs/retainers come with your cam kit. Unless the pushrods are actually worn, there is no reason to replace them.
Your engine builder can help you choose the best cam for your application.
403 manifold can handle it. The Performer is a few lbs lighter.
If you already have a Q-jet, it will work as well, if not better. If it does not already have an electric choke, you can add one to it.
If you use a Holley, vacuum secondaries are best for the street.
Already covered.
Transgo P/N 350-1 is a good alternative.
Choice of rear gears (like cams) are an individual choice based on many factors. Biggest is the size of the rear tires that will be used.
Limited slip is a good idea.
Norm
1. 403 block bored .030
2. 403 crank ground down .010
2. 403 crank ground down .010
3. 350 heads from a 72 Cutlass
4. stock 403 rods
5. deck the heads .030 over for a 10.1 c ratio
7. 2.072" valves from a W30
9. Crane lifter, pushrods and springs
Your engine builder can help you choose the best cam for your application.
10. Edlebrock Performer ........
11. Holley 750 electric choke
If you use a Holley, vacuum secondaries are best for the street.
12. Msd distributor and external coil pack
13. ........ B&M Shift kit
14. 3.08 ........
Limited slip is a good idea.
Norm
#16
I stand corrected on the head bolt size. I knew there was something to it, I just wasn't sure of the numbers.
Make sure your coolant system is in good shape. Everything I have read indicates that 403s like to overheat if you let the radiator get in sorry shape.
Make sure your coolant system is in good shape. Everything I have read indicates that 403s like to overheat if you let the radiator get in sorry shape.
#17
Agreed, particularly since the 403 already has beefier rods than other SBO motors.
I concur again. This is all about building cylinder pressure, and low CR with more nitrous is probably the way to build more power. In any case, be sure to use top-quality head gaskets.
Here I'll dissent. While the 2.000 intakes may be adequate, the 1.500 exhaust valves could use use an upgrade. At that point you MIGHTASWELL also have the intakes enlarged.
Keep the CR below 8.5:1, as N²O works best in "smog" engines. Your engine builder can help you decide which pistons to use.
The existing valves in your 403 heads will do the job.
#18
As part of a head job, they could. However, we do not know whether the heads even need to come off. From what we do know, that cash would be better spent on relieving the balance of the exhaust system.
Always beware of the "mightaswell". It can get very expensive, very quickly.
Norm
Always beware of the "mightaswell". It can get very expensive, very quickly.
Norm
#19
#20
I have a 403 I pulled from a 79' Trans Am, and I'm not sure if its concidered to be a Small or Big block. I have a 455 and for the most part they look reletivly the same. Anyway this 403 is going in a 1972 Olds Cutlass now and I want a good engine recipe for it. The objective is to Turbo Charge this engine and also add the 442 hood and utilize the air damns. If you have any answers or ideas plz lemme know thanx for your time.
#21
For info on the 403 check out ofe403
and for a performance build by the olds performance guru Joe Mondello, Olds 403 UnsungHero
Tim
and for a performance build by the olds performance guru Joe Mondello, Olds 403 UnsungHero
Tim
#22
Sounds like you have not checked out the solid main web version.
Not the most reliable of sources.
Also, not the most reliable of sources.
Norm
For info on the 403 check out ofe403 ........
........ Olds 403 UnsungHero
Also, not the most reliable of sources.
Norm
#23
OK, I read it.
Looks like some random opinions were "cut" from a discussion board, and "pasted" onto that page.
Does the author have his 403 Olds confused with a 400 Chev?
Norm
Looks like some random opinions were "cut" from a discussion board, and "pasted" onto that page.
Originally Posted by http://www.442.com/oldsfaq/ofe403.htm
........ The stock 403 heads have 4 additional coolant holes drilled for additional cooling (because of the siamesed bores), compared to 350 heads ........
Norm
#24
#27
No.
Flames/insults/name calling, are counterproductive. They are also indications that the poster is a BS artist.
Norm
#28
Well Norm, don't be too insulted by wagonmaster's comments, I don't think he meant to flame or insult you, just his way of saying "I disagree". But then again, I am not him and should let him speak for himself I guess.
At any rate, I can attest to the fact that many, many, many people at Oldsmobile sites on the web, not only our site; do not have such a high opinion of Mr. Mondello as many people think at first thought. I have not decide for myself yet as I haven't had an opportunity to deal with his company or him personally. I said this just to show that there is quite a bit of disagreement about him and his company so it shouldn't be too surprising to see it here.
At any rate, I can attest to the fact that many, many, many people at Oldsmobile sites on the web, not only our site; do not have such a high opinion of Mr. Mondello as many people think at first thought. I have not decide for myself yet as I haven't had an opportunity to deal with his company or him personally. I said this just to show that there is quite a bit of disagreement about him and his company so it shouldn't be too surprising to see it here.
#29
The main problem seems to be that the company and Joe aren't really together anymore, yet it still runs off of Joe's reputation. Joe is a great guy, IMO. Yes, wrong about the SMW 403, like I said, none of us is perfect, yet he has done a LOT for the Oldsmobile nation. However, deal with Lynn at Mondollar at your own risk....
#32
It really is. I saw some Mondello had underdrive pulleys that you can get on E-bay for like 1/3 the price. Lots of re-boxing. My engine builder went to the PRI show last weekend and spoke to Joe at length about flow benches. Mike said you could not meet a nicer guy, gave him his #, said to call if he needed help with anything. He runs a tech school in Tn now.
#33
........ just his way of saying "I disagree" ........
........ people at Oldsmobile sites on the web, not only our site; do not have such a high opinion of Mr. Mondello ........
I have nothing but respect for Joe. He saw the problems the boat guys were having with 455 bottom ends, came up with an answer, then used it to build a thriving business.
I talked to him numerous times before he moved from So Cal, and a few times afterward. He is personable, knowledgeable, and honest.
Norm
#35
Unfortunately, another sad story regarding Mondello;
http://72.22.90.30/phpBB2/viewtopic.php?t=42707
http://72.22.90.30/phpBB2/viewtopic.php?t=42707
#37
Here is an interesting build on an Olds 403. I know the car magazines are sometimes cheesey but it looks neat.
http://www.popularhotrodding.com/eng...ine/index.html
http://www.popularhotrodding.com/eng...ine/index.html
#39
You too, can have a 403 with these HP numbers. All you have to do, is buy these parts and bolt them together.
No more substance than the one http://www.mondellotwister.com/ArtUnsungH.htm that was posted earlier.
Norm
#40
Yeah, I don't genearlly read the car magazines because I get tired of the same old same old. You can only do so many small block shoot outs, and big block junkyard builds before it gets tiresome. Of course, with SBC and SBF engines bolt on performance is a dime a dozen. I guess they figure you can do it with Olds engines to. LoL