Another lifter to bore clearance question

[Ohio Rob]

Hello all.
I’m building a 363 SBF in a Dart SHP block.
It’s at the machine shop at present.
The machinist called yesterday and advised that the lifter to bore clearance is .0025. I was surprised it wasn’t tighter, and as I expedited it to be with a dart block, I brought my lifters to be fitted. Block is on the high side and the lifters are on the low side.
I’m using a made in the USA set of comp cams solid roller lifters. (I bought them years ago before they offshored most of their stuff)

The engine will be a dry sump, drag race only engine. No street time and limited idle time.

I’m inclined to run the looser clearances.
My concerns are the loss of oil around the lifters and if .0025 will allow too much rocking in the bore.
I’m wondering if I should consider oil restrictions
To the lifter galleys.

Any input would be much appreciated.

Thanks,
Rob

[tenxal]

Honestly, I'd try to find a set that was bigger, at least by .0005, to get it at least to .0020.

The volume loss between .0025 and .0020 is quite significant.

[PackardV8]

He's got the block, he's got the lifters; how difficult is it to restrict the lifter oiling with the Dart SHP block?

[Joe-71]

Bronze bushing and hone to fit. Joe-71

[tenxal]

He's got the block, he's got the lifters; how difficult is it to restrict the lifter oiling with the Dart SHP block?

Any thoughts on his other concern re: the lifters rocking in the bores?

[Charliesauto]

Hello all.
I’m building a 363 SBF in a Dart SHP block.
It’s at the machine shop at present.
The machinist called yesterday and advised that the lifter to bore clearance is .0025. I was surprised it wasn’t tighter, and as I expedited it to be with a dart block, I brought my lifters to be fitted. Block is on the high side and the lifters are on the low side.
I’m using a made in the USA set of comp cams solid roller lifters. (I bought them years ago before they offshored most of their stuff)

The engine will be a dry sump, drag race only engine. No street time and limited idle time.

I’m inclined to run the looser clearances.
My concerns are the loss of oil around the lifters and if .0025 will allow too much rocking in the bore.
I’m wondering if I should consider oil restrictions
To the lifter galleys.

Any input would be much appreciated.

Thanks,
Rob

What you have described is not "ideal", but it should work. I would not worry about the "rocking" in the bore, I have ran stuff that loose with no issues.

How large is the pressure stage of your oil pump and what is your pump to crank pulley ratio?

If you have a decent size pressure section and ratio and you don't have ridiculous bearing clearances, your oil pressure will be fine @ .0025".

We maintain a 374 Ford built with a Ford 6010-351BOSS block, Crower HIPPO lifters, no oil restrictors, 1.000 pressure Daily pump @ 57%, Cleveland main size, lifter to bore is .0022"-.0025". Plenty of oil pressure.

Since you said "363", I assume you have 302 main size? If so, that will help with overall oil flow demand. If you have Cleveland main size, get some Daido main bearing from Callies. They have less eccentricity and will reduce your oil flow significantly, unfortunately, they are not available for 302 mains.

If you are still not comfortable with what you have, look at the BAM lifters. Their standard Ford size is .8737"(larger than Crower) and we have some customs made to .8741" just for oversize blocks, I have those in stock if you want a set. One nice feature of the BAMS is the OD sizing is the most consistent of any lifter manufacture we have seen, within .0002".

PM me if you want a set of .8737" or the custom .8741" lifters. I have them on the shelf with needle bearings or can have some built in a day or so with bushings.

[dwilliams]

I don't know if Ford officially changed their spec, but .0025" seemed to be normal for roller 5.0 blocks. Flat tappet blocks all seemed to be .001-.0015".

[Ohio Rob]

Thanks for the replies fellas.

I haven’t bought the pump pulleys yet. I have a Barnes pump that a friend has set aside for me. It’s a 5 stage. I’m not sure how wide the pressure stage is.

Yes, it’s a 302 architecture engine with standard 302 mains and rods. The dart block is priority main oiling.

[MELWAY]

A morel lifter will measure .0005”-.0008 bigger than your comp lifters. But I doubt you would have any issues at .0025” clear. I have seen worn out chevs around .0030. Ran fine but lifter body’s looked terrible

[rfoll]

I have seen and heard of many problems with Comp roller lifters, enough that I would never buy any. When a lifter comes apart, it starts eating expensive parts quite rapidly. You could sell them to someone you don't like and buy a different brand.

[novafornow]

The only lifters that I have ever had the fork spread on were comp. That was enough for me.

[stealth]

I have seen and heard of many problems with Comp roller lifters, enough that I would never buy any. When a lifter comes apart, it starts eating expensive parts quite rapidly. You could sell them to someone you don't like and buy a different brand.

Agree....I like this idea....