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TBART70
10-17-2016, 04:39 PM
This is going to be long.

Hello everybody, I have a 548 CI BBC, New Gen 5 Bowtie block, 4.600 bore, 4.125 stroke. I was with the engine builder every step of building this thing. It has a Straub Technologies custom Hydraulic Roller cam with Morel hydraulic lifters. On the dyno with a small intake and 850 carb it made 690 hp and 750 ft. lbs. torque.

It has been in the car for a year, but I have been chasing problems the whole time. On the dyno we had good oil pressure, 35 psi hot at idle, 65 at 6200 rpm. When I put it in the car it had 10 psi at hot idle and only 50psi at 6000 rpm. The Morel lifters were also very noisy. I pulled the engine and switched out the Billet Moroso pump for a Titan gerotor pump. When I put it back together I had 35 at hot idle and 70 at 6000. The lifters were still noisy and one collapsed. I put in a new set of Morels and still had a noisy valve train. About 2 months ago I took engine builder for a ride, he felt it was down on power, he asked me many times if I felt like it had 750 ft. lbs. I never answered him( it seemed low ). He also was not happy about the valve train noise, I had a feeling that it was on the verge of another collapsed lifter. He said park it until we could figure something out. I pulled it apart and put in a set of Crower solids, when I primed the motor the lifters seemed to have a lot of oil coming from the bottom of them, put it back together and fired it up. It sounded meaner and had more power. I did not drive that much, but the solids were quieter than the hydraulics. I don't know how much more power it could be making but the Holley EFI needs more time on the solids to learn. Problem is my oil pressure is down to 15 psi hot with the solids. They are a HIPPO type. I pulled it apart again and put in a set of Morel solid in number one cylinder because I thought it might be lifter bore clearance. Primed it again and had the same gush of oil. I looked with my scope and could see it was from the HIPPO not the lifter bore. I had an old set of non HIPPO and put it in #1 and there was much less oil flow. If I put in the whole set of old style non HIPPO, I bet my oil pressure would be fine. The issue is that I should be able to run the Hydraulics with no issue, but...... My bearing clearnce on the mains is .0024, rods were same. According to Straubs engine builder at Foxwell Motorsports, he feels that I have had an oiling problem since day 1. They use the Morel Hydraulics in tons of BBC's running high rpm. I have the recommended spring pressure for the Morel's @ 190lb on the seat, it never seamed to float the valves and it always revved quickly to 6200 rpm. Some where there is an oil leak in the motor. I have messed with the distributor depth and now I was thinking about putting O-rings on the distributor. I don't want to run solids but we did it to prove a point that the hydraulics were hurting power. Also my distributor gear seems to have a lot of wear. I have a SERDI core cam with cast iron melanized distributor gear. I have been told the Titan pumps are notorious for beating up distributor and cam gears. I don't know if I should pull the motor and try to find if oil is coming out of somewhere it should not be, or if I should just band aid it and run it. Any suggestions would be great. Thanks, Tom.

another69
10-18-2016, 05:12 PM
Sounds like you have a really nice motor there. You could pull it apart now and figure out what's wrong before really hurting something. If nothing changed from the dyno to the installation in the car, what caused the oil pressure drop? Are you sure the guage is accurate? Do you have the option of putting it back on the dyno for a real apples to apples?

1BADBET
10-20-2016, 10:03 PM
I wonder what lobe is on the cam. Could be too aggressive for the hydraulic lifters and that's why solids made an improvement. I'm also wondering if the gauge or sending unit could be off. Had this problem with a customer once, thought he had way too much oil pressure at idle but it turned out his el cheapo gauge sat on 25lbs with the car off.... lol. That's what happens when you blow the budget on the engine and forget about all the other nickel dime stuff that adds up.

TBART70
10-21-2016, 03:21 AM
Straub designed the cam, don't know about the lobe. Holley EFI OPS sender, AutoMeter gauge and mechanical gauge screwed into back of block. All within 2-3 psi.

TBART70
02-04-2017, 05:38 PM
Hi all again. Been chasing oil pressure issues since day one. Went through 2 sets hydraulics and switched to solids, pin oiled first then non pin oiled to bring up oil pressure. Needless to say I pulled the motor due to a lot of metal in oil filter, and low oil pressure. The cam gear is wiped. Motor is getting redone. New cam, going from 108 LC to 110 LC. Hydraulic grind, solid Morel pin oiled lifters. Went with different cam company this time. Upping duration a touch, and lift on exhaust. Also doing 4/7 swap. It won't be installed as advanced as before. Will re-dyno with Carb like last time. Will have actual cam specs in a week or two. Trying to figure out what I need to do before it goes back in. Any suggestions would be greatly appreciated.

Thanks,
Tom

kimosabi
02-05-2017, 02:28 PM
Are you going to use the same distributor? What cam gear depth do you set it at

TBART70
02-05-2017, 04:06 PM
Are you going to use the same distributor? What cam gear depth do you set it at

Apparently not deep enough.

Same distributor, modified, and new cam billet core. Wearever gear on cam, new dist gear.