RIMCO, I wonder if they read the board?

norustscott · norustscott's Garage

Hello all,

I have finally recieved my 2.0l heads back from RIMCO...From the east coast this is an eight week effort and 75 bucks worth of UPS...

For the good stuff:

New seats
NewGuides
Welded up a couple of small plug boss cracks...all in all not a cheap undertaking. But what else is new with this addiction.

Now for the screwed up part. Heads look nice and fresh. bead blasted and clean. I noticed, however, that the head to cylinder surface area appeared to be resurfaced...flycut. The edge to the cumbusion chamber is way too sharp. Sharper than what I sent to CA.

I called RIMCO to find out how much material was removed. My question was answered with " we don't flycut 914 heads"

Before I freak, Can anyone substantiate this statement? RIMCO does not Flycut 914 heads??????

david c. · 01-06-2003, 07:49 PM

Scott,

Was there a reason given as to why they don't flycut the heads? As you know, I'm considering Rimco too. Shoot me an email off the board about your experience if you would.

Thanks,

John Rogers · 01-06-2003, 07:55 PM

I think Tutle's, Rimco, etc all do a cleanup cut or pass even if they say they don't. I have had heads repaired 6 times in the past 2 years and everytime a slight cut or polish (?) was made on the seating surface. I think it was what they do? Good luck

norustscott · norustscott's Garage

John, What do you think they remove? .002? more? If I leave everything the same before the heads came off, Then I am looking at a CR greater than the previous set up. 8.0:1. not to mention valve geometry. Have you ever had to add barrell shims after the "clean up"

Dave, I will have to email from work...home account down...

Zeke · 08:19 PM

The first time I took a head to RIMCO was in the late '70s. I have no reason to think that they don't do excellent work. However, they are not in the business of making high performance heads. They won't port, polish, cc the cambers or anything like that. They are strictly a machine shop. They do most of FAT Performance's rote work, but none of the mods. Your heads have been "surfaced." but not cut as they would not know how much you wanted cut. If you think the edge is too sharp and will cause pre-ignition beacause of hot spots, ease the edge with sandpaper.

BTW, RIMCO did most of my engine including balancing, but I sent the heads to someone else because I wanted some mods. $500 each. Do you still feel bad about your expense now even with shipping? I think EBS gets nearly $1000 each for the full monty.

John Rogers · 01-06-2003, 09:12 PM

The only way to tell what came off is to have measured them before they were sent. I doubt if it was much more than 0.001. I would do a VERY CAREFUL install and measure of the valve, rockers, push rods and measure the valve to piston clearance and I'd do it on both side. Is it a pain, yes, does it take time, yes, BUT it is much cheaper than breaking valves from the pistons hitting them! Good luck.

DuckRyder · 01-07-2003, 05:39 AM

I'd also like to hear about the your Rimco Experience. I've talked to them and they said they could do the chamber CC and have them ported and polished. I think it was Greg I talked to, he seemed quite nice and knowledgeable. Said something like 500-600.00 to do them right with stock size stainless valves and seats, weld up the Air holes and tap for sheet metal screws. (Thats a pair.) Up to around 900-1000 to do the “full monty”.

Adrian at Head Flow has not returned calls or E-Mail.

Shine Racing (who did the GM 914) said to call
“Import Machine”

and all the “locals” use
ProFlow Perfromace (Steve Sands)

Any one dealt with any of these?

Zeke · 01-07-2003, 06:46 AM

When I said "full monty," I meant six angle laser cut seats, port enlargement. flow bench with printout and big valves with bigger stems.

Robert, when you said you talked to Greg, Greg A. owns FAT, Todd is usually the one you talk to at RIMCO, right or wrong?

DuckRyder · 01-07-2003, 07:05 AM

Quote:

Originally posted by Zeke
Robert, when you said you talked to Greg, Greg A. owns FAT, Todd is usually the one you talk to at RIMCO, right or wrong?

I don't know if it is right or wrong, I called and had a long talk with him, it was pretty late. About 5 minutes later I realized I did not get his name and called back, the person who ansered than said everyone else left for the day but that I had been talking to Greg.

Is FAT and Rimco the ame place? I never called FAT.

hardflex · 01-07-2003, 07:06 AM

seems to me they have to make the head flat to seal with the cylinder. Even if they took of .005 it's effect on compression would be negligible. Given a choice i'd rather have heads that seal vs a little higher compression.

Isn't that why we all want euro pistons?

DuckRyder · 01-07-2003, 07:19 AM

wouldn't it raise the compression?

Zeke · 07:22 AM

Quote:

Originally posted by DuckRyder
I don't know if it is right or wrong, I called and had a long talk with him, it was pretty late. About 5 minutes later I realized I did not get his name and called back, the person who ansered than said everyone else left for the day but that I had been talking to Greg.

Is FAT and Rimco the ame place? I never called FAT.

Well, it's confusing to me and and didn't mean to confuse you. FAT Peformance is in Orange, CA near where the Angels play and RIMCO, or Riddle Machine Compnay, is in Santa Ana, not too far away. As I mentioned above, FAT sub-contracts basic machine work to RIMCO and charges a little more for it. Some people just take their stuff directly to RIMCO and they save a little money. If you are assembling the motor yourself, this seams like the way to go.

Also, Robert, I don't know this for a fact, but it seams reasonable to me that the arrangement between RIMCO and FAT (I don't know why we use all caps for thier spelling, but that's the way they both have it on their busness card) works both ways. It is possible that RIMCO subs the porting to FAT. I have seen the head room and flow bench at FAT. They are both impressive places, they are in large buildings with several emplyees. They are not backyard businesses run by individuals. Nothing wrong with small businesses mind you, I run one.

Jake Raby · 01-07-2003, 07:33 AM

If the surface is not cleaned up, the head is not rebuit.....I bet they do it.

I flycut the hell out of TIV heads, just do it right and take precautions and GO!!!

hardflex · 01-07-2003, 07:55 AM

DuckRyder- you may find this useful.

http://www.johnmaherracing.co.uk/enginecalc.htm

It calculates deck heights vs compression ratio's I think they have one in the tech section of this board. I've looked through various sites and the combustion chamber of a 2.0 head is about 56cc. On this site take 56 and add to it cc's of dish in your piston(In a flat top euro that would be zero) and that is your combustion chamber size. 2.0 bore and stroke is 94x71. Then your deck height. I"ve seen around here .040 is the minimum you can have. I haven't measured mine yet, so I took .050 as a WAG. Compression ratio was 8.7 to one. when I went to .045 dec it changed to 8.8 to 1, so .002 off the heads would add less than .1 compression. If you absolutely had to have the .002 back you can add a shim to the base of the cylinders. As I understand it measuring the combustion chamber cc's and setting the proper deck height for the compression you want is part of a quality job on these engines.

IMHO Rimco will do you right.

Zeke, do you know about what a stock deck height is?

Zeke · 08:29 AM

Quote:

Originally posted by hardflex

Zeke, do you know about what a stock deck height is?

Yes and no. The stock engine had a head gasket which had to be added to the cylinder height when determining overall deck. As soon as you remove the head gasket, you will have a smaller deck, but still bigger than optimum "squish." Squish, to be on the safe side, should be about .045. This gives good flame spread. I have heard of people running less, say .035, but it could be dicey and not with aluminum rods. A more direct answer to your question is that the factory tolerances did not provide for excatly the same deck in each cylinder. And if the motor has been rebuilt, it could be worse. What I did was measure the rod lengths and put the longest rod in where the deck was the biggest. When I finally got the best I could do, I had one piston top shaved (at RIMCO) .010 to equalize my decks. I adjusted my squish with cylider base shims which were all equal due to the fact that all piston/rod lengths were equal at this point. This ensures that the tops of the cyls are the same height so they fit into the heads perfectly. Of course the clys had been trued for length and squared before any of this (once again, at RIMCO). This is more info than you asked for, but there is no simple answer to the question because there are so many varilbles even amongst stock engines, IMO. But when you start getting down to .045, you can't afford to have one decking at .035, which I would have had w/o the shaving.

Edit: If you are removing the head gasket and installing rebuilt heads that have been "kissed" by the flycutter and you are not blueprinting the rods, cyls and pistons, you must add the thickness to the base of the cyl to be back at stock. This is the safe bet for partial rebuilds to run on low octane pump gas as the engine was originally intended.

hardflex · 01-07-2003, 08:42 AM

Rod length ? DOH! another variable

Zeke · 01-07-2003, 10:45 AM

Well, we are only talking a few thousandths here, but it all adds up. If you can get some of the matching work done while the parts are laying on the bench, you can sometimes work out the descrepancies w/o machining.

norustscott · norustscott's Garage

Ok...It appears that there was some misscommunication...RIMCO does flycut...or suface the cylinder ledge on type 4 heads...Confusion was reagrading the "profiling" of the "FINS" ???? They do not profile the fins on a type 4 head...

Anyway, They indicated that they took off somewhere between .008 and .010" It would have been nice for them to document the amount...

I still trying to figure out how out of bounds my last conversation wandered with Rimco...

RIMCO does flycut heads...they call it surfacing.

Cheers.

DuckRyder · 01-07-2003, 02:23 PM

Pictures would be swell....

DuckRyder · 01-07-2003, 02:35 PM

Oh, and:

Hardflex, thanks for the link that is pretty slick. I keep meaning to check out the spreadsheet from my laptop (which has office and thus Excel) but keep forgetting.

Zeke, RIMCO

said they could get the porting and polishing done, I guess they were talking about FAT. He did say he did not do that. We discussed several options to repair my heads, and had even talked about larger valves to repair the damage previously done (see the head thread) and also talked about the need to at least equalize teh cc on the chambers. He didn't say he didn't do that work, but I guess its possible that he didn't think it important since we had already talked about sending them out for bowl work to match in the larger valves.