fastmaro

I was calling around and found out that Thunder Racing only ports their oil pumps for better flow, but they dont shim them. However, Texas Speed & Performance does. I know that the oil pumps that sponsors offer are all ported unless they're factory units, but why do some shim them and some dont? Is the increased oil pressure needed? I plan to purchase and install a new oil pump when installing my cam and want to be sure that I get the right one.

I came across a post in a search about if all ported pumps that the sponsors offer were the same and the answers were yes. But as I did some calling, some are shimmed and some arent. I'm still on the stock cam, but I guess my oil pressure seems to be normal.

cyphur

iTrader: (10)

Thunder outsources for the porting of their oil pumps. Talked to them yesterday about it actually. If TSP shims them, then I would go w/TSP. I'm porting my own right now and am looking for how much it should be shimmed.

fastmaro

What do you mean?

What's your reason behind going with the TSP unit since they shim them? Is the extra oil pressure needed? Can you have too much oil pressure?

fastmaro

Well here is my options, I can either purchase a ported pump that isnt shimmed from Thunder at the same time I order my cam, or I can purchase it seperately from TS&P and get the one that is shimmed. Just wondering what kind of benefit I would have with a shimmed pump? Either way doesn't matter to me, but if there is a reason to get one or the other, then I'll do so.

NLang

iTrader: (12)

Shimming of the releif valve spring creates more oil pressure.

fastmaro

I knew that, but when is it necessary for the extra oil pressure? Some sponsors have them shimmed and some dont. I could see if LS1s had a oil pressure issues then offered them shimmed for increased oil pressure, but what if Im not having any problems with oil pressure and then install a ported oil pump that's shimmed. I'm ordering my cam and oil pump today since those are the only 2 items left for the swap and was wondering which one to get.

KGSloan

if you have good pressure i dont feel the shimming is needed. my motor runs 60psi hot at 1000rpms. no shim, no porting of pump. then goes to 80 at wot, just like factory. not sure if you're motor has this kind of pressure but i see absolutely no need for anything more than that. just seems overkill.

ArKay99

iTrader: (1)

I believe Thunder Racing uses Katech oil pumps. I have one. I have posted on this issue a while ago. I was careful on my reinstall, I didn't use a dual chain roller, just a JWIS chain, so there was no stress on the o-ring. I used a new o-ring and made sure everything fit nice and there was no pinching. I get around 28-30psi at idle and around 60-65psi at WOT. I get around 35-40psi at cruise. The problem is I had 5psi more pressure across the board with my old oil pump. Also, I get a ticking with the new cam and stuff. The ticking goes away as soon as I get over 40psi and comes back when I get under 40psi for a few seconds. It's not bad, but if I knew how much to shim it to get that extra 5psi back it would make my day. I'm going back in soon to do some other work and to install a double roller timing chain and redegree my cam, so I can fix it up then, but how much?

CharlieLed

iTrader: (1)

YES, you can have too much oil pressure. There needs to be sufficient pressure to keep the bearings supplied with lubricant, if there is TOO much pressure then the soft material on the bearings can be washed away. Porting the oil pump is good in that it provides an unrestricted flow of oil through it; volume is good, pressure in extreme is not.

NLang

iTrader: (12)

My guess, start small. Maybe a 1/16" (.062) shim and see if you get that 5psi. You probably wouldn't want to shim a factory relief spring more than .125".

For those thinking 'if more pressure isn't necessary, why shim the spring?' You got it There's no need to try and fix what isn't broken...However, you can make it more efficient. What I mean by that is either try porting yourself, or purchase a ported pump. You should see more pressure accross the board, but not because of a tight pressure regulator, the pump is more efficient-it will move a slightly greater volume without a higher spring pressure. You're also removing some of the parasitic drag from the front of the engine as well because the oil flows more freely through the pump. Fractional loss of drag, but fractions are still numbers-they add up

fastmaro

Well Im going on 70k miles on the car and plan to install an oil pump when I change the camshaft. I havent had any oil pressure issues, so then there would be no need to get a ported oil pump that's shimmed correct? Just buy one thats ported and blueprinted, but that isnt shimmed?

NLang

iTrader: (12)

That's the route I'd take if you haven't any oiling issues.

cyphur

iTrader: (10)

I'm approached 66k right now, and I bought a plain LS6 pump and ported the **** out of it myself. Came out quite nicely. She'll get installed when I do my cam, no reason to break the seals any sooner.

I have 47psi during cruising, ~70-75 during WOT. I wouldn't say I need to shim right now, but its good info to know. Who knows what could happen.

Phil99vette

iTrader: (11)

I shimmed mine .100 and see 50-54psi cruising.

slow98Z

iTrader: (27)

where do you get the shims

L-EATER

iTrader: (2)

It has been my experience that honing and polishing the relief valve bore, to help with the sticking problem, allows some pressure to bleed off, thus the need to shim to recover that lost pressure. Maybe some porters hone the bore and some dont? I just used a flatwasher about .060 the last time.