[Mad Max]

====

The E Code and the A Code had "solid wall" webbing cast into them (between the cylinders)
..they are the most desirous of all non-race block Duke motors. They were commonly called "Roller Blocks", because of the roller hydraulic lifters that they all had. Also, they were stock in the Postal Van (LLV).

As an aside here:

The hydro lifters are a good thing/bad thing, IMHO.

Bad thing because you are limited to the lift that you can/could use. And they will not follow a "radical" ground camshaft profile, either. Lifter floating raises it's ugly head. But the good is that the cylinder head flow gives up at about 4500 RPM so this is all moot.

Also, the hydro lifters need clean oil and LOTS of it to work well. This is why I always have said that you do not need a fancy oil pump on these engines. Your money is better spent elsewhere. I have read before that an aftermarket, Hi-Pressure oil pump takes 4 to 6 HP to run it. I have no facts to back that up, however...

SE, I started this thread for those individuals that want to build a healthy 2.5. They aren't going to have a serious race machine, but something that will be fun to drive and have a minor amount of bag... AND get some respectable fuel mileage.
You've added some info that I neglected since I'm an onion and forget stuff.
You're tune should have a link here, since it is probably incorporated with this info.
Feel free to add a tag here.
I'm sure readers will appreciate it.
One stop shopping?

 

[edfiero]

Question on Balancing: If I replace the pistons on an engine, keeping the Rods, and Crank, at what point do I need to be concerned about having the engine balanced? If all 4 pistions were within a gram or two of each other, is that OK even if the new pistons were 30 or 40 grams different from the original ones? Or, is the fact that they are different from the original ones cause the need for the rebalance?

Also, if I added a harmonic balancer, does that give me any more room before I have to worry about the balance?

My concern isn't so much the cost of the balance, but I don't know where to take it. No shops of that I know of, and don't know where to get any local references from.

And if you guys tell me I need a balance, what to I give the shop? Do they need the whole engine, or would they need the Crank and Pistons out of the engine?

Thanks

 

[Mad Max]

^^^ Edfiero, GM did not do a great job of balancing the 2.5 engine components. They had a "tolerance" -in other words, if the assembly was within 5 grams it was acceptable.
It is not so much a change of piston type or size, but it is important to try to have all of the pistons weigh exactly the same.
If you spin a crankshaft on a horizontal axis, it inherently wants to slam against the saddles it is riding in because of the 4 crank throws.
The 4 throws (where each connecting rod attaches), or pistons going up and down create some HUGE forces on the crank. If you have a piston that weighs more than the others... even by a few grams, it will exert more force than a lighter one. (common sense) This in turn will inhibit the crank from spinning at high RPMs since one throw will be creating more force casuing an imbalance.
Ok, that is one part of the equation.
The next is the actual connecting rod. If one end of that rod is heavier than another rod, this too will create an imbalance. The rods are set up on a balance assembly (a fixture that has a balance point and a scale that weighs the end) to see if the ends are heavier than each other. So, think of it this way... you are trying to find the center of the rod where it will balance on the end of your finger. Each rod will have a different balance point if an end is heavier. Ideally, you want to have all of the rods have the same balance point. The machinist will remove some weight to acheive this. He will also weigh the rods to find the lightest one, and then try to match the others to that weight.
Next... if you take a harmonic balancer and spin it at a high rate of speed, if it has a heavier area in the circumference, it will try to send the heavier part into space.:haha: Think about balancing a wheel/tire. Same principal. Same with a flex plate/flywheel. Machined parts usually have a heavier point in the outer part of their circumference. A machinist will spin the parts on a machine that is designed to locate a heavy spot with a strobe light. Once this area is located, material is removed to compensate for the heavier spot. The idea is to have parts spin true without any heavy areas.
If you combine all of these rotating parts, a little difference in a piston, rod, crank, harmonic balancer and flywheel can add up really quickly.
So... the ideal situation is to have no imperfections at all. This will increase engine life and performance. Each part should travel through its motions exactly the same.

Balancing parts:
1. Crank
2. Rods
3. Pistons (without rings)
4. Harmonic balancer
5. Flex plate or flywheel
6. If standard shift, the pressure plate.

I know it can be expensive to do this, but the outcome is a better performing engine. You may have to ship the parts to a balancing shop, (I have many times) but I have found it to be worth it.

 

[0Evil1]

I done mean to bring up and old thread but I got some questions. I am going to sound like a newbie... I am. I will openly admit it. farthest I have got into an engine is intake gaskets.. so, yes I am new...

I got a lot of dumb questions and some of you will probably get annoyed with them. so I want to apologize in advance.

Might I ask,
Ignition system?
Distributer?
bore size?
valve specs?

I know I am going to sounds dumb but this is a first every build for me. I figure a build is easier than swapping harnesses/mounts/exhaust

wife doesn't want me to swap engines is the one in it can be rebuilt due to the fact of she wants me to restore it... starting with the drivetrain.

wanted to edit this
I have looked for clevite 77 tri metal bearings and can not find anything for the 151 cubic inch engines.. am I looking in the wrong placed? might I get some part numbers?

what do 'you' recommend for a crank?
rods? I-beam? h-beam? length?
what size pistons will work? 4.000 bore?

 

[Mad Max]

Evil1...
Actually, no questions are really dumb if you don't know the answers...
Better to ask than to fail.

You need to set your priorities. If you want to go racing, this is the wrong engine to use. If you want to have a little fun and a daily driver, you are on the right track.

Since your 2.5 is TBI, this limits your choices for ignition/distributor.
You will need to run the stock unit since it sends a signal to the ECU for cam angle (one part of timing the injection).

The 2.5 bore size stock is 4.00", which is the same as a small block Chevy.
Coincidentally, the piston compression height (wrist pin to piston crown distance) is also the same as Chevy.
These engines were basically half of a 301 Pontiac V8, and also share the same piston size and connecting rods. You can also use the 301 pistons (pic is in second post) but the Chevy units are a better choice since they are less expensive and are hypereutectic castings.

You can spend a lot of money on larger valves, but the return for your $ is going to be minimal. Oldsmobile 350 V8 valves are pretty close to the same stem, length and style, but the actual valve head is larger. They have been installed in the 2.5 head by some racers, but will require a larger valve seat to be installed and some porting work in the bowl under the valve head (de-shrouding work).

Best bet is to have the engine bored to 4.30 and use Chevy pistons.
You can also run a larger cam which will give you more bag.

The biggest issue is the fuel and timing map in the ECU. These are set so lean, it kills power immensely.
Craig Moates - https://www.moates.net/
is the guy who is really good with ECU performance. He can set you up with the hardware/software to tune your rig.
Unfortunately, it is expensive and you need to use a dyno or have someone who is familiar with ECU tuning.
There are chips available, but they are still a compromise for best power.

Hope this helps...

Confucius say: Man have question, need answer. :haha:

 

[BillJ]

I see the $16 cost for the 350 pistons. Of course that was almost a year ago but I don't see pistons offered for anywhere near that price. Where should I look? And thanks for these good helpful threads.

 

[Mad Max]

I see the $16 cost for the 350 pistons. Of course that was almost a year ago but I don't see pistons offered for anywhere near that price. Where should I look? And thanks for these good helpful threads.

Sorry Billj,
I have not kept up with this thread, although I think I've attached URLs to the sites that offer the pistons for low $$.
Once you go into the small block chevy, the prices drop like a brick. Funny part... GM figured they could save $$ by interchange. You simply have to know what works.

 

[S10Gary]

====

The E Code and the A Code had "solid wall" webbing cast into them (between the cylinders)
..they are the most desirous of all non-race block Duke motors. They were commonly called "Roller Blocks", because of the roller hydraulic lifters that they all had. Also, they were stock in the Postal Van (LLV).

As an aside here:

The hydro lifters are a good thing/bad thing, IMHO.

Bad thing because you are limited to the lift that you can/could use. And they will not follow a "radical" ground camshaft profile, either. Lifter floating raises it's ugly head. But the good is that the cylinder head flow gives up at about 4500 RPM so this is all moot.

Also, the hydro lifters need clean oil and LOTS of it to work well. This is why I always have said that you do not need a fancy oil pump on these engines. Your money is better spent elsewhere. I have read before that an aftermarket, Hi-Pressure oil pump takes 4 to 6 HP to run it. I have no facts to back that up, however...

Eddie are you saying that my 1992 VIN code A 2.5 has a roller cam from the factory? Is it also true that it has no timing chain but the cam is gear drive? Is it possible to increase compression to like 9:1, port and polish heads and manifold, and a performance cam and balance all moving parts to gain 50 hp?

 

[Mad Max]

^^ 'A' code engines all have roller cams, timing gears and no chain.
It is possible to gain HP with these mods, 50 HP is being optimistic. You will also need a header or at least a better exhaust system.

One BIG issue... you have to "Tune" your TBI for these performance changes to the engine internals. The TBI system already runs very lean as is. You can have all the cam you may dream of, plenty of compression, but without more fuel and air intake, you won't see diddly...

 

[mattlance13]

^^ 'A' code engines all have roller cams, timing gears and no chain.
It is possible to gain HP with these mods, 50 HP is being optimistic. You will also need a header or at least a better exhaust system.

One BIG issue... you have to "Tune" your TBI for these performance changes to the engine internals. The TBI system already runs very lean as is. You can have all the cam you may dream of, plenty of compression, but without more fuel and air intake, you won't see diddly...

is it possible to add the "A" code roller cam to the "e" code engine? my A code head is cracked, and i just picked up an E code truck(93k on odometer) and want to rebuild the motor and use it as a DD/gas saver. id like the best of the best if im gonna be dropping money into a 2.5. id really like to hit 30 or higher mpg. im familiar with eddys tune as well.

 

[Mad Max]

Dukes all have roller cams from '86 and newer.
If you are going to invest in one of these gems... I suggest buying a new mileage cam.
Give the guys at Oregon Cam grinders a call. They are reasonably priced and answer your questions without attitude.


To answer your question: Yes an 'A' code cam will drop right into an 'E' code engine. The specs are only slightly different.
IIRC; the 'A' code cam has slightly higher lift.

 

[Mad Max]

Wow, it's been a while since I saw any action on this thread.
A while back, I built an '82 2.5 out of a Jeep. It has the early block with the Chevy bell housing bolt pattern. I am running an '88 Ford Turbo T5 Borg warner behind it, all a 'bolt in' to one of my S10s.
I had the block bored to .030, running Chevy 350 hypereutectic flat top pistons with valve reliefs, and early Chevy 327 small journal 6" rods (not the stock 5.7"). The rods are the same big end size (2.0") as the 2.5, but the 327 big end is wider than the 2.5 rod. I had a machine shop narrow the big ends to the same size as the 2.5 rod.
This mod brings compression up to about 10.0 to 1 or thereabouts. I haven't calculated it yet. It's pretty much like stroking the engine.
So... someone will ask if the piston sticks out above the deck... Actually, there is still plenty of room from piston top to the deck surface!
I had the rotating assembly balanced (as usual) but the Jeep flywheel is super heavy (35 lbs.). I had 10 lbs. cut off of it.

I am running a high volume oil pump with a new pick up screen.

Next, I installed a BIG flat tappet cam. .510" lift and 292* advertised duration with a .110* split on the lobes. An aluminum cam gear from a 250 Chevy 6 cylinder works perfectly.
I bought a set of Chevy Big Block rocker roller arms (Crane gold units - used) the roller rockers have a ratio of 1.70 to 1 whereas the stock rockers are 1.73 to 1. Since I have a rather large cam, the loss of ratio will be insignificant. I am running the roller rockers, so I had to buy longer push rods to even out the valve train geometry. IIRC, they are .3 longer. They came from Comp Cams in Memphis, TN.
For the cam driven ignition, I found a super rare MSD distributor run by an MSD control box.

For the head: I used the stock '82 head but replaced the intakes with Oldsmobile 350 valves. They are 1.70 VS the stock 1.50 valves and are a direct bolt in. I unshrouded the area around the edge of the valve (closest to the edge of valve where the head bore edge is), blended the bowl and shaped the valve guides to flow better. Gasket matched the ports and added Chevy small block Z-28 valve springs with Chevy retainers and keepers. I left the exhaust valves stock size since I didn't think there would be much improvement with bigger valves. Installed bronze valve guide inserts and ended with a 3 angle valve job.

I also found an early Offenhauser "Dual Port" 4 barrel intake manifold and am using a 2" carb spacer to increase velocity. The carb is a Holley 390 CFM 4 barrel.

The exhaust is a modified stock header opened to 2 1/2". Behind that is a 2 1/2" high flow cat exiting into a 3" exhaust system
I will run a 160* Tstat, and gaskets are all high end FelPro.

What's it all worth? Since the shop has a dyno, I guess I will find out.
I figure that this will produce close to 150 crank HPs, but the rear wheel HP will be closer to 120 HP.
I haven't been home in over a year, the engine is sitting on a stand. Some day - when I am not out on assignment, this will all go into my '92 Blue S10.
I hope soon.

 

[jazziejeff5]

Here is a list of some parts and improvements that would make a noticeable difference for a Duke rebuild:
Start at the bottom...
1. Clevite 77 tri metal bearings
2. Balanced reciprocating assembly (important!)
3. High volume oil pump (some will argue this, but it has worked for me every time)
4. High end FelPro gasket set. Has the silicone blue oil pan gasket.
5. Chevy 350 flat top pistons. They have the same compression height as the stock dish 2.5 piston (pin to piston crown distance) and the same size piston pin too. You can buy a hypereutectic 350 piston for $16!!! Compression will increase from 8.5 to a little over 9:1.
6. Moly piston rings. Better than the iron ductile units.
7. Match port the head to gaskets. The heads on these engines are pretty close, but the benefit is there still...
8. Porting the intake/ exhaust runners. This can be tricky, you can actually lose HPs. If you knock off the valve guide sharp edges and blend the guide in the bowl, this usually helps flow and doesn't mess up the runners.
9. Cam. Oregon Cam grinders have several different grinds for this engine. They are great... you can actually talk to these guys and tell them what your requirements are, they will provide you with the right cam for your application.
10. Aluminum timing gear. This replaces the phenolic gear and doesn't shred. They are slightly noisier than the stock gear, but the long life is by far a better choice
11. Roller rockers. IIRC, Chevy big block rockers are a bolt on. There are different ratios, the Oregon boys are the best for recommending ratio choice/ cam combination.
12. Stock header... This is an easy one. Cut the stock header flange off,
(it's 1 1/2" in diameter) and weld on a 2 1/2" flange. This will effectively give you a performance header for cheap.
13. 2 1/2" exhaust - a muff shop can bend up a head pipe to cat for a 2 1/2" pipe.
14. High flow 2 1/2" cat. This connects right to the pipe from the header.
15. Performance exhaust: http://www.summitracing.com/parts/sum-680031
16. If you are really going for it... a performance chip for the ECU.

These inprovements can give you an honest 120 HPs. Not much of a gain, but it makes an S10 Duke fun to drive.

Figure about $1,500 to $1,800 for everything - if you do most of the work yourself. It can be done for less if you shop around and don't go for all of the upgrades.

Wow, it's been a while since I saw any action on this thread.
A while back, I built an '82 2.5 out of a Jeep. It has the early block with the Chevy bell housing bolt pattern. I am running an '88 Ford Turbo T5 Borg warner behind it, all a 'bolt in' to one of my S10s.
I had the block bored to .030, running Chevy 350 hypereutectic flat top pistons with valve reliefs, and early Chevy 327 small journal 6" rods (not the stock 5.7"). The rods are the same big end size (2.0") as the 2.5, but the 327 big end is wider than the 2.5 rod. I had a machine shop narrow the big ends to the same size as the 2.5 rod.
This mod brings compression up to about 10.0 to 1 or thereabouts. I haven't calculated it yet. It's pretty much like stroking the engine.
So... someone will ask if the piston sticks out above the deck... Actually, there is still plenty of room from piston top to the deck surface!
I had the rotating assembly balanced (as usual) but the Jeep flywheel is super heavy (35 lbs.). I had 10 lbs. cut off of it.

I am running a high volume oil pump with a new pick up screen.

Next, I installed a BIG flat tappet cam. .510" lift and 292* advertised duration with a .110* split on the lobes. An aluminum cam gear from a 250 Chevy 6 cylinder works perfectly.
I bought a set of Chevy Big Block rocker roller arms (Crane gold units - used) the roller rockers have a ratio of 1.70 to 1 whereas the stock rockers are 1.73 to 1. Since I have a rather large cam, the loss of ratio will be insignificant. I am running the roller rockers, so I had to buy longer push rods to even out the valve train geometry. IIRC, they are .3 longer. They came from Comp Cams in Memphis, TN.
For the cam driven ignition, I found a super rare MSD distributor run by an MSD control box.

For the head: I used the stock '82 head but replaced the intakes with Oldsmobile 350 valves. They are 1.70 VS the stock 1.50 valves and are a direct bolt in. I unshrouded the area around the edge of the valve (closest to the edge of valve where the head bore edge is), blended the bowl and shaped the valve guides to flow better. Gasket matched the ports and added Chevy small block Z-28 valve springs with Chevy retainers and keepers. I left the exhaust valves stock size since I didn't think there would be much improvement with bigger valves. Installed bronze valve guide inserts and ended with a 3 angle valve job.

I also found an early Offenhauser "Dual Port" 4 barrel intake manifold and am using a 2" carb spacer to increase velocity. The carb is a Holley 390 CFM 4 barrel.

The exhaust is a modified stock header opened to 2 1/2". Behind that is a 2 1/2" high flow cat exiting into a 3" exhaust system
I will run a 160* Tstat, and gaskets are all high end FelPro.

What's it all worth? Since the shop has a dyno, I guess I will find out.
I figure that this will produce close to 150 crank HPs, but the rear wheel HP will be closer to 120 HP.
I haven't been home in over a year, the engine is sitting on a stand. Some day - when I am not out on assignment, this will all go into my '92 Blue S10.
I hope soon.

yes it's been a while since I've been here. I keep getting locked out. Yes my 91 is a roller cam but I can run hydrolic cam from Comp cams but u have measure for new pushrods. My cam was ground special for me by Camcraft in Arden NC. For 200.00 best price I found anywhere. I found the same intake ur taking about but new but he wanted to much. Our engines are pretty much the same. I would love to know what urs dyno was I appreciate you letting me know

 

[jazziejeff5]

^^^ Edfiero, GM did not do a great job of balancing the 2.5 engine components. They had a "tolerance" -in other words, if the assembly was within 5 grams it was acceptable.
It is not so much a change of piston type or size, but it is important to try to have all of the pistons weigh exactly the same.
If you spin a crankshaft on a horizontal axis, it inherently wants to slam against the saddles it is riding in because of the 4 crank throws.
The 4 throws (where each connecting rod attaches), or pistons going up and down create some HUGE forces on the crank. If you have a piston that weighs more than the others... even by a few grams, it will exert more force than a lighter one. (common sense) This in turn will inhibit the crank from spinning at high RPMs since one throw will be creating more force casuing an imbalance.
Ok, that is one part of the equation.
The next is the actual connecting rod. If one end of that rod is heavier than another rod, this too will create an imbalance. The rods are set up on a balance assembly (a fixture that has a balance point and a scale that weighs the end) to see if the ends are heavier than each other. So, think of it this way... you are trying to find the center of the rod where it will balance on the end of your finger. Each rod will have a different balance point if an end is heavier. Ideally, you want to have all of the rods have the same balance point. The machinist will remove some weight to acheive this. He will also weigh the rods to find the lightest one, and then try to match the others to that weight.
Next... if you take a harmonic balancer and spin it at a high rate of speed, if it has a heavier area in the circumference, it will try to send the heavier part into space.:haha: Think about balancing a wheel/tire. Same principal. Same with a flex plate/flywheel. Machined parts usually have a heavier point in the outer part of their circumference. A machinist will spin the parts on a machine that is designed to locate a heavy spot with a strobe light. Once this area is located, material is removed to compensate for the heavier spot. The idea is to have parts spin true without any heavy areas.
If you combine all of these rotating parts, a little difference in a piston, rod, crank, harmonic balancer and flywheel can add up really quickly.
So... the ideal situation is to have no imperfections at all. This will increase engine life and performance. Each part should travel through its motions exactly the same.

Balancing parts:
1. Crank
2. Rods
3. Pistons (without rings)
4. Harmonic balancer
5. Flex plate or flywheel
6. If standard shift, the pressure plate.

I know it can be expensive to do this, but the outcome is a better performing engine. You may have to ship the parts to a balancing shop, (I have many times) but I have found it to be worth it.

Oh yes I'm running 1:8 ratio rockers here's a picture of some parts my buddy has for sale and yes that's a overhead cam kit!!

 

[jazziejeff5]

Oh yes I'm running 1:8 ratio rockers here's a picture of some parts my buddy has for sale and yes that's a overhead cam kit!! View attachment 336212 View attachment 336213 View attachment 336214

But u can get the newer crank with the crank trigger gear. The crank has the gear on it but I don't believe they ever actually started using a crank triggered sensor

 

[Mad Max]

I used the crank with the gear on it. Supposedly... it is stronger than the older cranks.
Nice header BTW. Jeep 2.5 with mods? Fiero?
I had all of the Super Duty stuff like your friend, but sold it all.
I also had the Holley intake and throttle body for the 86 Duke. Sold that too.
The cam kit looks like a 2.0 OHC adapted to a 2.5. Yes?

Nice looking lump of iron you have there...
You do know that a 2.5 is a lump... Ha

 

[jazziejeff5]

Eddie are you saying that my 1992 VIN code A 2.5 has a roller cam from the factory? Is it also true that it has no timing chain but the cam is gear drive? Is it possible to increase compression to like 9:1, port and polish heads and manifold, and a performance cam and balance all moving parts to gain 50 hp?
[/QUOTE

I used the crank with the gear on it. Supposedly... it is stronger than the older cranks.
Nice header BTW. Jeep 2.5 with mods? Fiero?
I had all of the Super Duty stuff like your friend, but sold it all.
I also had the Holley intake and throttle body for the 86 Duke. Sold that too.
The cam kit looks like a 2.0 OHC adapted to a 2.5. Yes?

Nice looking lump of iron you have there...
You do know that a 2.5 is a lump... Ha

Hello. I’m new here and still lost when comes trends responding etc and this may be way old. Anyway I. Built my 91 E code with 350 flat top pistons there like 15.00 each had the deck cleaned up cut like .020 off and .040 off the head modified the tbi intake to run a Holley 500cfm 2bbl and yes it came a roller and I wanted to keep it a roller. I found a place in Ashville NC. Called Camcraft ! 827-681-5183 he is very knowledgeable and knows a lot about the 151. He custom ground my cam for 200.00 and I’m building a new one that he’s grinding a cam for right now. Anyway I got a header for a 85 Jeep 2.5 and had the out side tubes fixed by local racer. I’m also running BBC 1.8 roller rockers and I set rocker geometry and pushrod length. It runs really good a lot of torque with stock automatic transmission it runs 11:25s in 1/8th mile

I used the crank with the gear on it. Supposedly... it is stronger than the older cranks.
Nice header BTW. Jeep 2.5 with mods? Fiero?
I had all of the Super Duty stuff like your friend, but sold it all.
I also had the Holley intake and throttle body for the 86 Duke. Sold that too.
The cam kit looks like a 2.0 OHC adapted to a 2.5. Yes?

Nice looking lump of iron you have there...
You do know that a 2.5 is a lump... Ha

hey I’m sorry it takes me so long to respond I thought I had my settings to where I would get notification. But yes it’s a Jeep header and I have a that’s big drag racer and builder cut the outer tubes for me I did that because I didn’t know if the header I found would work on my truck and didn’t wanna pay fortune to have one made. But since then I’ve found a couple that will work. The chrome one is the one I bought and had cut and the other one is for a 80s Isusu trooper. They will if clearance is good

 

[jazziejeff5]

I used the crank with the gear on it. Supposedly... it is stronger than the older cranks.
Nice header BTW. Jeep 2.5 with mods? Fiero?
I had all of the Super Duty stuff like your friend, but sold it all.
I also had the Holley intake and throttle body for the 86 Duke. Sold that too.
The cam kit looks like a 2.0 OHC adapted to a 2.5. Yes?

Nice looking lump of iron you have there...
You do know that a 2.5 is a lump... Ha

Thanks. And yes ur right that a lump of iorn lol. Please let me know what your motor does on the dyno. Ours are very similar and that give me an idea what hp mine is thanks

 

[jazziejeff5]

SE, I started this thread for those individuals that want to build a healthy 2.5. They aren't going to have a serious race machine, but something that will be fun to drive and have a minor amount of bag... AND get some respectable fuel mileage.
You've added some info that I neglected since I'm an onion and forget stuff.
You're tune should have a link here, since it is probably incorporated with this info.
Feel free to add a tag here.
I'm sure readers will appreciate it.
One stop shopping?

Hey. Yes u are right, stock oil pump is plenty just do a lot oil drain hold grinding to open them up and yes the high volume etc pumps pull like 5hp when me and my brothers raced limited stock and put much into our motors we cleaned up and opened up all oil return holes and blocked off in wanted hole and ran stock oil pump

 

[jazziejeff5]

Thanks. And yes ur right that a lump of iorn lol. Please let me know what your motor does on the dyno. Ours are very similar and that give me an idea what hp mine is thanks

Oh yes I forgot to say That my cam now is 469 lift and with the 1.8 rockers I’m at 482 with roller cam my new one I’m having ground will put me right at 500 lift with my rocker arms and that’s about all u want unless you are getting really serious.