351w Top End Overhaul - Advice
08-07-2013, 11:09 PM
#21
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
You eventually get used to your power level, then when you upgrade, it's a beast until you get used to it again. That's why it's good to work your way up, rather than just going huge and not being able to control the power.
I remember when I first got this engine going, felt powerful....now I feel like I should be racing 5 year olds in power wheels.
I remember when I first got this engine going, felt powerful....now I feel like I should be racing 5 year olds in power wheels.
08-08-2013, 08:47 AM
#22
6th Gear Member
Join Date: Aug 2007
Location: Elk Grove, CA
Posts: 5,896
David, having been there/done that, I'd recommend the roller cam too. It's so much less of a PITA in the end that it's worth it, not to mention the performance benefits. I have to use 8qts of Valvoline VR-1 Racing oil every time I change the oil, which adds up quick.
If you are set on going flat-tappet, a set of Rhoads lifters may do you well. I run them on my 331 and love them. They create quite a bit of valvetrain clatter, but if you don't mind that, they're worth it. I jumped from an XE268H to a Magnum 280 w/Rhoads lifters; I expected to lose a little low-end, but actually gained more driveable power at low-rpm's.
If you are set on going flat-tappet, a set of Rhoads lifters may do you well. I run them on my 331 and love them. They create quite a bit of valvetrain clatter, but if you don't mind that, they're worth it. I jumped from an XE268H to a Magnum 280 w/Rhoads lifters; I expected to lose a little low-end, but actually gained more driveable power at low-rpm's.
08-08-2013, 11:24 AM
#23
2nd Gear Member
Join Date: Nov 2010
Location: Ontario
Posts: 493
These threads always turn into building a full out race motor rather than what the poster originally was looking for...Any name brand aluminium head will flow much more air than your stock heads. Even the smallest ones. A trickflow 170 actually is more compareable to other heads in the 180-190cc range due to the way it is designed. Even the edelbrock performer rpms would be a decent increase over stock and with a intake change should easily net you your 40-50hp goal..Your performer intake is not much different than a stock intake..I would go with a performer rpm or an air gap although the air gap is a tight fit under the stock hood...The vic jrs are a decent head and I am running them on my 408..Sure there are bigger and better heads than any of the ones I mentioned..It all depends on how much power you want to make and how much you want to spend.
08-08-2013, 03:06 PM
#25
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
Reliable performance costs money. It's easy to be cheap and throw some parts on an engine, sure. But then you might break other stuff and cost yourself 3x more than what your originally spent. Like the old saying goes, "Cheap, powerful, reliable....pick 2."
When it comes to engine performance, it's easier to waste your own money than it is to spend someone else's. "There's never enough money to do it right, but there's always enough money to do it over."
TFS 170s are way too small for a 351 based engine. Especially if it gets stroked later. That's why TFS makes the FAC 190's, and high port 195's. The Vic Jr's are a good all around head, and run great on 351's.
So you either buy small heads now and if you build more power later, buy another set of heads. Or buy decent heads now, and tame the engine with a smaller cam.
Decent heads now and a smaller cam is probably the OP's best bet, least amount of potential problems, reasonable investment, and he has heads that will support more later if he builds something bigger. And it won't make so much power now that he has to worry about breaking ****. And **** DOES get broken....build a big engine and throw it in a car that was originally intended for 250hp....everything becomes a weak point.
It's always advisable to spend good money on a fuel and oiling system when building ANY kind of performance engine though. Both are reasonably cheap to do, and a problem with either one can destroy an engine in a heartbeat. You can get a kickass oil pan from Canton that's all you'd ever need for anything you could ever do. $250 at Summit for a 6qt baffled street performance pan, and just under $300 will get an 8qt diamond trap door baffled pan (which will handle pretty much anything you could ever do with the car).
A few hundred bucks for the last oil pan you'll ever need is cheap insurance against destroying an engine. As for fuel systems, a mild carb'd street engine can run a decent low cost mech. pump and the factory feed lines and be fine, so no cost there really.
But there's a very good reason to spend extra money on crap that keeps the engine in 1 piece, and you for that matter.
When it comes to engine performance, it's easier to waste your own money than it is to spend someone else's. "There's never enough money to do it right, but there's always enough money to do it over."
TFS 170s are way too small for a 351 based engine. Especially if it gets stroked later. That's why TFS makes the FAC 190's, and high port 195's. The Vic Jr's are a good all around head, and run great on 351's.
So you either buy small heads now and if you build more power later, buy another set of heads. Or buy decent heads now, and tame the engine with a smaller cam.
Decent heads now and a smaller cam is probably the OP's best bet, least amount of potential problems, reasonable investment, and he has heads that will support more later if he builds something bigger. And it won't make so much power now that he has to worry about breaking ****. And **** DOES get broken....build a big engine and throw it in a car that was originally intended for 250hp....everything becomes a weak point.
It's always advisable to spend good money on a fuel and oiling system when building ANY kind of performance engine though. Both are reasonably cheap to do, and a problem with either one can destroy an engine in a heartbeat. You can get a kickass oil pan from Canton that's all you'd ever need for anything you could ever do. $250 at Summit for a 6qt baffled street performance pan, and just under $300 will get an 8qt diamond trap door baffled pan (which will handle pretty much anything you could ever do with the car).
A few hundred bucks for the last oil pan you'll ever need is cheap insurance against destroying an engine. As for fuel systems, a mild carb'd street engine can run a decent low cost mech. pump and the factory feed lines and be fine, so no cost there really.
But there's a very good reason to spend extra money on crap that keeps the engine in 1 piece, and you for that matter.
08-08-2013, 03:58 PM
#26
4th Gear Member
Join Date: Feb 2006
Location: So. Cal,the O.C.
Posts: 1,538
08-08-2013, 10:16 PM
#27
2nd Gear Member
Join Date: Nov 2010
Location: Ontario
Posts: 493
One thing we have overlooked are the details on your current engine..Especially if you want to reuse your shortblock as is...Do you know what year the engine is? Or the cylinder heads? I am curious what pistons you have in the engine as the compression ratio is a very important part of the equation when trying to build an engine...If you are running later model heads (late 70s till late 80s) they have huge combustion chambers that kill compression and performance.
08-09-2013, 02:08 AM
#28
5th Gear Member
Thread Starter
Join Date: Jul 2006
Location: San Diego, CA
Posts: 2,990
I agree that these threads always end up becoming building a full out race motor, but I am totally OK with upping my budget a little bit if it's worth it. Finding that balance between power and practicality is tough but the discussion has helped so far!
With that said, it sounds like a roller cam is the way to go, thanks Tad for weighing in with your experience. $250-$300 more is manageable for the benefits given. I definitely don't want to jump to a custom cam though, an off the shelf cam should suit what I want to do, I just have to find the right one.
As for the details of my engine, it has the original block and heads rebuilt less than 15,000 miles ago. 1969 blocks are good, I've read about that they have the higher nickel content in them which makes them stronger. My heads would be the better heads, but when I had the engine rebuilt one head had two hairline cracks that had to be plugged. They've had their better days so rather than rebuilding the heads again, going with aluminum heads sounds like a route that will be worth it. I'm not sure what pistons are in there since I haven't taken it apart yet, but they should be stock style .04 over pistons that my machine shop put in during the rebuild.
For comp cams hydrolic rollers, it looks like I have a couple options between the Magnum and Xtreme line. Those more aggressive start recommending stall converters and shorter gearing. Which one should work best with my 3.25 gears, headers, and the Victor Jr's, given that the those aren't too big of heads? Will I need to be concerned with clearance?
Cams
Intake
Would the Weiand Stealth intake be a good upgrade from my Performer? I've read it's comparable, if not better, than the Performer RPM and I like the price. Also I don't know if I want my whole engine to look like an Edelbrock ad
Rockers and Pushrods
Should I go for roller tip rockers? They don't seem too expensive. Full roller rockers are out of my price range and I probably won't benefit from them. Do I just get/reuse stock length pushrods?
That should cover everything in the top end... thanks again everyone for your help and advice.
With that said, it sounds like a roller cam is the way to go, thanks Tad for weighing in with your experience. $250-$300 more is manageable for the benefits given. I definitely don't want to jump to a custom cam though, an off the shelf cam should suit what I want to do, I just have to find the right one.
As for the details of my engine, it has the original block and heads rebuilt less than 15,000 miles ago. 1969 blocks are good, I've read about that they have the higher nickel content in them which makes them stronger. My heads would be the better heads, but when I had the engine rebuilt one head had two hairline cracks that had to be plugged. They've had their better days so rather than rebuilding the heads again, going with aluminum heads sounds like a route that will be worth it. I'm not sure what pistons are in there since I haven't taken it apart yet, but they should be stock style .04 over pistons that my machine shop put in during the rebuild.
For comp cams hydrolic rollers, it looks like I have a couple options between the Magnum and Xtreme line. Those more aggressive start recommending stall converters and shorter gearing. Which one should work best with my 3.25 gears, headers, and the Victor Jr's, given that the those aren't too big of heads? Will I need to be concerned with clearance?
Cams
Intake
Would the Weiand Stealth intake be a good upgrade from my Performer? I've read it's comparable, if not better, than the Performer RPM and I like the price. Also I don't know if I want my whole engine to look like an Edelbrock ad
Rockers and Pushrods
Should I go for roller tip rockers? They don't seem too expensive. Full roller rockers are out of my price range and I probably won't benefit from them. Do I just get/reuse stock length pushrods?
That should cover everything in the top end... thanks again everyone for your help and advice.
Last edited by 4reboy; 08-09-2013 at 02:13 AM.
08-09-2013, 04:14 AM
#29
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
I'd go with the 270, the Xtreme series have better lobe profiles. But make sure you get the springs for that cam, or whichever cam you use. A single plane intake would be nice, but you'd probably need a better carb for it as well as more compression than what you'll probably have; so the Stealth or RPM would be fine.
Pushrod length you won't know until it's together, it has to be measured. Roller tip rockers will help with valve guide wear, but full roller rockers are worth the money if you have it. The roller trunion actually reduces temperature in the rockers substantially. You could just go with a basic 1 piece pushrod and a quality roller tip rocker.
And this head gasket:
http://www.summitracing.com/parts/fel-8548pt-2
And this intake gasket:
http://www.summitracing.com/parts/fel-1250s3
Intake gasket might be different depending on what heads you get.
Those gaskets are rugged and work fine with daily drivers. The standard 1250 has a habit of tearing around the cooling ports sometimes, and the 1011 head gaskets that some of the head manufacturers recommend is ****.
Pushrod length you won't know until it's together, it has to be measured. Roller tip rockers will help with valve guide wear, but full roller rockers are worth the money if you have it. The roller trunion actually reduces temperature in the rockers substantially. You could just go with a basic 1 piece pushrod and a quality roller tip rocker.
And this head gasket:
http://www.summitracing.com/parts/fel-8548pt-2
And this intake gasket:
http://www.summitracing.com/parts/fel-1250s3
Intake gasket might be different depending on what heads you get.
Those gaskets are rugged and work fine with daily drivers. The standard 1250 has a habit of tearing around the cooling ports sometimes, and the 1011 head gaskets that some of the head manufacturers recommend is ****.
08-09-2013, 08:36 AM
#30
6th Gear Member
Join Date: Aug 2007
Location: Elk Grove, CA
Posts: 5,896
I've got a Weiand Stealth on my 331 and I like it. I mean, I've never put an RPM on and compared it directly, but my motor makes power all the way up to 6200 where the cam dies off.
I went with the basic Crane Energize aluminum full-roller rockers (7/16" stud) when I built my motor. They're cheap and noisy, but effective. I'd love to have a set of the Comp Cams forged rollers, but that's money I don't have to burn. Lacking the funds for the Energizers, a set of the Comp Cams roller-tip rockers would probably do you well.
Get yourself a proper adjustable pushrod length checker. I really like the one I got from Comp Cams. It has graduations like a micrometer which tell you exactly how long the pushrod is. Proper pushrod length is vital to valvetrain longevity.
I went with the basic Crane Energize aluminum full-roller rockers (7/16" stud) when I built my motor. They're cheap and noisy, but effective. I'd love to have a set of the Comp Cams forged rollers, but that's money I don't have to burn. Lacking the funds for the Energizers, a set of the Comp Cams roller-tip rockers would probably do you well.
Get yourself a proper adjustable pushrod length checker. I really like the one I got from Comp Cams. It has graduations like a micrometer which tell you exactly how long the pushrod is. Proper pushrod length is vital to valvetrain longevity.