Pontiac GTO Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
59 Posts
Discussion Starter #1
I just dyno’d my engine today. It’s a 490 CI stroker, 10:1 compression, KRE D-port heads out of the box, edelbrock performer intake with a mild hydraulic Roller cam, 850 vac secondary carb MSD Billet distributor, and Ram air exhaust manifolds. It made 616 HP and 703 ft/lb of torque on pump gas. I was very happy. I was hoping for 550 HP so this was great. The monster torque numbers were really a bonus. This will def make driving my big heavy 70 GTO a lot of fun! Thanks for all the help you guys have provided me over the last year while I assembled this motor, my first build.

Mike
 

·
Premium Member
Joined
·
153 Posts
I just dyno’d my engine today. It’s a 490 CI stroker, 10:1 compression, KRE D-port heads out of the box, edelbrock performer intake with a mild hydraulic Roller cam, 850 vac secondary carb MSD Billet distributor, and Ram air exhaust manifolds. It made 616 HP and 703 ft/lb of torque on pump gas. I was very happy. I was hoping for 550 HP so this was great. The monster torque numbers were really a bonus. This will def make driving my big heavy 70 GTO a lot of fun! Thanks for all the help you guys have provided me over the last year while I assembled this motor, my first build.

Mike
Sound like a blast. Hope you upgraded the brakes LOL. post some pictures.
 

·
Premium Member
Joined
·
679 Posts
I just dyno’d my engine today. It’s a 490 CI stroker, 10:1 compression, KRE D-port heads out of the box, edelbrock performer intake with a mild hydraulic Roller cam, 850 vac secondary carb MSD Billet distributor, and Ram air exhaust manifolds. It made 616 HP and 703 ft/lb of torque on pump gas. I was very happy. I was hoping for 550 HP so this was great. The monster torque numbers were really a bonus. This will def make driving my big heavy 70 GTO a lot of fun! Thanks for all the help you guys have provided me over the last year while I assembled this motor, my first build.

Mike
Mike - Did you build the motor? What stroker kit did you use? Congratulations !
 

·
Registered
Joined
·
59 Posts
Discussion Starter #4
Yes I assembled it. The package was put together by the guys at Kauffman Racing Equipment. They supplied the block and everything. I can’t recall the exact specs of the stroker kit and my paperwork is at my shop. Pretty sure the crank was made by eagle. I told them I wanted a very streetable combo, one that would work with the factory AC on my car, but I wanted min 550 HP. This was the setup they sold me. I did it this way because I wanted to be able to build an engine with my son as a project for us to do. We did it all— file-fit the rings,
Plastiguaged all the clearances, degreed the cam, etc, etc. I’ve spent my whole life working on cars but I never built an engine before. Some skills are applicable to any engine and some things are only unique to Pontiacs so it was a steep learning curve but the guys in this forum were def a big help.

Mike
 

·
Registered
Joined
·
3,931 Posts
you dont even have an idea what kind of fun you will have with that torque on hand. , agree about brakes and power steering....sure if your building with quality meterials that you will do it up right....ENJOY!!! thats what its all about
 

·
Registered
Joined
·
59 Posts
Discussion Starter #6
Here's the info on the build:

Ohio Crank forged 4.50/3.00
KB Pistons 943-30 4.5 stroke
Eagle Rods 6.700
KRE Heads 85 cc stock heads
MSD Dist. 8528
RPM Performer intake
Comp cam 235/241HR14+4
Trend pushrods 8.800
 

Attachments

·
Registered
Joined
·
352 Posts
Very nice! Great numbers with that combo!

I’m putting together a 461 stroker for a customer with similar specs. 4 bolt main 400 block, Butler billet main caps, butler 461 forged stroker kit with eagle rods, eagle crank, butler/ross flat top pistons. Top end will be KRE D ports with a port matched northwinds single plane and holley super sniper. We were going to go with a fairly large tight lash solid roller cam but the power you made with a mild roller cam is amazing. The customer’s goal is 650hp at the crank. Street driven as well as track runs around once a month. Car is a ‘77 trans am.

Again very impressed with the power on your setup! Great job
 

·
Registered
Joined
·
3,788 Posts
Here's the info on the build:

Ohio Crank forged 4.50/3.00
KB Pistons 943-30 4.5 stroke
Eagle Rods 6.700
KRE Heads 85 cc stock heads
MSD Dist. 8528
RPM Performer intake
Comp cam 235/241HR14+4
Trend pushrods 8.800

At what RPM's did the engine hit those numbers? Curious as to the RPM you had to spin a 4.5" stroker crank. I want to build a big inch engine at some point in my life as well and on paper I can see 5,800 RPM being a pretty good number to shoot for and not run on the ragged edge. :thumbsup:
 

·
Registered
Joined
·
59 Posts
Discussion Starter #9
Peek HP was at 5,400 RPM, peek torque was at 3,600. One question I had was about the oil pressure. It was recorded by the Dyno throughout the run. It started at 60 psi at 3,500 RPM (the lowest RPM the Dyno recorded data) on one run it went down to 42 psi and on the other it went dwin to 32 psi at 5,800 rpm. Is this a reasonable pressure for a Pontiac engine? This is my first Pontiac build. Thanks for your input.

Mike
 

·
Registered
Joined
·
3,788 Posts
Peek HP was at 5,400 RPM, peek torque was at 3,600. One question I had was about the oil pressure. It was recorded by the Dyno throughout the run. It started at 60 psi at 3,500 RPM (the lowest RPM the Dyno recorded data) on one run it went down to 42 psi and on the other it went dwin to 32 psi at 5,800 rpm. Is this a reasonable pressure for a Pontiac engine? This is my first Pontiac build. Thanks for your input.

Mike


Thanks, better (lower RPM's) than I thought for those kinds of numers.

I personally would be concerned with your oil pressure numbers. Pontiac engines should have 60 PSI above 2500 RPM's. Dropping pressure as RPM's go up is not what you want.

I would discuss this with your dyno man to make sure it was not an equipment fluke. If it is not, then I would be looking for a cause. The rule of thumb is 10 PSI for each 1,000 RPM.

Read this article: https://www.pontiacdiy.com/pontiac-v-8-oiling-system-guide/

There could be a number of reasons. I am going to just ramble on and throw out ideas to consider. :thumbsup:

1st, poor quality oil filter not flowing enough. Butler Pontiac recommends a Wix oil filter.

What oil pump did you use? I used a Mellings 60 PSI pump on a 400 build and had problems. On my present 455 build, I began with a Mellings 60PSI pump. It has a courser quality screen ( larger holes) than the fine screen mesh on the 400 build I did. I feel the fine mesh may have contributed to my problem. Anyway, I then purchased the heavy duty oil pump plate. This is thicker and is designed to provide anticavitation. You can see it and read the description here: https://www.tinindianperformance.com/product/sd-pontiac-oil-pump-plate/ At the time, Butler Pontiac had a Pro-pump they offered, but only for an 80PSI oil pump. They eventually did put out a Pro-pump for the 60PSI oil pump -so I bought this and will use it on my 455.

What oil pan? If you used a deeper pan, did you get the matching pump pick-up tube/screen? You would have also wanted to check the clearance between the bottom of the pan and bottom of the pick-up screen. Too much space can be a problem as well as sitting too low and not enough space.

Windage tray or screen?

Was the pick-up tube secured in any way to the oil pmp so it could not fall off? If the pick-up tube/screen were to fall off, oil pressure can suffer.

I assume you purchased a new oil pump drive shaft? Never use the factory one. You want an aftermarket hardened pump shaft. The factory piece can break. You can get a simple inexpensive one from most any Pontiac parts supplier or step up and get something more rugged. I went with this one from Nitemare Performance: Standard sleeved & hardened oil pump driveshaft Bear GFR used one and as I recall, you have to check your clearances on that larger end sleeve. He has others as well as the oil pumps & oil pump plates.

That said, I would talk with your dyno guy first. I assume the engine is still out of the car? It would be easier now to pull the pan IF needed than once you get it in the car and could have to take it back out.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #11
Thanks for your post. All of the items you listed I addressed during the build. It is a 60 psi Melling pump with a Moroso 7qt pan. I brazed the pickup to the pump housing and I disassembled the pump spring first to prevent damaging it. I test fit the pan to the engine with modeling clay to check and adjust the pickup as recommended by the manufacturer. I have a heavy duty pump shaft. Can’t recall what else you mentioned but I know as I read it that whatever you listed I did. Not sure what else there is to do. Yes the engine is still out. So if needed I can pull the pan but of course I only want to do it if absolutely needed. I will speak to the Dyno guy and the machinist and see what they say.
 

·
Registered
Joined
·
3,788 Posts
Thanks for your post. All of the items you listed I addressed during the build. It is a 60 psi Melling pump with a Moroso 7qt pan. I brazed the pickup to the pump housing and I disassembled the pump spring first to prevent damaging it. I test fit the pan to the engine with modeling clay to check and adjust the pickup as recommended by the manufacturer. I have a heavy duty pump shaft. Can’t recall what else you mentioned but I know as I read it that whatever you listed I did. Not sure what else there is to do. Yes the engine is still out. So if needed I can pull the pan but of course I only want to do it if absolutely needed. I will speak to the Dyno guy and the machinist and see what they say.

OK, sounds like you got it all correct. The only other thing may be oil drain back? Oil is collecting in the top end (maybe heads?) and not draining back fast enough.

I have read that oil whipped around at higher RPM's can be come aerated enough to cause oil pressure changes. But, this seems to be more of an issue when not using a windage tray.

Let us know what turns up. :thumbsup:
 

·
Registered
Joined
·
59 Posts
Discussion Starter #13
That sounds plausible. I did not use a windage tray since it is tough to fit with stroker motors. I spoke to my guy at KRE that provided everything for the build. He said There really isn’t anything else I can do. I asked if I should consider replacing the pan and upgrading to a Canton or maybe changing to a different pump or something but he didn’t think that would be useful. At this point we discussed the fact that I do not plan on Racing this car at the track and it’s going to be limited to me hopping on it every now and then through 1st and second gear. If it blows up then I’ll pull it and rebuild it and if it lasts until I decide to rebuild it in 5-10 yrs then I guess I’ll figure it out the next time around.
 

·
Registered
Joined
·
3,788 Posts
That sounds plausible. I did not use a windage tray since it is tough to fit with stroker motors. I spoke to my guy at KRE that provided everything for the build. He said There really isn’t anything else I can do. I asked if I should consider replacing the pan and upgrading to a Canton or maybe changing to a different pump or something but he didn’t think that would be useful. At this point we discussed the fact that I do not plan on Racing this car at the track and it’s going to be limited to me hopping on it every now and then through 1st and second gear. If it blows up then I’ll pull it and rebuild it and if it lasts until I decide to rebuild it in 5-10 yrs then I guess I’ll figure it out the next time around.

Hate to say this, and I am not the expert builder I would expect KRE to be, BUT........

You have options! First - crank scraper. This will do what it says, scrape excess oil that clings to the crank throws and keep it from being thrown back into the "air" in the engine. It is what I am doing on my engine. I am not planning on using a windage tray, but am going to use a crank scraper.

Second, you can use a deep pan with matching pick-up and run the oil fill 1 qt low to keep the oil level lower and away from the crank throws so they don't whip up and pick up the oil. So the 7 quart pan gets filled with 6 qts. It is my understanding that each inch added to the stock pan (which was done by Royal Pontiac when setting up their engines for the magazine drag tests) added 1 more quart. So deleting 1 quart would mean the oil is 1" lower and away from the crank throws. Milodon also offers a 7 QT pan.

Third, check out the design of this screen. It bolts between the pan & block rails, not on the main caps. I does not state if it would work with a 4.5" stroke, but you might want to inquire. Read the description on the dipstick tube. https://www.cantonracingproducts.com/canton-20-918-windage-tray-pontiac-screen/

Read this article. You can even get a screen or baffle that can be welded deeper inside and to the sides of the oil pan which would also lower it and should work with the longer crank throws.

Again, no expert engine builder like those who do Pontiacs all day long, but geeez, I really don't like the answer you got and I would not be satisfied with "its just the way it is and hopefully you don't lunch your engine if you decide to use its full potential."

Keep digging and find someone who can steer you in the correct direction. :yesnod:
 

·
Registered
Joined
·
3,931 Posts
i would try and get it figured out even if it takes another dyno session since its not installed yet. With the cost of building a Pontiac motor with the quality parts your using i would throw $600 at it rather than another 8K to rebuild it after it eats itself. Once a Pontiac motor is in the car it becomes a job to try and just remove the pan without taking it back out...believe me i know, my first motor did the same thing before it devoured the cam and ran metal through the mains...total loss. I would probably ask the builder to comp the time on Dyno if he put it together and split labor to take the pan off and figure it out. Just my 2 cents its your 8k.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #16
Thanks guys for all the input. After talking to the guys at KRE and the dyno shop (different guys) I think the problem was simply that there wasn't enough oil in the engine. I did use the Moroso 7 qt pan and I set the pickup depth using the modeling clay approach. When I filled it with oil I didn't take into account the filter and only put oil in until the dipstick read full. After the dyno session, the next day when all the engine oil would have long since returned to the pan, the dipstick read a quart low. It held good pressure on the dyno until about 5k rpm and after discussing it with KRE and the dyno shop, the consensus was that the oil was a tad too low and tearing it apart wouldn't be worth it. The bottom line is the money is not as important to me as time. I'm building this engine with my son and he leaves for college in six weeks. It is more important to me to get it running now asap to complete this father-son project and have a little time to enjoy the car this summer and if it grenades in six months I'll deal with it, even though I don't think I'll have a problem when I add more oil. I'll keep ya'll posted on how it turns out.

Mike
 

·
Registered
Joined
·
3,788 Posts
Thanks guys for all the input. After talking to the guys at KRE and the dyno shop (different guys) I think the problem was simply that there wasn't enough oil in the engine. I did use the Moroso 7 qt pan and I set the pickup depth using the modeling clay approach. When I filled it with oil I didn't take into account the filter and only put oil in until the dipstick read full. After the dyno session, the next day when all the engine oil would have long since returned to the pan, the dipstick read a quart low. It held good pressure on the dyno until about 5k rpm and after discussing it with KRE and the dyno shop, the consensus was that the oil was a tad too low and tearing it apart wouldn't be worth it. The bottom line is the money is not as important to me as time. I'm building this engine with my son and he leaves for college in six weeks. It is more important to me to get it running now asap to complete this father-son project and have a little time to enjoy the car this summer and if it grenades in six months I'll deal with it, even though I don't think I'll have a problem when I add more oil. I'll keep ya'll posted on how it turns out.

Mike

Ok, that may be the solution in all this. Understand wanting to get it together for that son/father drive. Keep us posted and pictures coming. :thumbsup:
 
1 - 17 of 17 Posts
Top