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all the good shit happens when l,m gone
 

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Discussion Starter · #22 ·
l,d stay with the smaller carb , because in a heavy truck you will never need that last bit of top end unless yer mud boggin

also 1985 is the first year for "rollers" on a 318 , the 360 didnt get them till 1988

who the fuk is == XD , did l miss something
XD is the face I make when I'm laughing my ass off. Thanks for your input.
 

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who the fuk is == XD , did l miss something
It's an emoticon for a smile or laugh, looking at it sideways, like smile : ) or wink ; )
 

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Ya a smaller carb for just putting around is fine, but if you want the power when you need it then I would go a little bigger. The fuel economy on my 650cfm Edelbrock was really good on my old .030 318. I've heard of guys running a flat tappet cam in a roller block but I've just never seen it firsthand.
 

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1985 may have been the first year for a roller 318 but it wont be a roller in a truck until TBI injection....Car engines may have been roller in 85....Ive had multiple 85-86 truck engines and all had the bosses for the hold down spider, none had a roller cam. TBI roller cam engines use the hold down spider...as have all the magnum engines Ive seen. When they switched form flat tappet to roller they didnt change the block....on the later LAs oil went thru hollow pushrods as well as through the rocker shafts. Magnum engines are not drilled for LA style rocker shaft oiling so youd need hollow pushrods.
 

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yes but the roller lifters were taller than the flat tappets and therefore they made the lifter bores taller also. At least from what I've seen.
 

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Discussion Starter · #27 ·
yes but the roller lifters were taller than the flat tappets and therefore they made the lifter bores taller also. At least from what I've seen.
Well maybe we will just have to get to the bottom of this. I'll measure the depth of the bores on my block tonight and maybe someone with a flat tappet only block can compare
 

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1985 may have been the first year for a roller 318 but it wont be a roller in a truck until TBI injection....Car engines may have been roller in 85....Ive had multiple 85-86 truck engines and all had the bosses for the hold down spider, none had a roller cam. TBI roller cam engines use the hold down spider...as have all the magnum engines Ive seen. When they switched form flat tappet to roller they didnt change the block....on the later LAs oil went thru hollow pushrods as well as through the rocker shafts. Magnum engines are not drilled for LA style rocker shaft oiling so youd need hollow pushrods.
according to all the info l have the roller came out 1981 -1983 in Cars with 4bl and TBI and everything else had it by 1985 / quote below

[ The 318 received roller lifters and a fast-burn cylinder head in 1985. Throttle-body electronic fuel injection was factory equipment on the 1981-1983 Imperial. From 1988 to 1991, another throttle-body fuel injection system was used for truck and van applications. ]

 

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if the valley has provisions for the roller lifter keepers then its a roller block ... ? just a wild guess .
 

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My 85 has the provisions so its def a roller block, but it has a flat tappet cam, hence my statement that you can swap from one to the other, dodge did it. I have seen 85 diplomat engines that were roller, but all the 85-86 truck engines I have seen have been flat tappet.....
 
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My 85 has the provisions so its def a roller block, but it has a flat tappet cam, hence my statement that you can swap from one to the other, dodge did it. I have seen 85 diplomat engines that were roller, but all the 85-86 truck engines I have seen have been flat tappet.....
I would say correct my 1986 truck, had a flat tappet, but had the spider hold down's and hollow pushrods. Basically was a homologation. Had 302 heads on it as well.... Have some pics round here somewhere....

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Check the casting number on your heads, roller 360 should have 308's. The rotator type retainer and short springs on the exhaust of these heads will cause spring bind with a taller cam. With that .490ish cam you will, not might, will... have to pitch the rotators in favor of intake retainers on the exhaust valves and have the spring pockets cut deeper to correct the installed height of the springs. I replaced the retainers without cutting the pockets because I was in a balls out rush to get to Moab for RamJam, the machine shop had already screwed up the new valve seats and I simply didn't have time to start over. My cam was .471 on the exhaust and it was really close on clearance. You'll need to pay attention to the valve guide height as well or the retainer will mash your valve stem seals.

I did a lot of grinding and bowl cleanup work on my 308's because the as cast ports were pretty bad. Note the lack of a third angle on the seats. Idiot Chevy boys machine shop.
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with out lapping or "bluing" its hard to see seats in photo . exhaust rotaters are "good" for longevity , but not performance uses . low comp heads with what appears to be WIDE seats ...
 

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with out lapping or "bluing" its hard to see seats in photo . exhaust rotaters are "good" for longevity , but not performance uses . low comp heads with what appears to be WIDE seats ...
Had 9.2 compression with those heads, but yeah, the local machine shop crapped all over them. Replaced them with Eddy RPM's.....after I fixed the things Edelbrock had crapped all over on those. Pretty sure my current build will be my last, it's gotten to be a real hassle getting decent work and parts.
 
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AGREED
 

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Discussion Starter · #36 · (Edited)
Check the casting number on your heads, roller 360 should have 308's. The rotator type retainer and short springs on the exhaust of these heads will cause spring bind with a taller cam. With that .490ish cam you will, not might, will... have to pitch the rotators in favor of intake retainers on the exhaust valves and have the spring pockets cut deeper to correct the installed height of the springs. I replaced the retainers without cutting the pockets because I was in a balls out rush to get to Moab for RamJam, the machine shop had already screwed up the new valve seats and I simply didn't have time to start over. My cam was .471 on the exhaust and it was really close on clearance. You'll need to pay attention to the valve guide height as well or the retainer will mash your valve stem seals.
I've heard that one could shorten the valve guide a couple thousands to create clearance for a cam of this size. My understanding is that the valve guide is where the problem is when it comes to max lift on these heads. Is this true? Are there any other problem areas I should keep an eye on?

I was looking at the 901-16 comp springs, do you think they would be good for my application?
With those springs, are you saying that I should put rotators on the springs underneath the retainers and then deepen the pockets to compensate for the change in height?
Are the rotators the reason for deepeing?

I want to get aluminum heads sometime in the next 12 months to replace the stock ones and of course that will include all new valvetrain as well.
I just want these current heads to be able to run for the time being, not exactly looking for optimal performance. At the same time, I don't want to do anything wrong. Do you think there's anything else I would need to do?
 

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I've heard that one could shorten the valve guide a couple thousands to create clearance for a cam of this size. My understanding is that the valve guide is where the problem is when it comes to max lift on these heads. Is this true? Are there any other problem areas I should keep an eye on?

I was looking at the 901-16 comp springs, do you think they would be good for my application?
With those springs, are you saying that I should put rotators on the springs underneath the retainers and then deepen the pockets to compensate for the change in height?

I want to get aluminum heads sometime in the next 12 months to replace the stock ones and of course that will include all new valvetrain as well.
I just want these current heads to be able to run for the time being, not exactly looking for optimal performance. At the same time, I don't want to do anything wrong. Do you think there's anything else I would need to do?
Nosir. You pitch the stock rotators in the trash and replace them with one piece retainers. The issue with the stock 308 valves is the location of the lock grooves in relation to the stem tip. The grooves are pretty far down on the stem to make room for the thickness of the factory rotator. Even with a deep cupped one piece retainer to help correct the installed height of the spring, the position of the locks on the stem remains the same. That's where the guide height issue is on the exhaust side. The lock grooves on the intakes are closer to the stem tip so there's more real estate available between the retainer and the guide.

Even with deep retainers the pockets may need to be cut to get the installed height right. Bind issues aside, installed height affects spring rate.

Fwiw I'd choose a roller over a flat tappet any day for the better lobe profile, and the lack of zinc in modern oils. I'm using the stock '90 roller wishbones and spider, with a Hughes cam, lifters and rockers on LA RPM heads. That required punching out the pushrod tunnels and custom length pushrods, but it gives the best of both worlds. What is in effect the Magnum roller cam setup, combined with the superior LA type shaft rockers.

Pushrod tunnels.

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Although shaft mount rockers are best, I think the Magnum heads are better overall. They flow better than the LA heads and the rocker studs in them are just fine for truck applications. To truly benefit from the shaft mount system in the LA heads is to go with aftermarket shaft rockers. IMO of course. Everything else you say i completely agree with. Keep the pics coming!
 
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